The following comments have been submitted:
Comment #1Page Number: 9Paragraph / Figure / Table / Note: Equations 5A & 5BComment Intent: Not an ObjectionComment Type: TechnicalComment: I am looking for clarification as to why we correct the CFM50 with an additional 22% (for a single point test) or 11% (for multi-point test) when reporting results for a rating, code, or third party program. What is the methodology behind this and may we see the derivation of 22%? It appears that this calculation trumps any effort to correct the CFM50 for temperature and altitude. Response: Accept in principle The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
I am looking for clarification as to why we correct the CFM50 with an additional 22% (for a single point test) or 11% (for multi-point test) when reporting results for a rating, code, or third party program. What is the methodology behind this and may we see the derivation of 22%?
It appears that this calculation trumps any effort to correct the CFM50 for temperature and altitude.
Accept in principle
The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in:
Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
Comment #2Page Number: 5Paragraph / Figure / Table / Note: 3.4.1.5Comment Intent: Not an ObjectionComment Type: EditorialComment: The ACF calculation is poorly written and should use a standard scientific notation. Proposed Change: ACF = Altitude Correction Factor = 1 + 0.000006 6x10^(-6) x Altitude in feet, using the altitude measured in Section 3.3.4. Response: Reject The current language is clearer for most users than scientific notation.
The ACF calculation is poorly written and should use a standard scientific notation.
Reject
The current language is clearer for most users than scientific notation.
Comment #3Page Number: 12Paragraph / Figure / Table / Note: 4.3.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: 'Pressure probe' is vague. Generally it is well accepted that a static pressure probe is to be used so velocity pressure in the duct system does not affect results. Leakage can be underestimated if a total pressure reading is taken. As a general note, I would not allow the static pressure probe to be placed in either plenum if method 2 is used. Proposed Change: 4.3.2. The static pressure probe(s) for the Duct Leakage Tester shall be installed using one of the following options. Note: When using Method 1 for a duct system with more than three returns (based on the exception in Section 4.3), then Section 4.3.2.4 shall be used. 4.3.2.1. A single static pressure probe shall be located at the supply register closest to the air handler; or, 4.3.2.2. A single static pressure probe shall be located in the main supply trunk line, at least 5 feet from the air handler; or, 4.3.2.3. A single static pressure probe shall be located in the supply plenum; or, 4.3.2.4. A single static pressure probe shall be located according to Section 4.3.2.1, 4.3.2.2, or 4.3.2.3, and a second probe shall be located in the return plenum or in the closest return grill to the air handler. The return duct system pressure probe shall not be located in the airstream of the duct tester. Response: Accept Changes will be made to draft standard.
'Pressure probe' is vague. Generally it is well accepted that a static pressure probe is to be used so velocity pressure in the duct system does not affect results. Leakage can be underestimated if a total pressure reading is taken.
As a general note, I would not allow the static pressure probe to be placed in either plenum if method 2 is used.
Accept
Changes will be made to draft standard.
Comment #4Page Number: 9Paragraph / Figure / Table / Note: 5A and 5BComment Intent: ObjectionComment Type: TechnicalComment: Adding 22% to a blower door reading? Why are we making up new standards for measuring airflow now? Where in the world did this come from? Proposed Change: 3.5.2. If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b and the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b. Adjusted CFM50 = 1.22 x Corrected CFM50 (5a) Adjusted CMS50 = 1.22 x Corrected CMS50 (5b) Adjusted CFM50 = 1.1 x Corrected CFM50 (6a) Adjusted CMS50 = 1.1 x Corrected CMS50 (6b) Response: Accept in Principle The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
Adding 22% to a blower door reading? Why are we making up new standards for measuring airflow now? Where in the world did this come from?
3.5.2. If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b and the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b.
Adjusted CFM50 = 1.22 x Corrected CFM50 (5a) Adjusted CMS50 = 1.22 x Corrected CMS50 (5b)
Adjusted CFM50 = 1.1 x Corrected CFM50 (6a) Adjusted CMS50 = 1.1 x Corrected CMS50 (6b)
Accept in Principle
Comment #5Page Number: 16Paragraph / Figure / Table / Note: Section 5Comment Intent: ObjectionComment Type: EditorialComment: . Justification for Change This change is recommended to make the sectiion 5 title consistent with the body of section 5 which defines the scope to be measurement of the airflow of a ventilation system or a local mechanical exaust system. The technical basis for this recommendation is to clearly distinguish two types of directly measured airflows: 1. Flow of outside air into a residence via a mechanical ventilation system 2. Flow of inside air out of a residence via a local mechanical exhaust system Proposed Change: Proposed Change The section 5 title should be ammended to add "or Local Mechanical Exhaust System" to the end of the existing title: 5. Procedure for Measuring Airflow of Mechanical Ventilation Systems or Local Mechanical Exhaust Systems Response: Reject The term “Mechanical Ventilation”, as defined by ASHRAE 62.2-2013, is “the active process of supplying air to or removing air from an indoor space by powered equipment such as motor-driven fans and blowers but not by devices such as wind-driven turbine ventilators and mechanically operated windows.” Therefore, this term encompasses both whole-house ventilation systems and local mechanical exhaust systems. For brevity, the title of Section 5 will remain unchanged. As noted by the respondent, the Scope for Section 5 already clarifies that the procedure applies to both “a whole-house ventilation system (e.g., ventilation inlet on the return side of an HVAC system, HRV, ERV) or a local mechanical exhaust system (e.g., bathroom exhaust fan, kitchen exhaust fan)”.
.
Justification for Change
This change is recommended to make the sectiion 5 title consistent with the body of section 5 which defines the scope to be measurement of the airflow of a ventilation system or a local mechanical exaust system.
The technical basis for this recommendation is to clearly distinguish two types of directly measured airflows:
1. Flow of outside air into a residence via a mechanical ventilation system
2. Flow of inside air out of a residence via a local mechanical exhaust system
Proposed Change
The section 5 title should be ammended to add "or Local Mechanical Exhaust System" to the end of the existing title:
5. Procedure for Measuring Airflow of Mechanical Ventilation Systems or Local Mechanical Exhaust Systems
The term “Mechanical Ventilation”, as defined by ASHRAE 62.2-2013, is “the active process of supplying air to or removing air from an indoor space by powered equipment such as motor-driven fans and blowers but not by devices such as wind-driven turbine ventilators and mechanically operated windows.”
Therefore, this term encompasses both whole-house ventilation systems and local mechanical exhaust systems. For brevity, the title of Section 5 will remain unchanged. As noted by the respondent, the Scope for Section 5 already clarifies that the procedure applies to both “a whole-house ventilation system (e.g., ventilation inlet on the return side of an HVAC system, HRV, ERV) or a local mechanical exhaust system (e.g., bathroom exhaust fan, kitchen exhaust fan)”.
Comment #6Page Number: 83338Paragraph / Figure / Table / Note: New YorkComment Intent: ObjectionComment Type: GeneralComment: 6bjuRx http://www.QS3PE5ZGdxC9IoVKTAPT2DBYpPkMKqfz.com Proposed Change: 6bjuRx http://www.QS3PE5ZGdxC9IoVKTAPT2DBYpPkMKqfz.com Response: Spam
6bjuRx http://www.QS3PE5ZGdxC9IoVKTAPT2DBYpPkMKqfz.com
Spam
Comment #7Page Number: 4Paragraph / Figure / Table / Note: 3.3.4Comment Intent: ObjectionComment Type: TechnicalComment: 3.3.4. The altitude of the building site above sea level shall be recorded with an accuracy of 2000 ft (750 m) · This seems like a ridiculous margin of error. Altitude entry in TECTITE can change final BD number significantly. 500 – 1000 ft seems more realistic, especially given availability of GPS altitude data. (TF) Proposed Change: This seems like a ridiculous margin of error. Altitude entry in TECTITE can change final BD number significantly. 500 – 1000 ft seems more realistic, especially given availability of GPS altitude data. (TF) Response: Accept Draft will be changes to specify altitude within 500 ft (150 m).
3.3.4. The altitude of the building site above sea level shall be recorded with an accuracy of 2000 ft (750 m)
· This seems like a ridiculous margin of error. Altitude entry in TECTITE can change final BD number significantly. 500 – 1000 ft seems more realistic, especially given availability of GPS altitude data. (TF)
This seems like a ridiculous margin of error. Altitude entry in TECTITE can change final BD number significantly. 500 – 1000 ft seems more realistic, especially given availability of GPS altitude data. (TF)
Draft will be changes to specify altitude within 500 ft (150 m).
Comment #8Page Number: 2Paragraph / Figure / Table / Note: 3.2.2Comment Intent: ObjectionComment Type: TechnicalComment: 3.2.2. Attached garages. If attached garage is not within the pressure boundary of the house, exterior garage doors shall be opened. If attached garage is within the pressure boundary of the home, exterior garage doors shall be closed. In either case, windows in the attached garage shall be closed. The Air-Moving Fan shall only be permitted to be installed between the house and the garage if the garage is not within the pressure boundary of the house. Comment: · I do not see how the garage exterior garage door needs to be open for every test when the garage is outside the pressure boundary of the house. The garage is not air tight enough to impact the test. Are you also required to do a pressure boundary test to be able to properly define where the garage is? Why can’t we rely on the thermal envelope? · If the garage is within the pressure boundary of the house it should be included in the air leakage test. Volume and SQFT and the door between the house and the garage should be open. · If you are setting up in the door between the house and the garage the exterior garage door should be open for that test. Proposed Change: Comment: · I do not see how the garage exterior garage door needs to be open for every test when the garage is outside the pressure boundary of the house. The garage is not air tight enough to impact the test. Are you also required to do a pressure boundary test to be able to properly define where the garage is? Why can’t we rely on the thermal envelope? · If the garage is within the pressure boundary of the house it should be included in the air leakage test. Volume and SQFT and the door between the house and the garage should be open. · If you are setting up in the door between the house and the garage the exterior garage door should be open for that test. Response: Accept in principle The committee accepts that defining and measuring pressure boundaries can be problematic. However, rather than require open garage doors to outside, the section shall be change to require garage doors to be closed to outside. This better reflects the normal operating condition of the home and will result in more realistic ratings. This also makes the draft standard 380 consistent with RESNET 301, Chapter 8. The new language is: 3.2.2 Attached garages. All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door.
3.2.2. Attached garages. If attached garage is not within the pressure boundary of the house, exterior garage doors shall be opened. If attached garage is within the pressure boundary of the home, exterior garage doors shall be closed. In either case, windows in the attached garage shall be closed. The Air-Moving Fan shall only be permitted to be installed between the house and the garage if the garage is not within the pressure boundary of the house.
Comment:
· I do not see how the garage exterior garage door needs to be open for every test when the garage is outside the pressure boundary of the house. The garage is not air tight enough to impact the test. Are you also required to do a pressure boundary test to be able to properly define where the garage is? Why can’t we rely on the thermal envelope?
· If the garage is within the pressure boundary of the house it should be included in the air leakage test. Volume and SQFT and the door between the house and the garage should be open.
· If you are setting up in the door between the house and the garage the exterior garage door should be open for that test.
The committee accepts that defining and measuring pressure boundaries can be problematic. However, rather than require open garage doors to outside, the section shall be change to require garage doors to be closed to outside. This better reflects the normal operating condition of the home and will result in more realistic ratings. This also makes the draft standard 380 consistent with RESNET 301, Chapter 8.
The new language is: 3.2.2 Attached garages. All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door.
Comment #9Page Number: 2Paragraph / Figure / Table / Note: 3.2.3Comment Intent: ObjectionComment Type: TechnicalComment: 3.2.3. Crawlspaces. If a crawlspace is inside the conditioned space boundary, interior access doors and hatches between the house and the crawlspace shall be opened and exterior crawlspace access doors, vents, and hatches shall be closed. Comment: · Unless a transfer grill connects the house to the crawl space, in such cases it does not matter if the access door is open or shut Proposed Change: Comment: · Unless a transfer grill connects the house to the crawl space, in such cases it does not matter if the access door is open or shut Response: Reject Access grilles may provide too much air flow resistance so the access doors should be opened as stated in 3.2.3. Commenter provides no information to base his proposed change on.
3.2.3. Crawlspaces. If a crawlspace is inside the conditioned space boundary, interior access doors and hatches between the house and the crawlspace shall be opened and exterior crawlspace access doors, vents, and hatches shall be closed.
· Unless a transfer grill connects the house to the crawl space, in such cases it does not matter if the access door is open or shut
Access grilles may provide too much air flow resistance so the access doors should be opened as stated in 3.2.3. Commenter provides no information to base his proposed change on.
Comment #10Page Number: 9Paragraph / Figure / Table / Note: 3.5.2Comment Intent: Not an ObjectionComment Type: GeneralComment: 3.5.2. If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b and the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b. Adjusted CFM50 = 1.22 x Corrected CFM50 (5a) Adjusted CMS50 = 1.22 x Corrected CMS50 (5b) Adjusted CFM50 = 1.1 x Corrected CFM50 (6a) Adjusted CMS50 = 1.1 x Corrected CMS50 (6b) Comments: · I don’t understand this one, are we supposed to be adjusting what we get from Tectite? Should we have the software tools do this for us? This would lead to greeater consistency Proposed Change: Comments: · I don’t unde rstand this one, are we supposed to be adjusting what we get from Tectite? Should we have the software tools do this for us? This would lead to greeater consistency Response: Accept in principle The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
Adjusted CFM50 = 1.22 x Corrected CFM50 (5a)
Adjusted CMS50 = 1.22 x Corrected CMS50 (5b)
Adjusted CFM50 = 1.1 x Corrected CFM50 (6a)
Adjusted CMS50 = 1.1 x Corrected CMS50 (6b)
Comments:
· I don’t understand this one, are we supposed to be adjusting what we get from Tectite? Should we have the software tools do this for us? This would lead to greeater consistency
· I don’t unde rstand this one, are we supposed to be adjusting what we get from Tectite? Should we have the software tools do this for us? This would lead to greeater consistency
Comment #11Page Number: 12Paragraph / Figure / Table / Note: 4.3.2 - 4.3.2.4Comment Intent: ObjectionComment Type: TechnicalComment: 4.3.2. The pressure probe(s)for the Duct Leakage Testershall be installed using one of the following options. Note: When using Method 1 for a duct system with more than three returns (based on the exception in Section 4.3), then Section 4.3.2.4 shall be used. 4.3.2.1. A single pressure probe shall be located at the supply register closest to the air handler; or, 4.3.2.2. A single pressure probe shall be located in the main supply trunk line, at least 5 feet from the air handler; or, 4.3.2.3. A single pressure probe shall be located in the supply plenum; or, 4.3.2.4. A single pressure probe shall be located according to Section 4.3.2.1, 4.3.2.2, or 4.3.2.3,and a second probe shall be located in the return plenum or in the closest return grill to the air handler. The return duct system pressure probe shall not be located in the airstream of the duct tester. Comment: · We do not see many systems with more than 3 returns. This requirement is new to me and does not seem to be needed. I would think the issue is trying to ensure that the duct system is fully and uniformly pressurized. If this is what is trying to be accomplished I would think you would want to always install the pressure tap farther away from the furnace cabinet as you may be able to get to 25 close to the cabinet but not far away. If you reached 25PA far away from the cabinet you would be assured to have fully and uniformly pressurized the duct. Proposed Change: Comment: · We do not see many systems with more than 3 returns. This requirement is new to me and does not seem to be needed. I would think the issue is trying to ensure that the duct system is fully and uniformly pressurized. If this is what is trying to be accomplished I would think you would want to always install the pressure tap farther away from the furnace cabinet as you may be able to get to 25 close to the cabinet but not far away. If you reached 25PA far away from the cabinet you would be assured to have fully and uniformly pressurized the duct. Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, however, Section 4.3.2.4 requires the pressure probe to be placed in the return plenum or return grill closest to the air handler, rather than the furthest from the air handler, because the committee believes that this will better replicate actual operating conditions. The same logic applies to the requirement to locate the pressure probe on the supply side closer to the air handler, rather than further from the air handler.
4.3.2. The pressure probe(s)for the Duct Leakage Testershall be installed using one of the following options.
Note: When using Method 1 for a duct system with more than three returns (based on the exception in Section 4.3), then Section 4.3.2.4 shall be used.
4.3.2.1. A single pressure probe shall be located at the supply register closest to the air handler; or,
4.3.2.2. A single pressure probe shall be located in the main supply trunk line, at least 5 feet from the air handler; or,
4.3.2.3. A single pressure probe shall be located in the supply plenum; or,
4.3.2.4. A single pressure probe shall be located according to Section 4.3.2.1, 4.3.2.2, or 4.3.2.3,and a second probe shall be located in the return plenum or in the closest return grill to the air handler. The return duct system pressure probe shall not be located in the airstream of the duct tester.
· We do not see many systems with more than 3 returns. This requirement is new to me and does not seem to be needed. I would think the issue is trying to ensure that the duct system is fully and uniformly pressurized. If this is what is trying to be accomplished I would think you would want to always install the pressure tap farther away from the furnace cabinet as you may be able to get to 25 close to the cabinet but not far away. If you reached 25PA far away from the cabinet you would be assured to have fully and uniformly pressurized the duct.
The respondent does not propose a specific change to the standard, therefore the comment is rejected.
For context, however, Section 4.3.2.4 requires the pressure probe to be placed in the return plenum or return grill closest to the air handler, rather than the furthest from the air handler, because the committee believes that this will better replicate actual operating conditions.
The same logic applies to the requirement to locate the pressure probe on the supply side closer to the air handler, rather than further from the air handler.
Comment #12Page Number: 14Paragraph / Figure / Table / Note: 4.4.2.2 - 4.4.2.4Comment Intent: ObjectionComment Type: TechnicalComment: 4.4.2.2. With the Air-Moving Fan for the enclosure and the Duct Leakage Tester sealed and turned off, one measurement of the pressure difference across the enclosure shall be recorded, with the outside as the reference. The measurement shall represent the average value over at least a 10 second period and shall be defined as the Pre-Test Baseline Building Pressure. 4.4.2.3. The Air-Moving Fan for the enclosure shall be unsealed, turned on, and adjusted to create an induced enclosure pressure difference of 25 Pa (±0.5 Pa) (0.1 ±0.002 in. H2O ±0.002), defined as the induced enclosure pressure minus the Pre-Test Baseline Building Pressure. Note that this value is permitted to be positive or negative, which will be dependent upon whether the enclosure is pressurized or depressurized. If a 25 Pa (0.1 in. H2O) induced enclosure pressure difference cannot be achieved, then the highest possible value up to 25 (0.1 in. H2O) Pa shall be achieved with the equipment available. 4.4.2.4. The Duct Leakage Tester shall be unsealed, turned on, and adjusted to create an induced duct system pressure difference of 0.0 Pa (±0.5 Pa)(0.0±0.002in. H2O), relative to the house. If an induced duct system pressure difference of 0.0 Pa(0.0 in. H2O)cannot be achieved, the airflowof the Air-Moving Fan for the enclosure shall be reduced until an induced duct system pressure difference of 0.0 Pa(0.0 in. H2O)can be achieved. Comment: · I don’t understand why you are not pressurizing the duct and the house both to 25 PA. This is telling us to pressurize the house and then to unseal the Duct blaster? · · Maybe this is not a step by step write up and I am reading it incorrectly? If that is the case it should be reworded so ensure that after the baseline both the blower door and duct blaster covers are removed before the house is pressurized. Proposed Change: Comment: · I don’t understand why you are not pressurizing the duct and the house both to 25 PA. This is telling us to pressurize the house and then to unseal the Duct blaster? · · Maybe this is not a step by step write up and I am reading it incorrectly? If that is the case it should be reworded so ensure that after the baseline both the blower door and duct blaster covers are removed before the house is pressurized. Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, however, Section 4.4.2.3 requires the Air-Moving Fan to pressurize only the house to 25 Pa because the Duct Leakage Tester will subsequently pressurize the duct system to a relative pressure difference of 0 Pa with respect the house in Section 4.4.2.4. The net result of these two sections (and the subsequent sections to recheck the target pressures) will be that both the house and the duct system will be pressurized to 25 Pa, as intended.
4.4.2.2. With the Air-Moving Fan for the enclosure and the Duct Leakage Tester sealed and turned off, one measurement of the pressure difference across the enclosure shall be recorded, with the outside as the reference. The measurement shall represent the average value over at least a 10 second period and shall be defined as the Pre-Test Baseline Building Pressure.
4.4.2.3. The Air-Moving Fan for the enclosure shall be unsealed, turned on, and adjusted to create an induced enclosure pressure difference of 25 Pa (±0.5 Pa) (0.1 ±0.002 in. H2O ±0.002), defined as the induced enclosure pressure minus the Pre-Test Baseline Building Pressure. Note that this value is permitted to be positive or negative, which will be dependent upon whether the enclosure is pressurized or depressurized. If a 25 Pa (0.1 in. H2O) induced enclosure pressure difference cannot be achieved, then the highest possible value up to 25 (0.1 in. H2O) Pa shall be achieved with the equipment available.
4.4.2.4. The Duct Leakage Tester shall be unsealed, turned on, and adjusted to create an induced duct system pressure difference of 0.0 Pa (±0.5 Pa)(0.0±0.002in. H2O), relative to the house. If an induced duct system pressure difference of 0.0 Pa(0.0 in. H2O)cannot be achieved, the airflowof the Air-Moving Fan for the enclosure shall be reduced until an induced duct system pressure difference of 0.0 Pa(0.0 in. H2O)can be achieved.
· I don’t understand why you are not pressurizing the duct and the house both to 25 PA. This is telling us to pressurize the house and then to unseal the Duct blaster?
· · Maybe this is not a step by step write up and I am reading it incorrectly? If that is the case it should be reworded so ensure that after the baseline both the blower door and duct blaster covers are removed before the house is pressurized.
For context, however, Section 4.4.2.3 requires the Air-Moving Fan to pressurize only the house to 25 Pa because the Duct Leakage Tester will subsequently pressurize the duct system to a relative pressure difference of 0 Pa with respect the house in Section 4.4.2.4. The net result of these two sections (and the subsequent sections to recheck the target pressures) will be that both the house and the duct system will be pressurized to 25 Pa, as intended.
Comment #13Page Number: 15Paragraph / Figure / Table / Note: 4.4.2.5Comment Intent: ObjectionComment Type: GeneralComment: 4.4.2.5. The induced enclosure pressure difference shall be re-checked and, if necessary, the Air-Moving Fan for the enclosure shall be adjusted to maintain 25 Pa (0.1 in. H2O) or the highest achievable value up to 25 (0.1 in. H2O) Pa, per Section 4.4.2.3, or the airflow required to maintain an induced duct system pressure difference of 0.0 Pa (0.0 in. H2O), per Section 4.4.2.4. Comment: · Does this recheck happen after you unseal the Duct blaster? If you opened the duct blaster to pressurize the house then you would not have to check it again as described. Proposed Change: Comment: · Does this recheck happen after you unseal the Duct blaster? If you opened the duct blaster to pressurize the house then you would not have to check it again as described. Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, however, Section 4.4.2.5 does require the Rater to re-check the induced enclosure pressure difference after the duct blaster has been unsealed, turned on, and adjusted to create an induced duct system pressure difference of 0.0 Pa. Regardless of whether the house was initially pressurized to 25 Pa with or without the Duct Leakage Tester being unsealed, turning on the Duct Leakage Tester may alter the house pressure. Therefore, for consistency, the procedure instructs the Rater as to when to unseal the Duct Leakage Tester and to always recheck the pressures after the Air-Moving Fan and Duct Leakage Tester are both operational.
4.4.2.5. The induced enclosure pressure difference shall be re-checked and, if necessary, the Air-Moving Fan for the enclosure shall be adjusted to maintain 25 Pa (0.1 in. H2O) or the highest achievable value up to 25 (0.1 in. H2O) Pa, per Section 4.4.2.3, or the airflow required to maintain an induced duct system pressure difference of 0.0 Pa (0.0 in. H2O), per Section 4.4.2.4.
· Does this recheck happen after you unseal the Duct blaster? If you opened the duct blaster to pressurize the house then you would not have to check it again as described.
For context, however, Section 4.4.2.5 does require the Rater to re-check the induced enclosure pressure difference after the duct blaster has been unsealed, turned on, and adjusted to create an induced duct system pressure difference of 0.0 Pa.
Regardless of whether the house was initially pressurized to 25 Pa with or without the Duct Leakage Tester being unsealed, turning on the Duct Leakage Tester may alter the house pressure. Therefore, for consistency, the procedure instructs the Rater as to when to unseal the Duct Leakage Tester and to always recheck the pressures after the Air-Moving Fan and Duct Leakage Tester are both operational.
Comment #14Page Number: 15Paragraph / Figure / Table / Note: 4.4.2.6Comment Intent: ObjectionComment Type: EditorialComment: 4.4.2.6. The induced duct system pressure difference shall be re-checked and, if necessary, the Duct Leakage Tester shall be adjusted to maintain 0.0 Pa (±0.5 Pa) (0.0±0.002 in. H2O), per Section 4.4.2.4. Comment: · How is this different from above / 4.4.2.5 Proposed Change: Comment: · How is this different from above / 4.4.2.5 Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. The commenter should note that 4.4.2.5 is for the envelope pressure and 4.4.2.6 is for the duct pressure.
4.4.2.6. The induced duct system pressure difference shall be re-checked and, if necessary, the Duct Leakage Tester shall be adjusted to maintain 0.0 Pa (±0.5 Pa) (0.0±0.002 in. H2O), per Section 4.4.2.4.
· How is this different from above / 4.4.2.5
The commenter should note that 4.4.2.5 is for the envelope pressure and 4.4.2.6 is for the duct pressure.
Comment #15Page Number: ALLParagraph / Figure / Table / Note: ALLComment Intent: Not an ObjectionComment Type: GeneralComment: Why be different from ASTM E779 – 10? ASHRAE and and ASTM standards are already referenced at the end of this document. Proposed Change: Reference ASTM E779 – 10 Response: Reject ASTM E779 contains many additional requirements and measurements that add significantly to time and cost without improving the testing accuracy. Also - E779 does not include all the test procedures in this standard, e.g., single point pressurization testing. Nor does E779 create all the envelope leakage metrics discussed in the proposed standard.
Why be different from ASTM E779 – 10? ASHRAE and and ASTM standards are already referenced at the end of this document.
Reference ASTM E779 – 10
ASTM E779 contains many additional requirements and measurements that add significantly to time and cost without improving the testing accuracy. Also - E779 does not include all the test procedures in this standard, e.g., single point pressurization testing. Nor does E779 create all the envelope leakage metrics discussed in the proposed standard.
Comment #16Page Number: 1Paragraph / Figure / Table / Note: Section 3Comment Intent: Not an ObjectionComment Type: GeneralComment: Propose to recognize ASTM E779-10 as an approved test method in Section 3 in a similar way as test method A of ASTM E1554-13 is notes as approved in Section 4. Proposed Change: In addition to test proceedures in this section, ASTM E779-10 may be used. Response: Reject ASTM E779 contains many additional requirements and measurements that add significantly to time and cost without improving the testing accuracy. Also - E779 does not include all the test procedures in this standard, e.g., single point pressurization testing. Nor does E779 create all the envelope leakage metrics discussed in the proposed standard.
Propose to recognize ASTM E779-10 as an approved test method in Section 3 in a similar way as test method A of ASTM E1554-13 is notes as approved in Section 4.
In addition to test proceedures in this section, ASTM E779-10 may be used.
Comment #17Page Number: ALLParagraph / Figure / Table / Note: ALLComment Intent: Not an ObjectionComment Type: GeneralComment: Include a “Hazards” or Health and Safety like section similar to “7. Hazards” of ASTM E779 – 10 Proposed Change: While conducting test procedures, follow ASTM E779 – 10 “7. Hazards” Response: Accept in principle Draft standard will add the following text: “6. Hazards 6.1 Equipment Guards—The air-moving equipment shall have proper guards or cages to house the fan or blower and to prevent accidental access to any moving parts of the equipment. 6.2 Personal Protective Equipment—Use of safety equipment appropriate for general fieldwork is required; including safety shoes, dust masks/respirators, eye protection, hearing protection and hard hats. 6.5 Debris and Fumes—The blower or fan forces a large volume of air into or out of a building while in operation. Caution shall be exercised against sucking debris or exhaust gases from fireplaces and flues into the interior of the building. Care shall be exercised to prevent damage to internal furnishings, plants or pets due to influx of cold, warm or humid air. If the building will not remain unoccupied, except for testing personnel during the test, care shall be exercised regarding the potential for the fans to introduce respiratory hazards to the breathing zone of the occupied space. 6.6 Access and Working Space—The testing procedures for ventilation flow measurements may require the use of ladders and/or access to equipment rooms, unfinished attics, and other volumes containing air distribution ducting in the building that are not intended for occupancy. Caution must be exercised in these spaces to avoid injury and damage to the building.
Include a “Hazards” or Health and Safety like section similar to “7. Hazards” of ASTM E779 – 10
While conducting test procedures, follow ASTM E779 – 10 “7. Hazards”
Draft standard will add the following text:
“6. Hazards
6.1 Equipment Guards—The air-moving equipment shall have proper guards or cages to house the fan or blower and to prevent accidental access to any moving parts of the equipment.
6.2 Personal Protective Equipment—Use of safety equipment appropriate for general fieldwork is required; including safety shoes, dust masks/respirators, eye protection, hearing protection and hard hats.
6.5 Debris and Fumes—The blower or fan forces a large volume of air into or out of a building while in operation. Caution shall be exercised against sucking debris or exhaust gases from fireplaces and flues into the interior of the building. Care shall be exercised to prevent damage to internal furnishings, plants or pets due to influx of cold, warm or humid air. If the building will not remain unoccupied, except for testing personnel during the test, care shall be exercised regarding the potential for the fans to introduce respiratory hazards to the breathing zone of the occupied space.
6.6 Access and Working Space—The testing procedures for ventilation flow measurements may require the use of ladders and/or access to equipment rooms, unfinished attics, and other volumes containing air distribution ducting in the building that are not intended for occupancy. Caution must be exercised in these spaces to avoid injury and damage to the building.
Comment #18Page Number: 2Paragraph / Figure / Table / Note: 3.2.2Comment Intent: ObjectionComment Type: TechnicalComment: What is the pressure boundary? How is it determined? If the "pressure boundary" is determined to be the uninsulated garage wall, is the leakage between the intentional conditioned space and the intentional unconditioned space (garage) acceptable to RESNET from a health and safety perspective even when the building leakage is found to be within requirements? Proposed Change: Suggest changing to “Attached garages. If an attached garage is part of the house, the garage car entry door(s) shall be open during testing.” Response: Accept in Principle The committee accepts that defining and measuring pressure boundaries can be problematic. However, rather than require open garage doors to outside, the section shall be change to require garage doors to be closed to outside. This better reflects the normal operating condition of the home and will result in more realistic ratings. This also makes the draft standard 380 consistent with RESNET 301, Chapter 8. The new language is: 3.2.2 Attached garages. All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door.
What is the pressure boundary? How is it determined? If the "pressure boundary" is determined to be the uninsulated garage wall, is the leakage between the intentional conditioned space and the intentional unconditioned space (garage) acceptable to RESNET from a health and safety perspective even when the building leakage is found to be within requirements?
Suggest changing to “Attached garages. If an attached garage is part of the house, the garage car entry door(s) shall be open during testing.”
Comment #19Page Number: 3Paragraph / Figure / Table / Note: 3.2.10.2Comment Intent: ObjectionComment Type: TechnicalComment: Suggest changing 3.2.10.2 to read “shall be closed, but not sealed”, deleting 3.2.13 and adding 3.2.13 to 3.2.10.2 Proposed Change: Suggest changing 3.2.10.2 to read “shall be closed, but not sealed”, deleting 3.2.13 and adding 3.2.13 to 3.2.10.2 Response: Reject Non-dampered openings would not be sealed under normal house operation so they should not be sealed in this case. Plus we want to treat trickle vents separately from mechanical ventilation air inlets.
Suggest changing 3.2.10.2 to read “shall be closed, but not sealed”, deleting 3.2.13 and adding 3.2.13 to 3.2.10.2
Non-dampered openings would not be sealed under normal house operation so they should not be sealed in this case. Plus we want to treat trickle vents separately from mechanical ventilation air inlets.
Comment #20Page Number: 8-9Paragraph / Figure / Table / Note: 3.4.2.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: Suggest changing “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of induced enclosure pressure differences at approximately equally-spaces pressure stations…” to read, “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of 5 induced enclosure pressure differences at approximately equally-spaces pressure stations…” Proposed Change: Suggest changing “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of induced enclosure pressure differences at approximately equally-spaces pressure stations…” to read, “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of 5 induced enclosure pressure differences at approximately equally-spaces pressure stations…” Response: Accept in principle Changed the text slightly from the commenters recommendation to be: The Air-Moving Fan shall be unsealed, turned on, and adjusted to create at least five induced enclosure pressure differences at approximately equally-spaced pressure stations between 10 Pa (0.04 in. H2O) and either 60 Pa (0.24 in. H2O) or the highest achievable pressure difference up to 60 Pa.
Suggest changing “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of induced enclosure pressure differences at approximately equally-spaces pressure stations…” to read, “The Air-Moving Fan shall be unsealed, turned on, and adjusted to create a range of 5 induced enclosure pressure differences at approximately equally-spaces pressure stations…”
Changed the text slightly from the commenters recommendation to be:
The Air-Moving Fan shall be unsealed, turned on, and adjusted to create at least five induced enclosure pressure differences at approximately equally-spaced pressure stations between 10 Pa (0.04 in. H2O) and either 60 Pa (0.24 in. H2O) or the highest achievable pressure difference up to 60 Pa.
Comment #21Page Number: 9Paragraph / Figure / Table / Note: 3.4.2.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: Suggest changing “At each pressure station, the average value of the induced enclosure pressure difference, the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.” To read: “At each pressure station, the average value of the induced enclosure pressure difference, and the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.” Proposed Change: Suggest changing “At each pressure station, the average value of the induced enclosure pressure difference, the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.” To read: “At each pressure station, the average value of the induced enclosure pressure difference, and the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.” Response: Reject The recorded temperatures are needed to adjust the measured air flows for density changes.
Suggest changing “At each pressure station, the average value of the induced enclosure pressure difference, the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.” To read: “At each pressure station, the average value of the induced enclosure pressure difference, and the airflow, and the temperature, measured over at least a 10 second period, shall be recorded.”
The recorded temperatures are needed to adjust the measured air flows for density changes.
Comment #22Page Number: 9-10Paragraph / Figure / Table / Note: 3.5.2Comment Intent: Not an ObjectionComment Type: EditorialComment: Suggest changing “If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b and the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b.” Both tests are not required are they? Proposed Change: “If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b or the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b.” Response: Accept
Suggest changing “If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b and the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b.”
Both tests are not required are they?
“If the results of the building enclosure air leakage test are to be used for conducting a home energy rating or assessing compliance with a building enclosure leakage limit (e.g., defined by code or by an energy efficiency program), then the corrected airflow determined using a one-point test shall be adjusted using Equation 5a or 5b or the corrected airflow determined using a multi-point test shall be adjusted using Equation 6a or 6b.”
Comment #23Page Number: 3Paragraph / Figure / Table / Note: 3.2.10.2Comment Intent: Not an ObjectionComment Type: EditorialComment: If any changes are made to 3.2.10.2, then true up with 4.2.6.1 Proposed Change: If any changes are made to 3.2.10.2, then true up with 4.2.6.1 Response: Reject Non-dampered openings would not be sealed under normal house operation so they should not be sealed in this case. Plus we want to treat trickle vents separately from mechanical ventilation air inlets.
If any changes are made to 3.2.10.2, then true up with 4.2.6.1
Comment #24Page Number: 13Paragraph / Figure / Table / Note: 4.4.1.2Comment Intent: ObjectionComment Type: TechnicalComment: To follow manufacturer requirements on equipment, suggest changing to “The Duct Leakage Tester shall be turned on and adjusted to create an induced duct system pressure difference of 25 Pa (±0.5 Pa) with reference to outside.” Proposed Change: “The Duct Leakage Tester shall be turned on and adjusted to create an induced duct system pressure difference of 25 Pa (±0.5 Pa) with reference to outside.” Response: Accept
To follow manufacturer requirements on equipment, suggest changing to “The Duct Leakage Tester shall be turned on and adjusted to create an induced duct system pressure difference of 25 Pa (±0.5 Pa) with reference to outside.”
“The Duct Leakage Tester shall be turned on and adjusted to create an induced duct system pressure difference of 25 Pa (±0.5 Pa) with reference to outside.”
Comment #25Page Number: 15Paragraph / Figure / Table / Note: 4.4.2.7Comment Intent: Not an ObjectionComment Type: TechnicalComment: Suggest changing bullet point two to “If a 25 PA (o.1 in H2O) induced enclosure pressure difference cannot be achieved, then the average values of each test from 4.4.2.7, measured over at least a 10 second period, shall be recorded.” Proposed Change: “If a 25 PA (o.1 in H2O) induced enclosure pressure difference cannot be achieved, then the average values of each test from 4.4.2.7, measured over at least a 10 second period, shall be recorded.” Response: Reject It is technically incorrect to average together lower pressure difference values. The value closest to 25 Pa is the right one to use in this case.
Suggest changing bullet point two to “If a 25 PA (o.1 in H2O) induced enclosure pressure difference cannot be achieved, then the average values of each test from 4.4.2.7, measured over at least a 10 second period, shall be recorded.”
“If a 25 PA (o.1 in H2O) induced enclosure pressure difference cannot be achieved, then the average values of each test from 4.4.2.7, measured over at least a 10 second period, shall be recorded.”
It is technically incorrect to average together lower pressure difference values. The value closest to 25 Pa is the right one to use in this case.
Comment #26Page Number: There are noneParagraph / Figure / Table / Note: 3Comment Intent: ObjectionComment Type: TechnicalComment: General Comments: The new 380 standard has numerous serious shortcomings in the section on testing the airtightness of buildings that do not exist with the corresponding section of Chapter 8. The existing Chapter 8 standard is a consensus standard that was developed by a well-balanced RESNET technical committee consisting of many of the industry’s technical experts and representatives of the major manufacturers of testing equipment. The committee spent hundreds of hours considering various test approaches and issues relating field usability and data quality. In the end, the existing Chapter 8 standard was determined by the RESNET technical committee to represent a balanced approach that was both technically defensible and user friendly. The new standard 380 ignores many of technical advantages provided by the existing Chapter 8 standard, and fails to provide the field technician with the feed-back necessary to assure good data quality. The airtightness test procedures in Chapter 8 are relatively new and just now beginning to be widely accepted and used in the field after 2 years of frequent presentation at conferences and training sessions. Making major changes will be confusing, unpopular and just doesn’t make technical or administrative sense. Technical Comments: My biggest concern is that test uncertainties are not properly accounted for in the proposed standard. Due to the lack of measurement or calculation of test uncertainties, there is no useful feedback given to the technician, or other interested parties, on the effect of wind induced pressure fluctuations on the accuracy of the test. This omission can allow for technically “bad” test results to be accepted as legitimate, without anyone, including the technician or the party using the test results, to know better. Consider the following example of a multi-point airtightness test conducted on a house on a very windy day: The house can only be pressurized to 25 Pa due to the fact that it is either very large, very leaky or due to limitations of the test equipment. A 10-second pre-test baseline reading is taken, followed by three 10-second induced pressure stations (or even two pressure stations since no minimum number of stations is specified in the proposed standard), and then a final 10-second post-test baseline reading is taken. A regression analysis is then performed using the test data. Because of the windy conditions, the test results could possibly have a correlation coefficient of 0.5 or lower, an exponent of 0.3 and a 95% confidence interval of the CFM50 of +/- 200%. Despite the fact that this test data is simply not valid and should not be used, the proposed 380 standard simply has the technician multiply the resulting calculated CFM50 by 1.1 to account for test uncertainty (where did 1.1 come from?) and assume that it’s a perfectly valid test. The proposed 380 standard can easily create situations where houses are incorrectly identified as passing or as failing. The existing Chapter 8 standard invalidates tests when the results are not valid, and provides a robust method to account for the uncertainty of each test and the environmental conditions under which it is performed. The method to calculate ELA has also been changed, and this change along with the acceptance of “bad” test data mentioned above, means that extrapolating results to 4 Pa using data with the wrong exponent can give a result that is off by much more than the previous example without any penalty at all! This is not only totally unacceptable, it is just plain wrong-headed. The existing Chapter 8 standard changed the method of calculating ELA so that this situation would not occur. If someone does a 1 point test with a gauge having 1% accuracy, on a house that can be pressurized to 50 Pa on a day with no wind, they will get very accurate results. Yet in this situation, the proposed standard requires the technician to multiply the resulting CFM50 by 1.22. (Where did this number come from?) The automatic uncertainty adjustment factors of 1.1 or 1.22 contained in the proposed standard, if used to test houses for code compliance will automatically make the airtightness requirement for new houses 10 to 22% tighter. At 3 ACH50, the 2012 code for most of the country a house will actually have to be between 2.46 and 2.73 ACH50 to pass, depending on which test is used. The procedures in Chapter 8 do not have this effect. If additional adjustment is made for the fact that the manometer is allowed to be off by an additional 4% (i.e. the proposed standard reduces the accuracy requirements of manometers from 1% to 5%) these numbers go to 2.38 and 2.65 ACH50. Builders are already going to have a hard enough time getting to 3 without this additional penalty. Rather than applying a fixed uncertainty adjustment factor, the existing Chapter 8 standard provides a robust method to account for the uncertainty of each test and the environmental conditions under which it is performed. All 3 tests in Chapter 8 deal very adequately and reasonably with these situations. Yes, it’s a little more complicated to calculate and look at the uncertainties, but when everyone uses software that is available for free, it really isn’t more complicated or time consuming at all. Our TECTITE software has had the Chapter 8 test procedure and report generation in it for 2 years, is widely used, and doesn’t seem to be a problem for people at all. Testers can easily increase the precision of their measurement, when needed, by lengthening the sample time or increasing the number of data points. The Chapter 8 committee worked very hard to make the tests flexible and easy to use and Standard 380 completely undoes all of this and I think this is a huge mistake. The Repeated Single Point Test in Section 802.7 of chapter 8 gives the most accurate CFM50 result in a given amount of time due to not wasting time measuring at pressures other than 50 and allowing more data to be taken at 50. It also gives the most accurate estimate of the uncertainties due to not having to make invalid assumptions in making the regression calculations of uncertainties and having a separate baseline for each of the induced pressure points. But this test was omitted from the proposed standard, which makes no sense to me. Comments on the Process: The Chapter 8 committee was a well balanced committee consisting of many of the industry’s technical experts. The major manufacturers of test equipment were represented. Michael Blasnik, probably the most knowledgeable statistician in our industry and also an expert on the use of blower doors, the analysis of blower door data, and the uncertainties of blower door tests was heavily involved in the development of the uncertainty analyses in the chapter 8 tests. The committee worked very hard for hundreds of hours to complete Chapter 8. I volunteered to be part of the standard 380 committee and was told by several people that it probably wasn’t important to be involved because the committee was merely going to make editorial changes to meet the requirements of an ANSI standard. I think it was wrong to not to have consulted with all the Chapter 8 contributors when it was clear that major changes were being made. I recommend that in the future every attempt be made to involve all interested parties as corresponding members, if they are interested. I don’t know if this is a requirement of ANSI but it is something that many ANSI organizations do (ASHRAE, ASTM) so it must at least be allowed. The process used by RESNET in the development of Chapter 8 seemed much more open and inclusive than that used for Standard 380. Proposed Change: Recommended change: Delete paragraphs 3. To 3.5.3 and replace with paragraphs 802 to 802.9 of the “RESNET Mortgage Industry National Home Energy Rating System Standards” Response: Accept in principle The problem with lack of stations by specifying a minimum number of stations. The standard will be changed to: 3.4.2.2. The Air-Moving Fan shall be unsealed, turned on, and adjusted to create at least five induced enclosure pressure differences at approximately equally-spaced pressure stations between 10 Pa (0.04 in. H2O) and either 60 Pa (0.24 in. H2O) or the highest achievable pressure difference up to 60 Pa. The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
General Comments:
The new 380 standard has numerous serious shortcomings in the section on testing the airtightness of buildings that do not exist with the corresponding section of Chapter 8.
The existing Chapter 8 standard is a consensus standard that was developed by a well-balanced RESNET technical committee consisting of many of the industry’s technical experts and representatives of the major manufacturers of testing equipment. The committee spent hundreds of hours considering various test approaches and issues relating field usability and data quality. In the end, the existing Chapter 8 standard was determined by the RESNET technical committee to represent a balanced approach that was both technically defensible and user friendly.
The new standard 380 ignores many of technical advantages provided by the existing Chapter 8 standard, and fails to provide the field technician with the feed-back necessary to assure good data quality. The airtightness test procedures in Chapter 8 are relatively new and just now beginning to be widely accepted and used in the field after 2 years of frequent presentation at conferences and training sessions. Making major changes will be confusing, unpopular and just doesn’t make technical or administrative sense.
Technical Comments:
My biggest concern is that test uncertainties are not properly accounted for in the proposed standard. Due to the lack of measurement or calculation of test uncertainties, there is no useful feedback given to the technician, or other interested parties, on the effect of wind induced pressure fluctuations on the accuracy of the test. This omission can allow for technically “bad” test results to be accepted as legitimate, without anyone, including the technician or the party using the test results, to know better.
Consider the following example of a multi-point airtightness test conducted on a house on a very windy day: The house can only be pressurized to 25 Pa due to the fact that it is either very large, very leaky or due to limitations of the test equipment. A 10-second pre-test baseline reading is taken, followed by three 10-second induced pressure stations (or even two pressure stations since no minimum number of stations is specified in the proposed standard), and then a final 10-second post-test baseline reading is taken. A regression analysis is then performed using the test data. Because of the windy conditions, the test results could possibly have a correlation coefficient of 0.5 or lower, an exponent of 0.3 and a 95% confidence interval of the CFM50 of +/- 200%.
Despite the fact that this test data is simply not valid and should not be used, the proposed 380 standard simply has the technician multiply the resulting calculated CFM50 by 1.1 to account for test uncertainty (where did 1.1 come from?) and assume that it’s a perfectly valid test. The proposed 380 standard can easily create situations where houses are incorrectly identified as passing or as failing. The existing Chapter 8 standard invalidates tests when the results are not valid, and provides a robust method to account for the uncertainty of each test and the environmental conditions under which it is performed.
The method to calculate ELA has also been changed, and this change along with the acceptance of “bad” test data mentioned above, means that extrapolating results to 4 Pa using data with the wrong exponent can give a result that is off by much more than the previous example without any penalty at all! This is not only totally unacceptable, it is just plain wrong-headed. The existing Chapter 8 standard changed the method of calculating ELA so that this situation would not occur.
If someone does a 1 point test with a gauge having 1% accuracy, on a house that can be pressurized to 50 Pa on a day with no wind, they will get very accurate results. Yet in this situation, the proposed standard requires the technician to multiply the resulting CFM50 by 1.22. (Where did this number come from?) The automatic uncertainty adjustment factors of 1.1 or 1.22 contained in the proposed standard, if used to test houses for code compliance will automatically make the airtightness requirement for new houses 10 to 22% tighter. At 3 ACH50, the 2012 code for most of the country a house will actually have to be between 2.46 and 2.73 ACH50 to pass, depending on which test is used. The procedures in Chapter 8 do not have this effect.
If additional adjustment is made for the fact that the manometer is allowed to be off by an additional 4% (i.e. the proposed standard reduces the accuracy requirements of manometers from 1% to 5%) these numbers go to 2.38 and 2.65 ACH50. Builders are already going to have a hard enough time getting to 3 without this additional penalty. Rather than applying a fixed uncertainty adjustment factor, the existing Chapter 8 standard provides a robust method to account for the uncertainty of each test and the environmental conditions under which it is performed.
All 3 tests in Chapter 8 deal very adequately and reasonably with these situations. Yes, it’s a little more complicated to calculate and look at the uncertainties, but when everyone uses software that is available for free, it really isn’t more complicated or time consuming at all. Our TECTITE software has had the Chapter 8 test procedure and report generation in it for 2 years, is widely used, and doesn’t seem to be a problem for people at all. Testers can easily increase the precision of their measurement, when needed, by lengthening the sample time or increasing the number of data points. The Chapter 8 committee worked very hard to make the tests flexible and easy to use and Standard 380 completely undoes all of this and I think this is a huge mistake.
The Repeated Single Point Test in Section 802.7 of chapter 8 gives the most accurate CFM50 result in a given amount of time due to not wasting time measuring at pressures other than 50 and allowing more data to be taken at 50. It also gives the most accurate estimate of the uncertainties due to not having to make invalid assumptions in making the regression calculations of uncertainties and having a separate baseline for each of the induced pressure points. But this test was omitted from the proposed standard, which makes no sense to me.
Comments on the Process:
The Chapter 8 committee was a well balanced committee consisting of many of the industry’s technical experts. The major manufacturers of test equipment were represented. Michael Blasnik, probably the most knowledgeable statistician in our industry and also an expert on the use of blower doors, the analysis of blower door data, and the uncertainties of blower door tests was heavily involved in the development of the uncertainty analyses in the chapter 8 tests. The committee worked very hard for hundreds of hours to complete Chapter 8. I volunteered to be part of the standard 380 committee and was told by several people that it probably wasn’t important to be involved because the committee was merely going to make editorial changes to meet the requirements of an ANSI standard. I think it was wrong to not to have consulted with all the Chapter 8 contributors when it was clear that major changes were being made. I recommend that in the future every attempt be made to involve all interested parties as corresponding members, if they are interested. I don’t know if this is a requirement of ANSI but it is something that many ANSI organizations do (ASHRAE, ASTM) so it must at least be allowed. The process used by RESNET in the development of Chapter 8 seemed much more open and inclusive than that used for Standard 380.
Recommended change:
Delete paragraphs 3. To 3.5.3 and replace with paragraphs 802 to 802.9 of the “RESNET Mortgage Industry National Home Energy Rating System Standards”
The problem with lack of stations by specifying a minimum number of stations. The standard will be changed to:
3.4.2.2. The Air-Moving Fan shall be unsealed, turned on, and adjusted to create at least five induced enclosure pressure differences at approximately equally-spaced pressure stations between 10 Pa (0.04 in. H2O) and either 60 Pa (0.24 in. H2O) or the highest achievable pressure difference up to 60 Pa.
Comment #27Page Number: There are no page numbersParagraph / Figure / Table / Note: TitleComment Intent: ObjectionComment Type: EditorialComment: The term "air leakage" has 2 distinct meanings that are often confused. Standards should not be confusing; they should be written to be as clear as possible. Air leakage can refer to the amount of air that leaks through the holes in the enclosure during a test where the enclosure is subjected to a uniform induced pressure with a calibrated fan. This is the definition that is intended in Standard 380. Airtightness is also used to mean the same thing. But air leakage can also mean the amount of air leaking through the holes in an enclosure under normal operating conditions. This is often the first thing people think of when they hear the term air leakage test but it is not at all what is being dealt with in Standard 380. The Chapter 8 subcommittee discussed this in detail and decided to use the term “airtightness” because it cannot be misinterpreted in this way and makes it more clear what is being dealt with. The ABAA/ASTM standard for airtightness testing which is currently out for public review uses the word “airtightness” for this same reason. There are other standards that do use the term “air leakage” when referring to airtightness, but this isn’t a good reason to keep using it when a much clearer word exists and is commonly used to mean the same thing. Proposed Change: The words “air leakage” in the title of the standard and wherever it occurs in the body of the standard should be changed to “airtightness”. Response: Accept
The term "air leakage" has 2 distinct meanings that are often confused. Standards should not be confusing; they should be written to be as clear as possible. Air leakage can refer to the amount of air that leaks through the holes in the enclosure during a test where the enclosure is subjected to a uniform induced pressure with a calibrated fan. This is the definition that is intended in Standard 380. Airtightness is also used to mean the same thing. But air leakage can also mean the amount of air leaking through the holes in an enclosure under normal operating conditions. This is often the first thing people think of when they hear the term air leakage test but it is not at all what is being dealt with in Standard 380. The Chapter 8 subcommittee discussed this in detail and decided to use the term “airtightness” because it cannot be misinterpreted in this way and makes it more clear what is being dealt with. The ABAA/ASTM standard for airtightness testing which is currently out for public review uses the word “airtightness” for this same reason. There are other standards that do use the term “air leakage” when referring to airtightness, but this isn’t a good reason to keep using it when a much clearer word exists and is commonly used to mean the same thing.
The words “air leakage” in the title of the standard and wherever it occurs in the body of the standard should be changed to “airtightness”.
Comment #28Page Number: There are noneParagraph / Figure / Table / Note: 3.1.2Comment Intent: ObjectionComment Type: TechnicalComment: Chapter 8 specified a pressure measurement accuracy of +/- 1% of reading for good reasons. The major manufacturers of airtightness testing equipment, who participated in the writing of Chapter 8 and who agreed with this requirement, have been providing gauges that meet the 1% of reading accuracy as standard components of their airtightness testing equipment for over 10 years. It makes absolutely no sense to allow less accurate gauges to be used. The extra cost to the manufacturer for a sensor with 1% versus 5% accuracy is well under $10. The cost to a builder who has a house fail an airtightness test because of a 5% error in pressure measurements can be in the thousands of dollars. The words "of reading" need to be added after the 1% because it is otherwise not clear whether it is meant to be 1% of reading or 1% of full scale. Both are commonly used and standards have to be written to be as unambigous as possible. Proposed Change: Section 3.1.2. Specifies a manometer with an accuracy equal to or better than +/- 5 % or .25 Pa whichever is greater. The 5 % should be changed to 1 % and the words "of reading" should be added after 1%. Note that I tried to use track changes but could not get it to work correctly. Response: Accept
Chapter 8 specified a pressure measurement accuracy of +/- 1% of reading for good reasons. The major manufacturers of airtightness testing equipment, who participated in the writing of Chapter 8 and who agreed with this requirement, have been providing gauges that meet the 1% of reading accuracy as standard components of their airtightness testing equipment for over 10 years. It makes absolutely no sense to allow less accurate gauges to be used. The extra cost to the manufacturer for a sensor with 1% versus 5% accuracy is well under $10. The cost to a builder who has a house fail an airtightness test because of a 5% error in pressure measurements can be in the thousands of dollars. The words "of reading" need to be added after the 1% because it is otherwise not clear whether it is meant to be 1% of reading or 1% of full scale. Both are commonly used and standards have to be written to be as unambigous as possible.
Section 3.1.2. Specifies a manometer with an accuracy equal to or better than +/- 5 % or .25 Pa whichever is greater. The 5 % should be changed to 1 % and the words "of reading" should be added after 1%.
Note that I tried to use track changes but could not get it to work correctly.
Comment #29Page Number: There are noneParagraph / Figure / Table / Note: DefinitionsComment Intent: Not an ObjectionComment Type: GeneralComment:Proposed Change: Definitions. There should be a section that includes all the definitions that are necessary for a clear understanding of the standard. I understand that RESNET has been putting all definitions in one place in their National Mortgage… document. But I believe that Standard 380 is intended to be a stand-alone document. It needs its own section on definitions of terms that must be clearly understood for the use of the standard. Response: Accept in principle A definitions section will be added as follows: Blower Door – A device that combines an Air-Moving Fan as defined in Section 3.1.1, an Airflow Meter as defined in Section 3.1.3, and a covering to integrate the Air-Moving Fan into the building opening. Conditioned Floor Area (CFA) – The floor area of the Conditioned Space Volume within a building, minus the floor area of attics, floor cavities, and crawlspaces. The following specific spaces are addressed to ensure consistent application of this definition: · The floor area of a wall cavity that is Conditioned Space Volume shall be included. · The floor area of a basement shall only be included if the Rater has obtained a Manual J, S, and D report and verified that both the heating and cooling equipment and distribution system are designed to offset the entire design load of the volume. · The floor area of a garage shall be excluded, even if it is conditioned. · The floor area of a thermally isolated sunroom shall be excluded. · The floor area of an attic shall be excluded, even if it is Conditioned Space Volume. · The floor area of a floor cavity shall be excluded, even if it is Conditioned Space Volume. · The floor area of a crawlspace shall be excluded, even if it is Conditioned Space Volume. Conditioned Space Volume - The volume within a building serviced by a space heating or cooling system designed to maintain space conditions at 78 °F (26 °C) for cooling and 68 °F (20 °C) for heating. The following specific spaces are addressed to ensure consistent application of this definition: · If the volume both above and below a floor cavity meets this definition, then the volume of the floor cavity shall also be included. Otherwise the volume of the floor cavity shall be excluded. · If the volume of one or both of the spaces horizontally adjacent to a wall cavity meets this definition, then the volume of the wall cavity shall also be included. Otherwise, the volume of the wall cavity shall be excluded. · The volume of a vented attic shall be excluded. · The volume of a vented crawlspace shall be excluded. · The volume of a garage shall be excluded, even if it is conditioned. · The volume of a thermally isolated sunroom shall be excluded. · The volume of an unvented attic, an unvented crawlspace, or a basement shall only be included if the Rater has obtained a Manual J, S, and D report and verified that both the heating and cooling equipment and distribution system are designed to offset the entire design load of the volume. Crawl Space-A shallow unfinished space, beneath the first floor or under the roof of a building allowing access to wiring or plumbing. Infiltration Volume – The sum of the Conditioned Space Volume and Unconditioned Space Volume in the dwelling unit, minus the volume of floor cavities that have Unconditioned Space Volume both above and below, unconditioned wall cavities, vented attics, vented crawlspaces, garages, and thermally isolated sunrooms. Unconditioned Space Volume - The volume within a building that is not Conditioned Space Volume but which may contain heat sources or sinks that influence the temperature of the area or room. The following specific spaces are addressed to ensure consistent application of this definition: · The volume of a floor cavity shall be included, unless the volume both above and below the floor cavity meets the definition of Conditioned Space Volume. · The volume of a wall cavity shall be included, unless the wall cavity meets the definition of Conditioned Space Volume. · The volume of a vented attic shall be included. · The volume of a vented crawlspace shall be included. · The volume of a garage shall be included, even if it is conditioned. · The volume of a thermally isolated sunroom shall be included. · The volume of an unvented attic, an unvented crawlspace, or a basement shall be included unless it meets the definition of Conditioned Space Volume.
Definitions. There should be a section that includes all the definitions that are necessary for a clear understanding of the standard. I understand that RESNET has been putting all definitions in one place in their National Mortgage… document. But I believe that Standard 380 is intended to be a stand-alone document. It needs its own section on definitions of terms that must be clearly understood for the use of the standard.
A definitions section will be added as follows:
Blower Door – A device that combines an Air-Moving Fan as defined in Section 3.1.1, an Airflow Meter as defined in Section 3.1.3, and a covering to integrate the Air-Moving Fan into the building opening.
Conditioned Floor Area (CFA) – The floor area of the Conditioned Space Volume within a building, minus the floor area of attics, floor cavities, and crawlspaces. The following specific spaces are addressed to ensure consistent application of this definition:
· The floor area of a wall cavity that is Conditioned Space Volume shall be included.
· The floor area of a basement shall only be included if the Rater has obtained a Manual J, S, and D report and verified that both the heating and cooling equipment and distribution system are designed to offset the entire design load of the volume.
· The floor area of a garage shall be excluded, even if it is conditioned.
· The floor area of a thermally isolated sunroom shall be excluded.
· The floor area of an attic shall be excluded, even if it is Conditioned Space Volume.
· The floor area of a floor cavity shall be excluded, even if it is Conditioned Space Volume.
· The floor area of a crawlspace shall be excluded, even if it is Conditioned Space Volume.
Conditioned Space Volume - The volume within a building serviced by a space heating or cooling system designed to maintain space conditions at 78 °F (26 °C) for cooling and 68 °F (20 °C) for heating. The following specific spaces are addressed to ensure consistent application of this definition:
· If the volume both above and below a floor cavity meets this definition, then the volume of the floor cavity shall also be included. Otherwise the volume of the floor cavity shall be excluded.
· If the volume of one or both of the spaces horizontally adjacent to a wall cavity meets this definition, then the volume of the wall cavity shall also be included. Otherwise, the volume of the wall cavity shall be excluded.
· The volume of a vented attic shall be excluded.
· The volume of a vented crawlspace shall be excluded.
· The volume of a garage shall be excluded, even if it is conditioned.
· The volume of a thermally isolated sunroom shall be excluded.
· The volume of an unvented attic, an unvented crawlspace, or a basement shall only be included if the Rater has obtained a Manual J, S, and D report and verified that both the heating and cooling equipment and distribution system are designed to offset the entire design load of the volume.
Crawl Space-A shallow unfinished space, beneath the first floor or under the roof of a building allowing access to wiring or plumbing.
Infiltration Volume – The sum of the Conditioned Space Volume and Unconditioned Space Volume in the dwelling unit, minus the volume of floor cavities that have Unconditioned Space Volume both above and below, unconditioned wall cavities, vented attics, vented crawlspaces, garages, and thermally isolated sunrooms.
Unconditioned Space Volume - The volume within a building that is not Conditioned Space Volume but which may contain heat sources or sinks that influence the temperature of the area or room. The following specific spaces are addressed to ensure consistent application of this definition:
· The volume of a floor cavity shall be included, unless the volume both above and below the floor cavity meets the definition of Conditioned Space Volume.
· The volume of a wall cavity shall be included, unless the wall cavity meets the definition of Conditioned Space Volume.
· The volume of a vented attic shall be included.
· The volume of a vented crawlspace shall be included.
· The volume of a garage shall be included, even if it is conditioned.
· The volume of a thermally isolated sunroom shall be included.
· The volume of an unvented attic, an unvented crawlspace, or a basement shall be included unless it meets the definition of Conditioned Space Volume.
Comment #30Page Number: There are noneParagraph / Figure / Table / Note: 3.2.10Comment Intent: ObjectionComment Type: TechnicalComment: Chapter 8 has a paragraph: “802.2.11 Un-dampered or fixed-damper intentional openings between conditioned space and the exterior or unconditioned spaces:” that was clearly intended to include combustion air and make up air openings in the enclosure (I was in the meetings and this was specifically discussed and unanimously agreed on). The wording in Standard 380 was changed to “Non-dampered ventilation openings” and the sub paragraphs under this clearly refer to intermittently or continuously operating ventilation systems. It is not at all clear if undampered combustion or make up air openings are part of a ventilation system (I think most people would say they are not) and are covered by this. These are some of the most common undampered intentional holes in a building and it must be clear how to prepare them. The Chapter 8 subcommittee got it right. Proposed Change: Under paragraph 3.2.10 an additional paragraph should be added: 3.2.10.4. All other Non-dampered intentional openings between conditioned space and the exterior or unconditioned spaces shall be left open. For example undampered combustion air or make-up air openings shall be left in their open position. Response: Accept in principle The committee agrees that language needs to be added that instructs the Rater on how to address non-dampered intentional openings, such as those for combustion air or make-up air. As a result, the heading for Section 3.2.11 will be revised to, “3.2.11. Non-dampered openings for ventilation, combustion air, & make-up air” and Section 3.2.11.5 will be added, as follows: “3.2.11.5. All other non-dampered intentional openings (e.g., combustion air inlets, make-up air inlets) between conditioned space and the exterior or unconditioned spaces shall be left open.”
Chapter 8 has a paragraph: “802.2.11 Un-dampered or fixed-damper intentional openings between conditioned space and the exterior or unconditioned spaces:” that was clearly intended to include combustion air and make up air openings in the enclosure (I was in the meetings and this was specifically discussed and unanimously agreed on). The wording in Standard 380 was changed to “Non-dampered ventilation openings” and the sub paragraphs under this clearly refer to intermittently or continuously operating ventilation systems. It is not at all clear if undampered combustion or make up air openings are part of a ventilation system (I think most people would say they are not) and are covered by this. These are some of the most common undampered intentional holes in a building and it must be clear how to prepare them. The Chapter 8 subcommittee got it right.
Under paragraph 3.2.10 an additional paragraph should be added:
3.2.10.4. All other Non-dampered intentional openings between conditioned space and the exterior or unconditioned spaces shall be left open. For example undampered combustion air or make-up air openings shall be left in their open position.
The committee agrees that language needs to be added that instructs the Rater on how to address non-dampered intentional openings, such as those for combustion air or make-up air. As a result, the heading for Section 3.2.11 will be revised to, “3.2.11. Non-dampered openings for ventilation, combustion air, & make-up air” and Section 3.2.11.5 will be added, as follows: “3.2.11.5. All other non-dampered intentional openings (e.g., combustion air inlets, make-up air inlets) between conditioned space and the exterior or unconditioned spaces shall be left open.”
Comment #31Page Number: no page numbersParagraph / Figure / Table / Note: 3.2.2Comment Intent: ObjectionComment Type: TechnicalComment: There should always be an air barrier between a house and an attached garage even if the garage is heated. Because this air barrier is important for health and safety reasons the house should always be tested as if the garage were outside. Maybe it could also be tested by itself as a separate zone or as is described in the current draft, but a test with the garage treated as outside should always be done. Proposed Change: Paragraph 3.2.2. Attached Garages ahould be replaced with the wording in Chapter 8, section 802.2.2 "Attached garages: All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door." Response: Accept
There should always be an air barrier between a house and an attached garage even if the garage is heated. Because this air barrier is important for health and safety reasons the house should always be tested as if the garage were outside. Maybe it could also be tested by itself as a separate zone or as is described in the current draft, but a test with the garage treated as outside should always be done.
Paragraph 3.2.2. Attached Garages ahould be replaced with the wording in Chapter 8, section 802.2.2 "Attached garages: All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door."
Comment #32Page Number: noneParagraph / Figure / Table / Note: 3.4.1.2Comment Intent: ObjectionComment Type: GeneralComment:Proposed Change: The induced enclosure pressure difference is defined as the induced enclosure pressure minus the baseline. This is wrong. There should be a definition correctly defining the induced enclosure pressure difference as the measured enclosure pressure difference with the air moving fan on minus the pre test baseline enclosure pressure difference. Response: Reject The standard already uses the induced enclosure pressure difference as defined by the commenter.
The induced enclosure pressure difference is defined as the induced enclosure pressure minus the baseline. This is wrong. There should be a definition correctly defining the induced enclosure pressure difference as the measured enclosure pressure difference with the air moving fan on minus the pre test baseline enclosure pressure difference.
The standard already uses the induced enclosure pressure difference as defined by the commenter.
Comment #33Page Number: noneParagraph / Figure / Table / Note: 3.4.1.5Comment Intent: Not an ObjectionComment Type: TechnicalComment:Proposed Change: A manufacturer's temperature correction should be permitted if "it is done using tables 1a and 1b or according to the equations in ASTM E779-10. Response: Accept
A manufacturer's temperature correction should be permitted if "it is done using tables 1a and 1b or according to the equations in ASTM E779-10.
Comment #34Page Number: noneParagraph / Figure / Table / Note: 3.4.2.2Comment Intent: ObjectionComment Type: TechnicalComment:Proposed Change: Same mistake in definition as in 3.4.1.2 Response: Reject The standard already uses the induced enclosure pressure difference as defined by the commenter.
Same mistake in definition as in 3.4.1.2
Comment #35Page Number: noneParagraph / Figure / Table / Note: 3.4.2.2Comment Intent: ObjectionComment Type: TechnicalComment:Proposed Change: Measuring the temperature once at the beginning of the test seems adequate to me. It was already measured in 3.3.3 and wouldn't have to be measured again. Calculations aren't very sensitive to temperature and it usually doesn't change much during a test. Response: Reject The temperature may change over the duration of a multi-point test, particularly when testing in hot or cold weather. The recording of multiple temperatures only requires a little more effort than recording a single temperature, or temperatures at the beginning and end as required in E779. Section 3.3.3 is a section on general procedure set-yup, it is not an instruction to record the temperature.
Measuring the temperature once at the beginning of the test seems adequate to me. It was already measured in 3.3.3 and wouldn't have to be measured again. Calculations aren't very sensitive to temperature and it usually doesn't change much during a test.
The temperature may change over the duration of a multi-point test, particularly when testing in hot or cold weather. The recording of multiple temperatures only requires a little more effort than recording a single temperature, or temperatures at the beginning and end as required in E779. Section 3.3.3 is a section on general procedure set-yup, it is not an instruction to record the temperature.
Comment #36Page Number: noneParagraph / Figure / Table / Note: 4.1.2Comment Intent: ObjectionComment Type: TechnicalComment: Same as for 3.1.2 Proposed Change: Same comment as for 3.1.2 Response: Accept
Same as for 3.1.2
Same comment as for 3.1.2
Comment #37Page Number: noneParagraph / Figure / Table / Note: 4.2.7Comment Intent: Not an ObjectionComment Type: TechnicalComment: What is meant by sealing at "both the face and perimeter"? Does this mean you must seal to both the face of the perimeter of the grille as well as to the sheetrock around the grille. This would mean that leaks between the boot and the sheetrock would count as leaks, which I agree with. But then in the next 2 sentences you can remove a regester or leave a register off and seal to the boot, which means that leaks betwee boots and surrounding plywood or sheetrock don't count as leaks. This seems inconsistent or at least not clear. Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, however, the respondent is correct in his interpretation of the standard: Registers atop carpets are permitted to be removed and the face of the duct boot temporarily sealed during testing. The rationale for this allowance is that Raters have reported great difficulty in sealing the perimeter of registers atop carpets. As a result, the measured duct leakage for the system is higher, even though the air leaking around the register perimeter through the carpet is entering the intended room. Anecdotally, about 5-15 CFM of leakage per register can occur at this location. For a home with multiple registers atop carpets, this can significantly change the test results. For homes without registers and grilles present, the face of the duct boots shall be sealed instead. Without this allowance, Raters that entered a new home with no registers would be required to obtain and install registers in order to complete a HERS rating, or postpone the rating until a later date after registers had been installed. In addition, Raters would not be permitted to use duct leakage results obtained at ‘rough-in’ for a HERS rating. While sealing at the duct boots may result in underestimating leakage relative to sealing at the register, codes or programs can address this concern through added requirements (e.g., the ENERGY STAR certified homes program requires that duct boots be sealed to the subfloor and visually inspected if duct testing is done without registers in place).
What is meant by sealing at "both the face and perimeter"? Does this mean you must seal to both the face of the perimeter of the grille as well as to the sheetrock around the grille. This would mean that leaks between the boot and the sheetrock would count as leaks, which I agree with. But then in the next 2 sentences you can remove a regester or leave a register off and seal to the boot, which means that leaks betwee boots and surrounding plywood or sheetrock don't count as leaks. This seems inconsistent or at least not clear.
The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, however, the respondent is correct in his interpretation of the standard:
While sealing at the duct boots may result in underestimating leakage relative to sealing at the register, codes or programs can address this concern through added requirements (e.g., the ENERGY STAR certified homes program requires that duct boots be sealed to the subfloor and visually inspected if duct testing is done without registers in place).
Comment #38Page Number: no page numbersParagraph / Figure / Table / Note: 4.3Comment Intent: Not an ObjectionComment Type: TechnicalComment: I think the committee should consider adding a second exception that would allow either method if the total duct leakage is less than 50 cfm. When total leakage is small the flows during the test are small and pressures in the duct system are very uniform. Maybe this should be stated as a % of rated flow so it would also apply to small ventilation system ducts. Response: Accept in Principle Added second exception: Exception 2: If the total duct leakage is less than 50 cfm (25 L/s) then either method may be used.
I think the committee should consider adding a second exception that would allow either method if the total duct leakage is less than 50 cfm. When total leakage is small the flows during the test are small and pressures in the duct system are very uniform. Maybe this should be stated as a % of rated flow so it would also apply to small ventilation system ducts.
Added second exception:
Exception 2: If the total duct leakage is less than 50 cfm (25 L/s) then either method may be used.
Comment #39Page Number: no page numbersParagraph / Figure / Table / Note: 4.3.2.4Comment Intent: Not an ObjectionComment Type: TechnicalComment: One place that is allowed to place the second probe is the grille closest to the air handler. But for method 1 this is the grille that the fan is installed in. I think this should say "the closest return grille to the air handler unless this is where the duct tester is installed, in which case the second closest retrun grille to the air handler shall be used." Response: Accept
One place that is allowed to place the second probe is the grille closest to the air handler. But for method 1 this is the grille that the fan is installed in. I think this should say "the closest return grille to the air handler unless this is where the duct tester is installed, in which case the second closest retrun grille to the air handler shall be used."
Comment #40Page Number: no page numbersParagraph / Figure / Table / Note: 4.3.3.Comment Intent: Not an ObjectionComment Type: TechnicalComment: If the intent of the multiple pressure probes is to get a pressure that is close to the mean, then it should be specified to use equal length (or better, equal resistance) tubes from the probes to the tee. Response: Reject The comment does not give a technical reason for equal length tubing. Equal length tubing has been specified in other test methods, e.g., measuring building exterior pressures, but this is for reasons associated with time-varying pressure signals due to wind that are not present in the steady-state testing in the this test.
If the intent of the multiple pressure probes is to get a pressure that is close to the mean, then it should be specified to use equal length (or better, equal resistance) tubes from the probes to the tee.
The comment does not give a technical reason for equal length tubing. Equal length tubing has been specified in other test methods, e.g., measuring building exterior pressures, but this is for reasons associated with time-varying pressure signals due to wind that are not present in the steady-state testing in the this test.
Comment #41Page Number: no page numbersParagraph / Figure / Table / Note: 4.4.2.1Comment Intent: ObjectionComment Type: TechnicalComment: When measuring duct leakage to outside it seems to me that spaces containing ducts that are outside the pressure boundary such as garages, attics, and crawlspaces should be open to outside as much as practicle. There may be very large holes between the house and these spaces which would cause them to be at close to the same pressure as the house during the test. This would largely negate any leakage between the ducts and that space. But during normal operating conditions the pressure in those spaces is typiclly not affected much by the duct leakage and the ducts leak into those spaces. This leakage is unintentional and undesired and at least in many cases almost a 100% energy loss. To not count this leakage is a mistake. Response: Accept in Principle Although the respondent does not propose a specific change to the standard, the comment has some technical merit and would be consistent with draft Chapter 8 of the RESNET standards. Therefore the following change will be made: If ducts run through unconditioned spaces such as attics, garages or crawlspaces, any vents, access panels, doors, or windows between those spaces and the outside shall be opened.
When measuring duct leakage to outside it seems to me that spaces containing ducts that are outside the pressure boundary such as garages, attics, and crawlspaces should be open to outside as much as practicle. There may be very large holes between the house and these spaces which would cause them to be at close to the same pressure as the house during the test. This would largely negate any leakage between the ducts and that space. But during normal operating conditions the pressure in those spaces is typiclly not affected much by the duct leakage and the ducts leak into those spaces. This leakage is unintentional and undesired and at least in many cases almost a 100% energy loss. To not count this leakage is a mistake.
Although the respondent does not propose a specific change to the standard, the comment has some technical merit and would be consistent with draft Chapter 8 of the RESNET standards. Therefore the following change will be made:
If ducts run through unconditioned spaces such as attics, garages or crawlspaces, any vents, access panels, doors, or windows between those spaces and the outside shall be opened.
Comment #42Page Number: no page numbersParagraph / Figure / Table / Note: 3.1Comment Intent: Not an ObjectionComment Type: GeneralComment: Something should be said about calibration and recalibration of instruments. I suggest starting with Chapter 8, section 803.9. I think there should be a statement that , at a minimum, manufacturers' recommendations should be followed. However, this may not be enough. One manufacturer recommends calibration of their manometer every 5 years but doesn't have enough experience with this new product to know that this will be adequate. The sensor manufacturer doesn't have specs on long term drift that support this. This same manufacturer ships calibration certificates that show data points that are out of spec with their own specifications. So you can't always trust manufacturers information. Response: Accept The committee agrees that equipment must be tested annual for calibration to help ensure accurate measurements. The following language has been added to each section that defines the equipment to be used for the procedure: “The equipment below shall be tested at least annually for calibration using the manufacturer’s calibration procedure.”
Something should be said about calibration and recalibration of instruments. I suggest starting with Chapter 8, section 803.9. I think there should be a statement that , at a minimum, manufacturers' recommendations should be followed. However, this may not be enough. One manufacturer recommends calibration of their manometer every 5 years but doesn't have enough experience with this new product to know that this will be adequate. The sensor manufacturer doesn't have specs on long term drift that support this. This same manufacturer ships calibration certificates that show data points that are out of spec with their own specifications. So you can't always trust manufacturers information.
The committee agrees that equipment must be tested annual for calibration to help ensure accurate measurements. The following language has been added to each section that defines the equipment to be used for the procedure:
“The equipment below shall be tested at least annually for calibration using the manufacturer’s calibration procedure.”
Comment #43Page Number: 16Paragraph / Figure / Table / Note: Section 5, paragraph 1Comment Intent: ObjectionComment Type: GeneralComment: The first paragraph in Section 5 contains a parenthetical phrase that is intended to list types of whole-house ventilation systems. ASHRAE 62.2 and the IRC approve supply systems, exhaust systems, and combinations thereof for this purpose. The parenthetical phrase should be expanded to include these systems to avoid confusion. Proposed Change: ...(e.g., ventilation inlet on the return side an outdoor air duct connected to the return trunk of an HVAC system, an in-line supply fan, an exhaust fan, an HRV, or an ERV)... Response: Accept
The first paragraph in Section 5 contains a parenthetical phrase that is intended to list types of whole-house ventilation systems. ASHRAE 62.2 and the IRC approve supply systems, exhaust systems, and combinations thereof for this purpose. The parenthetical phrase should be expanded to include these systems to avoid confusion.
...(e.g., ventilation inlet on the return side an outdoor air duct connected to the return trunk of an HVAC system, an in-line supply fan, an exhaust fan, an HRV, or an ERV)...
Comment #44Page Number: 16Paragraph / Figure / Table / Note: Section 5, paragraph 2Comment Intent: ObjectionComment Type: GeneralComment: The following phrase in the second paragraph of Section 5 is confusing: "Airflow measurements shall be verified to be in the acceptable range of airflow specified by the manufacturer for the equipment being used." Manufacturers typically list rated airflows, with the caveat that field conditions like duct losses can reduce these. However, manufacturers do not typically list "acceptable ranges of airflow". Please delete this sentence, which is confusing. Proposed Change: Airflow measurements shall be verified to be in the acceptable range of airflow specified by the manufacturer for the equipment being used. Response: Accept
The following phrase in the second paragraph of Section 5 is confusing: "Airflow measurements shall be verified to be in the acceptable range of airflow specified by the manufacturer for the equipment being used." Manufacturers typically list rated airflows, with the caveat that field conditions like duct losses can reduce these. However, manufacturers do not typically list "acceptable ranges of airflow". Please delete this sentence, which is confusing.
Comment #45Page Number: 16Paragraph / Figure / Table / Note: Section 5, Informative FootnoteComment Intent: ObjectionComment Type: GeneralComment: Section 5: The informative footnote is misleading. ASHRAE 62.2, the 2012/2015 IRC, and the 2015 IMC approve both continuously and intermittently operated whole-house mechanical ventilation exhaust systems in detached and attached dwelling units. This is regardless of whether or not there is a supply ventilation system for an adjacent corridor. To verify the whole-house mechanical flow rate of this system for each dwelling unit, the HERS rater need only measure the flow rate of the component of the WHMV system in each dwelling unit (i.e., the exhaust fan flow rate). Proposed Change: 1 Informative Note: Measuring the ventilation air supplied to corridors of multifamily buildings is beyond the scope of this standard. However, measuring the flow rate of exhaust systems used for whole house mechanical ventilation in individual dwelling units is within the scope of this standard. A multifamily building that has ventilation air supplied to corridors for the purpose of fresh air distribution to dwelling units does not have a ventilation system separate from other dwelling units, even if each dwelling has individual continuous exhaust ventilation. Although measurement of the individual dwelling exhaust could be considered within the scope of this standard, the overall ventilation system for each dwelling includes the central corridor supply system, and is thus outside the scope of this standard. Response: Accept
Section 5: The informative footnote is misleading. ASHRAE 62.2, the 2012/2015 IRC, and the 2015 IMC approve both continuously and intermittently operated whole-house mechanical ventilation exhaust systems in detached and attached dwelling units. This is regardless of whether or not there is a supply ventilation system for an adjacent corridor. To verify the whole-house mechanical flow rate of this system for each dwelling unit, the HERS rater need only measure the flow rate of the component of the WHMV system in each dwelling unit (i.e., the exhaust fan flow rate).
1 Informative Note: Measuring the ventilation air supplied to corridors of multifamily buildings is beyond the scope of this standard. However, measuring the flow rate of exhaust systems used for whole house mechanical ventilation in individual dwelling units is within the scope of this standard.
A multifamily building that has ventilation air supplied to corridors for the purpose of fresh air distribution to dwelling units does not have a ventilation system separate from other dwelling units, even if each dwelling has individual continuous exhaust ventilation. Although measurement of the individual dwelling exhaust could be considered within the scope of this standard, the overall ventilation system for each dwelling includes the central corridor supply system, and is thus outside the scope of this standard.
Comment #46Page Number: 18Paragraph / Figure / Table / Note: 5.1.2.2.2Comment Intent: ObjectionComment Type: GeneralComment: The Energy Conservatory says that a differential pressure range between 1.0 Pa and 8.0 Pa (between the flow capture element and the room) is acceptable when using their Exhaust Fan Flow Meter (see p6 of the Exhaust Fan Flow Meter Operation Manual, here: http://www.energyconservatory.com/sites/default/files/documents/flow_box_manual_dg-700.pdf). Why not use this range to provide greater flexibility for the HERS rater? Proposed Change: 5.1.2.2.2. The opening area of the Airflow Resistance Device shall be adjusted until, using the Manometer, the pressure difference between the flow capture element and the room is between 1 and 5 8 Pa. Response: Accept
The Energy Conservatory says that a differential pressure range between 1.0 Pa and 8.0 Pa (between the flow capture element and the room) is acceptable when using their Exhaust Fan Flow Meter (see p6 of the Exhaust Fan Flow Meter Operation Manual, here: http://www.energyconservatory.com/sites/default/files/documents/flow_box_manual_dg-700.pdf). Why not use this range to provide greater flexibility for the HERS rater?
Comment #47Page Number: 18Paragraph / Figure / Table / Note: 5.1.2.3Comment Intent: ObjectionComment Type: GeneralComment: Why couldn’t the airflow resistance device be used to test a multi-port exhaust system? Simply measure the flow at each exhaust port and then sum these flows to get the total flow of the system. Not permitting these devices to be used could greatly increase the expense and difficulty associated with measuring the flow of multi-port exhaust systems. Suggest that this section be deleted or amended to permit the use of airflow resistance devices with multi-port exhaust systems. Proposed Change: 5.1.2.3. Limitations of Procedure. An Airflow Resistance Device is only permitted to be used on mechanical ventilation systems that do not have multiple duct branches. Response: Reject With multi-port systems the added air flow resistance can substantially change the air flow in the branch being measured. This bias is repeated for each branch, thus resulting in and undermeasurement of the total system air flow.
Why couldn’t the airflow resistance device be used to test a multi-port exhaust system? Simply measure the flow at each exhaust port and then sum these flows to get the total flow of the system. Not permitting these devices to be used could greatly increase the expense and difficulty associated with measuring the flow of multi-port exhaust systems. Suggest that this section be deleted or amended to permit the use of airflow resistance devices with multi-port exhaust systems.
With multi-port systems the added air flow resistance can substantially change the air flow in the branch being measured. This bias is repeated for each branch, thus resulting in and undermeasurement of the total system air flow.
Comment #48Page Number: 9 of 21Paragraph / Figure / Table / Note: 3.5.2Comment Intent: ObjectionComment Type: GeneralComment: Massachusetts will adopt the IECC 2012 on 7/1/14 and blower door tests will be mandatory. The code requirement change from 2009 to 2012 will drop the ACH50 threshold from 7.0 ACH50 to 3.0 ACH50. Failure to achieve this threshold will result in buildings not receiving occupancy permits.This change by itself will be a challenge for most builders. This provision makes any compliance threshold 22% more stringent, even when tested under conditions (low wind, tight building shell) that provide high confidence in the blower door test result. Either eliminate this provision and replace it with the current language from the Mortgage industry standard Chapter 8, or at least allow the continued use of the existing Chapter 8 approach as an alternate”. Proposed Change: Either eliminate Section 3.5.2 and replace it with the current language from the Mortgage industry standard Chapter 8, or at least allow the continued use of the existing Chapter 8 approach as an alternate”. Response: Accept in principle The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
Massachusetts will adopt the IECC 2012 on 7/1/14 and blower door tests will be mandatory. The code requirement change from 2009 to 2012 will drop the ACH50 threshold from 7.0 ACH50 to 3.0 ACH50. Failure to achieve this threshold will result in buildings not receiving occupancy permits.This change by itself will be a challenge for most builders. This provision makes any compliance threshold 22% more stringent, even when tested under conditions (low wind, tight building shell) that provide high confidence in the blower door test result. Either eliminate this provision and replace it with the current language from the Mortgage industry standard Chapter 8, or at least allow the continued use of the existing Chapter 8 approach as an alternate”.
Either eliminate Section 3.5.2 and replace it with the current language from the Mortgage industry standard Chapter 8, or at least allow the continued use of the existing Chapter 8 approach as an alternate”.
Comment #49Page Number: 11 of 21Paragraph / Figure / Table / Note: 4.2.4Comment Intent: ObjectionComment Type: TechnicalComment: Removing the filter removes a plug, albeit a loose plug, in a very large hole. This will result in an exaggerated level of measured leakage. Proposed Change: 4.2.4 All filters in the duct system and air handler cabinet shall be removed. If the Duct Leakage Tester is installed at the retrun grille, any filters present at that grille shall also be removed. If present, filter slot cover(s) shall be replaced after removing filters. If no filter cover is present seal the opening for the test and recommend or specify a filter slot cover. Response: Reject Any filter slot leakage under normal operating conditions should be included in the testing. Therefore we cannot seal this opening during testing.
Removing the filter removes a plug, albeit a loose plug, in a very large hole. This will result in an exaggerated level of measured leakage.
4.2.4 All filters in the duct system and air handler cabinet shall be removed. If the Duct Leakage Tester is installed at the retrun grille, any filters present at that grille shall also be removed. If present, filter slot cover(s) shall be replaced after removing filters. If no filter cover is present seal the opening for the test and recommend or specify a filter slot cover.
Any filter slot leakage under normal operating conditions should be included in the testing. Therefore we cannot seal this opening during testing.
Comment #50Page Number: 13 of 21Paragraph / Figure / Table / Note: 4.3.2Comment Intent: Not an ObjectionComment Type: GeneralComment: The standard should specify whether a static pressure probe or a straight piece of tubing should be used based on probe location. Response: Accept in principle The text has been changed to require a static pressure probe.
The standard should specify whether a static pressure probe or a straight piece of tubing should be used based on probe location.
The text has been changed to require a static pressure probe.
Comment #51Page Number: 16 of 21Paragraph / Figure / Table / Note: 5Comment Intent: Not an ObjectionComment Type: EditorialComment: If it is necessary to adjust the air flow for a BD test for temperature and altitude, why are these airflows not being similarly modified? Response: Reject The respondent does not propose a specific change to the standard, therefore the comment is rejected. For context, BD test corrections are used because of the temperature differences between the induced flow in the blower and the air flowing through the envelope. These pressure differences do not occur in mechanical ventilation system flow measurements. The altitude correction for the BD results is used because the software using the envelope leakage results uses this same altitude correction.
If it is necessary to adjust the air flow for a BD test for temperature and altitude, why are these airflows not being similarly modified?
For context, BD test corrections are used because of the temperature differences between the induced flow in the blower and the air flowing through the envelope. These pressure differences do not occur in mechanical ventilation system flow measurements. The altitude correction for the BD results is used because the software using the envelope leakage results uses this same altitude correction.
Comment #52Page Number: 17-20 of 21Paragraph / Figure / Table / Note: 5.1.1,5.1.2, 5.1.3Comment Intent: Not an ObjectionComment Type: TechnicalComment: According to the air flow measuring devices section of this standard, pitot tubes, hot wire anemometers and vane anemometers are not approved equipment. A skilled user of this equipment can accurately measure air flow. What is the rationale for excluding these pieces of equipment. Proposed Change: Add these equipment types to the approved list of airflow meauring devices Response: Reject This equipment does not have the required accuracy for this type of testing, and/or requires access to ducting and necessity of long straight ducts that makes them highly impractical for residential applications.
According to the air flow measuring devices section of this standard, pitot tubes, hot wire anemometers and vane anemometers are not approved equipment. A skilled user of this equipment can accurately measure air flow. What is the rationale for excluding these pieces of equipment.
Add these equipment types to the approved list of airflow meauring devices
This equipment does not have the required accuracy for this type of testing, and/or requires access to ducting and necessity of long straight ducts that makes them highly impractical for residential applications.
Comment #53Page Number: 20Paragraph / Figure / Table / Note: 5.3.1.1Comment Intent: ObjectionComment Type: GeneralComment: Section 5 should be expanded to include integrated diagnostic tools that are supplied by the manufacturer with ventilation equipment. These are common for HRVs and ERVs. The two following cases are suggested: Equipment with integrated pressure taps: the accuracy should be verified by the manufacturer to be within +/-10% at the high speed setting, and Equipment with complete on-board flow diagnostics (e.g., a device to monitor pressure or fan watt draw and a display of the corresponding flow rate), that the accuracy should be verified by the manufacturer to be +/-15% of the flow at high speed setting The +/-15% accuracy for the complete on-board diagnostics would be comparable to the combined accuracy of +/-10% for an airflow measurement station and +/-5% for a manometer. Response: Accept in principle Added new option in Section 5.3 to use an Integrated Diagnostic Tool to measure the ventilation airflow mid-stream. For simplicity, and to encourage the development and use of such tools, a single tolerance of ±15% was specified for this new option. Specifically, Section 5.3.2 was added, as follows: 5.3.2. Integrated Diagnostic Tool 5.3.2.1. Equipment Needed 5.3.2.1.1. Integrated Diagnostic Tool. A tool that is integrated into the ventilation equipment (e.g., pressure taps, a device that measures a parameter such as watt draw that can be translated to airflow) that permits assessment of airflow with a manufacturer-reported accuracy equal to or better than ±15% of the measured flow at the highest speed setting of the ventilation equipment. 5.3.2.2. Procedure to Conduct Airflow Test. Follow the manufacturer-provided instructions for the Integrated Diagnostic Tool to determine the airflow.
Section 5 should be expanded to include integrated diagnostic tools that are supplied by the manufacturer with ventilation equipment. These are common for HRVs and ERVs. The two following cases are suggested:
The +/-15% accuracy for the complete on-board diagnostics would be comparable to the combined accuracy of +/-10% for an airflow measurement station and +/-5% for a manometer.
Added new option in Section 5.3 to use an Integrated Diagnostic Tool to measure the ventilation airflow mid-stream. For simplicity, and to encourage the development and use of such tools, a single tolerance of ±15% was specified for this new option. Specifically, Section 5.3.2 was added, as follows:
5.3.2. Integrated Diagnostic Tool
5.3.2.1. Equipment Needed
5.3.2.1.1. Integrated Diagnostic Tool. A tool that is integrated into the ventilation equipment (e.g., pressure taps, a device that measures a parameter such as watt draw that can be translated to airflow) that permits assessment of airflow with a manufacturer-reported accuracy equal to or better than ±15% of the measured flow at the highest speed setting of the ventilation equipment.
5.3.2.2. Procedure to Conduct Airflow Test. Follow the manufacturer-provided instructions for the Integrated Diagnostic Tool to determine the airflow.
Comment #54Page Number: 9Paragraph / Figure / Table / Note: 3.4.2.5Comment Intent: Not an ObjectionComment Type: TechnicalComment: The allowable calculation method for corrected airflow values is unclear. This section currently does not state whether auto-calculation methods are permissible. Proposed Change: The corrected airflow (Q) and the induced enclosure pressure difference measured at each pressure station (dP) shall be used in a log-linearized regression of the form Q=C(dP)n(e.g., using the procedures in ASTM E779-10, Section 9 and Annex A.1) to calculate C and n. Alternatively, the Rater shall use software (e.g., from the Blower Door manufacturer) that automatically calculates C and n in accordance with the referenced ASTM standard). Response: Accept in principle Suggestion added as a footnote.
The allowable calculation method for corrected airflow values is unclear. This section currently does not state whether auto-calculation methods are permissible.
The corrected airflow (Q) and the induced enclosure pressure difference measured at each pressure station (dP) shall be used in a log-linearized regression of the form Q=C(dP)n(e.g., using the procedures in ASTM E779-10, Section 9 and Annex A.1) to calculate C and n. Alternatively, the Rater shall use software (e.g., from the Blower Door manufacturer) that automatically calculates C and n in accordance with the referenced ASTM standard).
Suggestion added as a footnote.
Comment #55Page Number: 1Paragraph / Figure / Table / Note: 3.1.1Comment Intent: Not an ObjectionComment Type: EditorialComment: The language “..achieve a range of pressure differences..” is vague. Consider clarifying the definition to better state the purpose of the Air-Moving Fan. Proposed Change: Air-Moving Fan. A fan that is capable of moving air into or out of the building to achieve a range of pressure differences to achieve one or more target pressure differences between the dwelling unit and the exterior. Response: Accept
The language “..achieve a range of pressure differences..” is vague. Consider clarifying the definition to better state the purpose of the Air-Moving Fan.
Air-Moving Fan. A fan that is capable of moving air into or out of the building to achieve a range of pressure differences to achieve one or more target pressure differences between the dwelling unit and the exterior.
Comment #56Page Number: 2Paragraph / Figure / Table / Note: 3.2Comment Intent: ObjectionComment Type: GeneralComment: The guidance “any abnormal conditions shall be recorded on the test report” is ambiguous as it implies that if one or more of the steps listed under Section 3.2 are not able to be completed, the testing procedure can still be performed as long as it is noted. Proposed Change: 3.2. Procedure to Prepare the Building for Testing Any abnormal conditions shall be recorded on the test report. Response: Accept
The guidance “any abnormal conditions shall be recorded on the test report” is ambiguous as it implies that if one or more of the steps listed under Section 3.2 are not able to be completed, the testing procedure can still be performed as long as it is noted.
3.2. Procedure to Prepare the Building for Testing
Any abnormal conditions shall be recorded on the test report.
Comment #57Page Number: 5Paragraph / Figure / Table / Note: 3.4.1.5Comment Intent: Not an ObjectionComment Type: GeneralComment: Please provide a reference for the source of the calculation and implementation of the Altitude Correction Factor. The similar factor, the Temperature Correction Factor, includes a reference to ASTM E779-10. Please provide an equivalent reference for the Altitude Correction Factor within the standard. Proposed Change: N/A Response: Reject This is std engineering HVAC calculation – here is an on-line reference: http://www.engineeringtoolbox.com/air-altitude-density-volume-d_195.html However, looking at this site indicates an error in the draft standard. The ACF should be 1+0.00006x feet and 1+0.00002x meters. These changes have been made o the draft.
Please provide a reference for the source of the calculation and implementation of the Altitude Correction Factor. The similar factor, the Temperature Correction Factor, includes a reference to ASTM E779-10. Please provide an equivalent reference for the Altitude Correction Factor within the standard.
N/A
This is std engineering HVAC calculation – here is an on-line reference: http://www.engineeringtoolbox.com/air-altitude-density-volume-d_195.html
However, looking at this site indicates an error in the draft standard. The ACF should be 1+0.00006x feet and 1+0.00002x meters. These changes have been made o the draft.
Comment #58Page Number: 10Paragraph / Figure / Table / Note: Equation 7aComment Intent: Not an ObjectionComment Type: EditorialComment: Formatting related to Equation 7a contains an error as it is offset from equation 7b. Please align the equations so that the first letter of each is aligned vertically. Proposed Change: N/A Response: Accept
Formatting related to Equation 7a contains an error as it is offset from equation 7b. Please align the equations so that the first letter of each is aligned vertically.
Comment #59Page Number: 10Paragraph / Figure / Table / Note: 4Comment Intent: Not an ObjectionComment Type: EditorialComment: The final sentence contained in Section 4 that specifies which ducts are required to undergo air leakage testing is unclear. Minor changes to improve clarity are included in this proposed change. Proposed Change: For multifamily buildings where each unit has its own duct system, each unit shall be tested individually. The leakage to outside test shall be performed using a Blower Door in the main entry to the unit to pressurize the individual unit with reference to outside. If the main entry door is in an interior hallway then the hallway shall be well connected to outside through open windows or doors, or an exterior window or door (such as to deck or patio) shall be used. Only the ducts in the dwelling unit under being tested shall be included in the air leakage test. are tested. Response: Accept
The final sentence contained in Section 4 that specifies which ducts are required to undergo air leakage testing is unclear. Minor changes to improve clarity are included in this proposed change.
For multifamily buildings where each unit has its own duct system, each unit shall be tested individually. The leakage to outside test shall be performed using a Blower Door in the main entry to the unit to pressurize the individual unit with reference to outside. If the main entry door is in an interior hallway then the hallway shall be well connected to outside through open windows or doors, or an exterior window or door (such as to deck or patio) shall be used. Only the ducts in the dwelling unit under being tested shall be included in the air leakage test. are tested.
Comment #60Page Number: 9Paragraph / Figure / Table / Note: 3.5.2Comment Intent: ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. We do not understand the logic of correcting leakage rates in this manner. There is not justification given for why a factor is applied or why the factor should be larger for a 1 point test. This places an additional burden on Raters and Builders. We think that this is a needless fudge factor that perhaps assures compliance, but is a 22% correction or adjustment really necessary? Proposed Change: Consider a smaller correction factor or no factor at all if no justification for one. Response: Accept in principle The committee has revised the correction factors for envelope leakage testing in the draft standard. There will be no correction factor for multi-point tests as these are currently the best tests that can be performed. The adjustment for single point testing will be retained but reduced to only account for the difference between multi-point and single-point testing. The resulting correction factor is 1.1. The values used in the first public review draft (and the difference between single and multi-point testing in the new draft) are based on uncertainty analysis of many thousands of blower door tests to account for uncertainties in predicting natural infiltration air flows (and resulting energy impacts) based on single and multipoint envelope leakage testing. The uncertainties are a combination of weather induced fluctuations in the measurements and extrapolation errors to convert from measurement conditions (e.g., at 50 Pa) to operating conditions for the home (4 Pa, or less). The analysis is summarized in: Walker, I.S., Sherman, M.H., Joh, J. and Chan, W.R. (2013). Applying Large Datasets to Developing a Better Understanding of Air Leakage Measurement in Homes. International Journal of Ventilation, Vol. 11, No. 4, pp. 323-338. March 2013.
NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware.
We do not understand the logic of correcting leakage rates in this manner. There is not justification given for why a factor is applied or why the factor should be larger for a 1 point test.
Consider a smaller correction factor or no factor at all if no justification for one.
Comment #61Page Number: 11Paragraph / Figure / Table / Note: 4.2Comment Intent: Not an ObjectionComment Type: GeneralComment: Several items under 4.2 imply that the air handler is required to be installed at the time of duct leakage testing, yet this is not explicitly stated. Add a new sub-section under 4.2 that requires that the air handler be installed prior to running the duct leakage tests to address ratings done in new homes. Subsequent items can remain, but their section numbers will need to be shifted. Proposed Change: 4.2.1. The presence of the air handler shall be verified, such that leakage from the air handler will be captured when the test is conducted. If the air handler has not yet been installed (e.g., a new home), then the test shall not be conducted. [Adjust subsequent section numbers] Response: Accept in principle The committee agrees that Section 4.2.1 should be added to clarify that air handlers must be in place during the duct leakage test. In addition, the committee believes that it should be clarified that all other HVAC components must also be in place prior to the test. Therefore, a new Section 4.2.1 will be added and all subsequent sections will be renumbered accordingly. The new Section 4.2.1 will read as follows: “The presence of all components that are included in the HVAC design for the rated home (e.g., heating, cooling, ventilation, dehumidification, humidification, and filtration components) and integrated with the duct system shall be verified, such that leakage from these components will be captured when the test is conducted. If these components have not yet been installed (e.g., an air handler has not yet been installed a new home), then the test shall not be conducted.
Several items under 4.2 imply that the air handler is required to be installed at the time of duct leakage testing, yet this is not explicitly stated. Add a new sub-section under 4.2 that requires that the air handler be installed prior to running the duct leakage tests to address ratings done in new homes. Subsequent items can remain, but their section numbers will need to be shifted.
4.2.1. The presence of the air handler shall be verified, such that leakage from the air handler will be captured when the test is conducted. If the air handler has not yet been installed (e.g., a new home), then the test shall not be conducted.
[Adjust subsequent section numbers]
The committee agrees that Section 4.2.1 should be added to clarify that air handlers must be in place during the duct leakage test. In addition, the committee believes that it should be clarified that all other HVAC components must also be in place prior to the test. Therefore, a new Section 4.2.1 will be added and all subsequent sections will be renumbered accordingly.
The new Section 4.2.1 will read as follows: “The presence of all components that are included in the HVAC design for the rated home (e.g., heating, cooling, ventilation, dehumidification, humidification, and filtration components) and integrated with the duct system shall be verified, such that leakage from these components will be captured when the test is conducted. If these components have not yet been installed (e.g., an air handler has not yet been installed a new home), then the test shall not be conducted.
Comment #62Page Number: 13Paragraph / Figure / Table / Note: 4.4.1.1Comment Intent: Not an ObjectionComment Type: EditorialComment: The current list of unconditioned areas that ducts might run through, and the subsequent requirement to open components, should be revised to improve clarity. Proposed Change: If ducts run through unconditioned spaces such as attics, garages or crawlspaces, then any vents, access panels, doors, or windows between those spaces and the outside shall be opened. Response: Accept
The current list of unconditioned areas that ducts might run through, and the subsequent requirement to open components, should be revised to improve clarity.
If ducts run through unconditioned spaces such as attics, garages or crawlspaces, then any vents, access panels, doors, or windows between those spaces and the outside shall be opened.
Comment #63Page Number: 2Paragraph / Figure / Table / Note: 3.1.5Comment Intent: Not an ObjectionComment Type: GeneralComment: Definition of a Blower Door is incomplete. The description does not include the assembly that is designed to block air flow through the fenestration opening around the Air-Moving Fan and Airflow Meter. Proposed Change: 3.1.5. Blower Door. A device that combines an Air-Moving Fan as defined in Section 3.1.1,and an Airflow Meter as defined in Section 3.1.3, and a mount consisting of a frame and flexible panel that covers the building opening. Response: Accept in principle The committee agrees that definition for Blower Door should include a reference to the covering that integrates the Air-Moving Fan into the building opening, but notes that this cover will not always be a mount consisting of a frame and flexible panel, as the respondent suggests. Therefore, the definition will be revised as follows: “Blower Door. A device that combines an Air-Moving Fan as defined in Section 3.1.1, an Airflow Meter as defined in Section 3.1.3, and a covering to integrate the Air-Moving Fan into the building opening.”
Definition of a Blower Door is incomplete. The description does not include the assembly that is designed to block air flow through the fenestration opening around the Air-Moving Fan and Airflow Meter.
3.1.5. Blower Door. A device that combines an Air-Moving Fan as defined in Section 3.1.1,and an Airflow Meter as defined in Section 3.1.3, and a mount consisting of a frame and flexible panel that covers the building opening.
The committee agrees that definition for Blower Door should include a reference to the covering that integrates the Air-Moving Fan into the building opening, but notes that this cover will not always be a mount consisting of a frame and flexible panel, as the respondent suggests. Therefore, the definition will be revised as follows: “Blower Door. A device that combines an Air-Moving Fan as defined in Section 3.1.1, an Airflow Meter as defined in Section 3.1.3, and a covering to integrate the Air-Moving Fan into the building opening.”
Comment #64Page Number: 11Paragraph / Figure / Table / Note: 4.2.4Comment Intent: ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. If there is no filter cover exists, removing the filter without installing a temporary removes a plug, albeit a loose plug, in a very large hole. This will result in an exaggerated level of leakage. Proposed Change: If present, filter slot cover(s) shall be replaced after removing filters. If filter slot cover is not present, seal the opening for the test and specify the installation of a cover. Response: Reject Any filter slot leakage under normal operating conditions should be included in the testing. Therefore we cannot seal this opening during testing.
If there is no filter cover exists, removing the filter without installing a temporary removes a plug, albeit a loose plug, in a very large hole. This will result in an exaggerated level of leakage.
If present, filter slot cover(s) shall be replaced after removing filters. If filter slot cover is not present, seal the opening for the test and specify the installation of a cover.
Comment #65Page Number: 11Paragraph / Figure / Table / Note: 3.1.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. The accuracy stated for Manometer seems high and is not clearly defined, For example, typically accuracies are rated as % of Full Scale or a % of reading. This statement does not define what the accuracies are compared to. Proposed Change: Manometer. A device that can measure pressure difference with an accuracy equal to or better than + or - 5% of full scale or .25 Pa, whichever is greater. Response: Accept in principle Changes have been made to the text as follows: 3.1.2. Manometer. A device that can measure pressure difference with an accuracy equal to or better than ± 1 % of reading, or 0.25 Pa (0.001 in. H2O), whichever is greater.
Changes have been made to the text as follows:
3.1.2. Manometer. A device that can measure pressure difference with an accuracy equal to or better than ± 1 % of reading, or 0.25 Pa (0.001 in. H2O), whichever is greater.
Comment #66Page Number: 16Paragraph / Figure / Table / Note: 3.1.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. It is evident from the language in this section and Chapter 8, that the following devises will not be permitted to be used: pitot tube, hot-wire and vane anemometers as in duct measurement devises large vane anemometers at the grilles and registers True Flow Plates in the filter slot. It is our opinion that these are all viable tools for measuring duct air flow that should be permitted and that an appropriate procedure be provided. Response: Reject This equipment does not have the required accuracy for this type of testing, and/or requires access to ducting and necessity of long straight ducts that makes them highly impractical for residential applications.
It is evident from the language in this section and Chapter 8, that the following devises will not be permitted to be used:
It is our opinion that these are all viable tools for measuring duct air flow that should be permitted and that an appropriate procedure be provided.
Comment #67Page Number: 19Paragraph / Figure / Table / Note: 5.1.3.2.3, 5.1.3.2.4Comment Intent: ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. It is unnecessary to measure the pressure between the flow capture element and the room and potentially terminate the test if the flow capture device automatically adjusts for this condition. Proposed Change: 5.1.3.2.3 Unless the flow capture device automatically adjusts for pressure difference between the capture hood element and the room, Tthe pressure difference between the flow hood capture element and the room shall be measured using the Manometer. If the pressure difference is more than 5 Pa, the procedure shall be terminated and no results recorded. 5.1.3.2.4 If the flow capture device automatically adjusts for pressure difference between the capture hood element and the room, or if the pressure difference is less than 5 PA then the average volumetric air flow through the air flow meter measured over at least a 10 second period, shall be recorded. Response: Reject The committee is unaware of any Passive Flow Hood equipment that performs the automatic adjustments as suggested by the commenter.
5.1.3.2.3 Unless the flow capture device automatically adjusts for pressure difference between the capture hood element and the room, Tthe pressure difference between the flow hood capture element and the room shall be measured using the Manometer. If the pressure difference is more than 5 Pa, the procedure shall be terminated and no results recorded.
5.1.3.2.4 If the flow capture device automatically adjusts for pressure difference between the capture hood element and the room, or if the pressure difference is less than 5 PA then the average volumetric air flow through the air flow meter measured over at least a 10 second period, shall be recorded.
The committee is unaware of any Passive Flow Hood equipment that performs the automatic adjustments as suggested by the commenter.
Comment #68Page Number: 4 and 10Paragraph / Figure / Table / Note: 3.3.6 and 3.5.3Comment Intent: ObjectionComment Type: TechnicalComment: Section 3.3.6 states, in part, that the “.. volume of the house shall be recorded.”. The term “Volume” needs to be defined because this value is currently subject to interpretation and yet is critical to the results produced by this test procedure. Note that changes will also be required in ANSI/RESNET 301-2014, including the following, which will have to be handled separately: Redefine “Conditioned Space” as “The volume, in ft3 or m3, An area or room within a building serviced by a space heating or cooling system designed to maintain space conditions in accordance with Section 4.2 of this Standard. Clarification as to whether interstitial spaces (e.g., floor cavities between conditioned stories, floor cavity between an unconditioned garage and a conditioned bonus room) shall be included in the Conditioned Space. Clarification as to whether unvented attics (both those that are maintained at a setpoint and those that are not), unvented crawlspaces (both those that are maintained at a setpoint and those that are not), and basements (those that are maintained at a setpoint and those that are not) shall be included in this definition. Currently, there is an apparent conflict in that the definition for Conditioned Space does not reference ANSI Standard Z765-2012, which relies upon finished floor area, yet the definition of Conditioned Floor Area references both the definition of Conditioned Space and ANSI Standard Z765-2012. In short, the definition both implies that Conditioned Floor Area should only include finished floor area and that it should include all conditioned floor area regardless of finish. Proposed Change: [3.3.6] 3.3.6. If the results of the test will be reported as Air Changes Per Hour at 50 Pa (0.2in. H2O)(ACH50), the Conditioned Space of the house, as defined by ANSI/RESNET 301-2014, volume of the house shall be recorded in units of ft3 or m3. [3.5.3] ACH50 = CFM50 x 60 / Building Volume Conditioned Space in cubic feet (8a) ACH50 = CFM50 x 60 / Building Volume Conditioned Space in cubic meters (8b) Response: Accept in principle The term “Infiltration Volume” has been defined and it has been clarified whether unvented attics, unvented crawlspaces, and basements shall be included in this definition.
Section 3.3.6 states, in part, that the “.. volume of the house shall be recorded.”. The term “Volume” needs to be defined because this value is currently subject to interpretation and yet is critical to the results produced by this test procedure.
Note that changes will also be required in ANSI/RESNET 301-2014, including the following, which will have to be handled separately:
Clarification as to whether unvented attics (both those that are maintained at a setpoint and those that are not), unvented crawlspaces (both those that are maintained at a setpoint and those that are not), and basements (those that are maintained at a setpoint and those that are not) shall be included in this definition. Currently, there is an apparent conflict in that the definition for Conditioned Space does not reference ANSI Standard Z765-2012, which relies upon finished floor area, yet the definition of Conditioned Floor Area references both the definition of Conditioned Space and ANSI Standard Z765-2012. In short, the definition both implies that Conditioned Floor Area should only include finished floor area and that it should include all conditioned floor area regardless of finish.
[3.3.6]
3.3.6. If the results of the test will be reported as Air Changes Per Hour at 50 Pa (0.2in. H2O)(ACH50), the Conditioned Space of the house, as defined by ANSI/RESNET 301-2014, volume of the house shall be recorded in units of ft3 or m3.
[3.5.3]
ACH50 = CFM50 x 60 / Building Volume Conditioned Space in cubic feet (8a)
ACH50 = CFM50 x 60 / Building Volume Conditioned Space in cubic meters (8b)
The term “Infiltration Volume” has been defined and it has been clarified whether unvented attics, unvented crawlspaces, and basements shall be included in this definition.
Comment #69Page Number: 4Paragraph / Figure / Table / Note: 3.3.7 and 3.5.3Comment Intent: ObjectionComment Type: TechnicalComment: Section 3.3.7 states, in part, that the “.. the floor area of the house shall be recorded.” The term “Floor Area” needs to be defined because this value is currently subject to interpretation and yet is critical to the results produced by this test procedure. Note that changes will also be required in ANSI/RESNET 301-2014, including the following, which will have to be handled separately: Clarification as to whether unvented attics (both those that are maintained at a setpoint and those that are not), unvented crawlspaces (both those that are maintained at a setpoint and those that are not), and basements (those that are maintained at a setpoint and those that are not) shall be included in the definition of Conditioned Floor Area. Currently, there is an apparent conflict in that the definition for Conditioned Floor Area references both the definition of Conditioned Space (i.e., the control volume) and ANSI Standard Z765-2012. In short, the definition both implies that Conditioned Floor Area should only include finished floor area and that it should include all conditioned floor area regardless of finish. Proposed Change: [3.3.7] 3.3.7. If the results of the test will be reported as Specific Leakage Area (SLA), the Conditioned Floor Area of the house, as defined by ANSI/RESNET 301-2014, floor area of the house shall be recorded in units of ft2 or m2. [3.5.3] SLA = 0.00694 x ELA in in2 / Building Floor Area Conditioned Floor Area in square feet (9a) SLA = 10.764 x ELA in m2 / Building Floor Area Conditioned Floor Area in square meters (8b) Response: Accept in principle The term “Conditioned Floor Area” has been defined and it has been clarified whether unvented attics, unvented crawlspaces, and basements shall be included in this definition.
Section 3.3.7 states, in part, that the “.. the floor area of the house shall be recorded.” The term “Floor Area” needs to be defined because this value is currently subject to interpretation and yet is critical to the results produced by this test procedure.
Clarification as to whether unvented attics (both those that are maintained at a setpoint and those that are not), unvented crawlspaces (both those that are maintained at a setpoint and those that are not), and basements (those that are maintained at a setpoint and those that are not) shall be included in the definition of Conditioned Floor Area. Currently, there is an apparent conflict in that the definition for Conditioned Floor Area references both the definition of Conditioned Space (i.e., the control volume) and ANSI Standard Z765-2012. In short, the definition both implies that Conditioned Floor Area should only include finished floor area and that it should include all conditioned floor area regardless of finish.
[3.3.7]
3.3.7. If the results of the test will be reported as Specific Leakage Area (SLA), the Conditioned Floor Area of the house, as defined by ANSI/RESNET 301-2014, floor area of the house shall be recorded in units of ft2 or m2.
SLA = 0.00694 x ELA in in2 / Building Floor Area Conditioned Floor Area in square feet (9a)
SLA = 10.764 x ELA in m2 / Building Floor Area Conditioned Floor Area in square meters (8b)
The term “Conditioned Floor Area” has been defined and it has been clarified whether unvented attics, unvented crawlspaces, and basements shall be included in this definition.
Comment #70Page Number: 3Paragraph / Figure / Table / Note: 3.2.10Comment Intent: ObjectionComment Type: TechnicalComment: A new sub-section should be added to Section 3.2.10 to address continuously operating local exhaust ventilation systems, and the subsequent sub-sections renumbered. Proposed Change: 3.2.10.2. Non-dampered ventilation openings of continuously operating local exhaust ventilation systems (e.g., bath fan, kitchen range fan) that connect conditioned space to the exterior or to unconditioned spaces shall be sealed, preferably at the exterior of the enclosure. Response: Accept
A new sub-section should be added to Section 3.2.10 to address continuously operating local exhaust ventilation systems, and the subsequent sub-sections renumbered.
3.2.10.2. Non-dampered ventilation openings of continuously operating local exhaust ventilation systems (e.g., bath fan, kitchen range fan) that connect conditioned space to the exterior or to unconditioned spaces shall be sealed, preferably at the exterior of the enclosure.
Comment #71Page Number: 4Paragraph / Figure / Table / Note: 3.2.8Comment Intent: ObjectionComment Type: TechnicalComment: Additional guidance needs to be provided regarding the operation of fans in adjacent attached dwelling units. Apparently, there is some ambiguity about whether Raters are permitted or not permitted to operate fans (e.g., bath exhaust fans, kitchen exhaust fans) in adjacent dwelling units in concert with the blower door while conducting the infiltration test. Add additional language to Section 3.2.8 that directly addresses the operation of fans in adjacent attached dwelling units during building enclosure leakage testing. Proposed Change: 3.2.8. Fans. Any fan or appliance capable of inducing airflow across the building enclosure shall be turned off including, but not limited to, clothes dryers, attic fans, kitchen and bathroom exhaust fans, air handlers, ventilation fans used in a whole-house mechanical ventilation system (e.g., a system intended to meet ASHRAE Standard 62.2), and crawlspace and attic ventilation fans. This requirement to turn fans off extends to accessible fans in adjacent attached dwelling units. Response: Accept
Additional guidance needs to be provided regarding the operation of fans in adjacent attached dwelling units. Apparently, there is some ambiguity about whether Raters are permitted or not permitted to operate fans (e.g., bath exhaust fans, kitchen exhaust fans) in adjacent dwelling units in concert with the blower door while conducting the infiltration test.
Add additional language to Section 3.2.8 that directly addresses the operation of fans in adjacent attached dwelling units during building enclosure leakage testing.
3.2.8. Fans. Any fan or appliance capable of inducing airflow across the building enclosure shall be turned off including, but not limited to, clothes dryers, attic fans, kitchen and bathroom exhaust fans, air handlers, ventilation fans used in a whole-house mechanical ventilation system (e.g., a system intended to meet ASHRAE Standard 62.2), and crawlspace and attic ventilation fans. This requirement to turn fans off extends to accessible fans in adjacent attached dwelling units.
Comment #72Page Number: 2Paragraph / Figure / Table / Note: 3.22Comment Intent: ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. The standard position for a garage door is closed, particularly in winter weather. Testing with the door open is inconsistent with Chapter 8 of the HERS Standard may artificially increase the tested air infiltration rate. Proposed Change: 3.2.2 Attached garages. If attached garage is not within the pressure boundary of the house, exterior garage doors shall be opened. If attached garage is within the pressure boundary of the home, eExterior garage doors shall be closed.. Response: Accept in principle Changes to section 3.2.2 have been made that are not exactly the same as the suggestion from the commenter, but achieve the same end. The new text is: 3.2.2. Attached garages. All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door.
3.2.2 Attached garages. If attached garage is not within the pressure boundary of the house, exterior garage doors shall be opened. If attached garage is within the pressure boundary of the home, eExterior garage doors shall be closed..
Changes to section 3.2.2 have been made that are not exactly the same as the suggestion from the commenter, but achieve the same end. The new text is:
3.2.2. Attached garages. All exterior garage doors and windows shall be closed and latched unless the blower door is installed between the house and the garage, in which case the garage shall be opened to outside by opening at least one exterior garage door.
Comment #73Page Number: 1-2Paragraph / Figure / Table / Note: Section 3Comment Intent: Not an ObjectionComment Type: TechnicalComment: NEHERS, which represents 16 accredited QA and Training providers represents over 350 raters in the Northeast, and the bulk of the Rating Industry from Maine to Delaware. Undefined terms/phrases in Section 3 include: "pressure boundary of the house", "conditioned space boundary", "conditioned attic" and "trickle vents". Uniform understanding and interpretation of these terms/phrases is critical to the proper use of the standard. Proposed Change: Minimize the number of terms and phrases that are used and define those terms which remain. Response: Accept in principle The terms "pressure boundary of the house", "conditioned space boundary", and "conditioned attic" have been removed from the standard. The committee believes that the remaining term mentioned by the respondent, “trickle vent”, does not warrant a definition at this time and, because the respondent did not propose a definition, none will be included at this time.
The terms "pressure boundary of the house", "conditioned space boundary", and "conditioned attic" have been removed from the standard. The committee believes that the remaining term mentioned by the respondent, “trickle vent”, does not warrant a definition at this time and, because the respondent did not propose a definition, none will be included at this time.
Comment #74Page Number: no page numberParagraph / Figure / Table / Note: 4.4.2 to 4.4.2.7Comment Intent: ObjectionComment Type: TechnicalComment: There is a new duct leakage to outside procedure found in section 4.4.2 of the draft proposal for the new ANSI Standard for air leakage testing. Essentially, the proposed standard, requires verification that the house pressure and duct pressures are accurate for the duct leakage to outside. Makes sense, and we should be doing that, however my concern is that the tolerance levels of 0.5 pa are too strict. Just the other day I was running a Tectite blower door test on a gusty day. Winds weren’t terribly gusty---10 to 20 mph (I looked it up just for this post J). I was not able to get a reading with a tolerance of 2 pa. That’s 4 x the level of tolerance of the 0.5 pa being proposed. I’m concerned, primarily because if the software could not get a reading at the 2 pa range, how we can expect a human to get a 0.5 pa range on those days. I was a bit impatient and ready to move on to taping ducts for the duct leakage test and decided to double the tolerance to 4 pa. Can you guess what the impact was in the range for % of accuracy reported in Tectite? 3%---not bad at all. I know this isn’t a direct correlation and more data would be needed, but I’m hoping RESNET ANSI Committee can provide some data to justify this strict of a range. I’m hoping it could correlates with a similar percentage accuracy and find a better sweet spot. Something closer to 3 pa seems reasonable, but I suspect even 1 pa could be much improved and save a lot of headache on getting it just right! Forgive my “long winded” rant (pun intended). I just want to make sure we have justification if we are going to take more time, money and most importantly cause some headache and painful joints from all the stair running to meet such a low tolerance. Proposed Change: 4.4.2.3. The Air-Moving Fan for the enclosure shall be unsealed, turned on, and adjusted to create an induced enclosure pressure difference of 25 Pa (±0.5 Pa) (0.1 ±0.002 in. H2O ±0.002) (± 3 pa) , defined as the induced enclosure pressure minus the Pre-Test Baseline Building Pressure. Note that this value is permitted to be positive or negative, which will be dependent upon whether the enclosure is pressurized or depressurized. Commentary ---batch change ±0.5 pa to ±3 pa whenver in reference to house pressure in the draft standard (or whatever is deemed acceptable, hopefully backed up by testing data to support the change) Response: Accept in principle The committee agrees with the respondent that the standard would be improved by defining a consistent practical tolerance for the pressure targets contained in the standard. Therefore, a tolerance of ±3 Pa has been added to infiltration target of 50 Pa in Section 3.4.1.2 and to the duct leakage target of 25 Pa in Section 4.4.2.3.
There is a new duct leakage to outside procedure found in section 4.4.2 of the draft proposal for the new ANSI Standard for air leakage testing. Essentially, the proposed standard, requires verification that the house pressure and duct pressures are accurate for the duct leakage to outside. Makes sense, and we should be doing that, however my concern is that the tolerance levels of 0.5 pa are too strict.
Just the other day I was running a Tectite blower door test on a gusty day. Winds weren’t terribly gusty---10 to 20 mph (I looked it up just for this post J). I was not able to get a reading with a tolerance of 2 pa. That’s 4 x the level of tolerance of the 0.5 pa being proposed. I’m concerned, primarily because if the software could not get a reading at the 2 pa range, how we can expect a human to get a 0.5 pa range on those days. I was a bit impatient and ready to move on to taping ducts for the duct leakage test and decided to double the tolerance to 4 pa. Can you guess what the impact was in the range for % of accuracy reported in Tectite? 3%---not bad at all. I know this isn’t a direct correlation and more data would be needed, but I’m hoping RESNET ANSI Committee can provide some data to justify this strict of a range. I’m hoping it could correlates with a similar percentage accuracy and find a better sweet spot. Something closer to 3 pa seems reasonable, but I suspect even 1 pa could be much improved and save a lot of headache on getting it just right!
Forgive my “long winded” rant (pun intended). I just want to make sure we have justification if we are going to take more time, money and most importantly cause some headache and painful joints from all the stair running to meet such a low tolerance.
The committee agrees with the respondent that the standard would be improved by defining a consistent practical tolerance for the pressure targets contained in the standard. Therefore, a tolerance of ±3 Pa has been added to infiltration target of 50 Pa in Section 3.4.1.2 and to the duct leakage target of 25 Pa in Section 4.4.2.3.
Comment #75Page Number: throughoutComment Intent: Not an ObjectionComment Type: TechnicalComment: NEHERS represents 16 Accredited QA and Training providers, over 350 raters and the bulk of the rating industry from Maine to Delaware. Pressure references are not used consistently throughout the document and do not properly consider the use of significant figures. Pressure is most often referenced in terms of 50 Pa (0.2 in. H2O), inferring that the two numbers are equivalent. Considering significant figures, 50 Pa is equal to any measurement >= to 49.5 and < 50.5. 0.2 in H20 is equal to anything >= 0.15 and <0.25, which is a much larger variation. The form 25 Pa (±0.5 Pa) (0.1 ±0.002 in. H2O) makes the tolerance much more clear and equal. Proposed Change: Either use appropriate number of significant figures or specify acceptable tolerences for pressure measurements. Response: Accept in principle The committee agrees with the respondent that the standard would be improved by defining a consistent practical tolerance for the pressure targets contained in the standard. Therefore, a tolerance of ±3 Pa has been added to infiltration target of 50 Pa in Section 3.4.1.2 and to the duct leakage target of 25 Pa in Section 4.4.2.3.
NEHERS represents 16 Accredited QA and Training providers, over 350 raters and the bulk of the rating industry from Maine to Delaware.
Pressure references are not used consistently throughout the document and do not properly consider the use of significant figures. Pressure is most often referenced in terms of 50 Pa (0.2 in. H2O), inferring that the two numbers are equivalent. Considering significant figures, 50 Pa is equal to any measurement >= to 49.5 and < 50.5. 0.2 in H20 is equal to anything >= 0.15 and <0.25, which is a much larger variation. The form 25 Pa (±0.5 Pa) (0.1 ±0.002 in. H2O) makes the tolerance much more clear and equal.
Either use appropriate number of significant figures or specify acceptable tolerences for pressure measurements.
Comment #76Page Number: 10Paragraph / Figure / Table / Note: 4Comment Intent: ObjectionComment Type: TechnicalComment: The first sentence of section 4 implies that sampling can not occur under these proposed testing standards for a multifamily building. Proposed Change: For multifamily buildings where each unit has its own duct system, each unit shall be tested individually. The leakage to outside test shallbe performed using a Blower Door in the main entry to the unit to pressurize the individual unit with reference to outside. If the main entry door is in an interior hallway thenthe hallway shall be well connected to outside through open windows or doors,or an exterior window or door (such as to deck or patio) shall be used. Only the ducts in the unit under test are tested Response: Accept
The first sentence of section 4 implies that sampling can not occur under these proposed testing standards for a multifamily building.
Comment #77Page Number: 1Paragraph / Figure / Table / Note: 2.1Comment Intent: ObjectionComment Type: TechnicalComment: This conflicts with ENERGY STAR v3 Proposed Change: The procedure for measuring the airflow of mechanical ventilation systems is also applicable to dwelling units in multifamily buildings three stories or less in height above ground, where each dwelling unit has its own ventilation system separate from other dwelling units Response: Accept in principle The committee agrees with the respondent that the test procedure should be applicable to all dwelling units in multifamily buildings, regardless of the number of stories in the building, because the scope requires that the ventilation system be separate from other dwelling units. Therefore, the phrase “three stories or less in height above ground” will be deleted. In addition, the same phrase will be deleted from the two proceeding paragraphs using a similar rationale (i.e., the heating and cooling air distribution system must be separate from other dwelling units, and the airtightness is evaluated for a single dwelling unit rather than for the overall building).
This conflicts with ENERGY STAR v3
The committee agrees with the respondent that the test procedure should be applicable to all dwelling units in multifamily buildings, regardless of the number of stories in the building, because the scope requires that the ventilation system be separate from other dwelling units. Therefore, the phrase “three stories or less in height above ground” will be deleted.
In addition, the same phrase will be deleted from the two proceeding paragraphs using a similar rationale (i.e., the heating and cooling air distribution system must be separate from other dwelling units, and the airtightness is evaluated for a single dwelling unit rather than for the overall building).