The following comments have been submitted:
Comment #1Page Number: 35Paragraph / Figure / Table / Note: Table 4.2.2(1) Note mComment Intent: Not an ObjectionComment Type: TechnicalComment: "Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation." Is the intent of this language to allow a bath fan to count as mechanical ventilation when it has a standard on/off switch with a label indicating that "on" provides fresh air, as long as the switch is in the "on" position at the time of final inspection? Proposed Change: If that isn't the intent, add language such as, "For an exhaust fan located in a bathroom, this On/Off switch cannot be the same switch that allows the occupant to turn the fan on/off on demand."
"Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation."
Is the intent of this language to allow a bath fan to count as mechanical ventilation when it has a standard on/off switch with a label indicating that "on" provides fresh air, as long as the switch is in the "on" position at the time of final inspection?
If that isn't the intent, add language such as, "For an exhaust fan located in a bathroom, this On/Off switch cannot be the same switch that allows the occupant to turn the fan on/off on demand."
Comment #2Page Number: 37Paragraph / Figure / Table / Note: Endnote t for Table 4.2.2(1)Comment Intent: ObjectionComment Type: TechnicalComment: The final sentence of Endnote (t) for Table 4.2.2(1) should be removed. The effect of this sentence can Increase the HERS Index by 6-7 points for a Rated Home that has two hot water heaters. This is because the Reference Home tank losses are restricted to a single water heater, while the Rated Home has losses for all the water heaters installed. In the absence of this sentence, the Reference Home is required to have the same number of water heaters as the Rated Home. In the example I examined, the home has a HERS Index in the upper 70's (under Std 301-2014 and Std 301-2019). It's in Climate Zone 2A, 2 stories, 4 bedrooms, 3400sqft CFA. The actual home had 2 water heaters. If the Reference Home is limited to a single storage water heater, the HERS Index is 6-7 points higher than before; when the Reference Home has 2 water heaters, the HERS Index remains as before. Many, many new homes are constructed with two water heaters. This will have a significant impact in the marketplace, and should be considered carefully and discussed widely. It may be desirable from an environmental policy standpoint, but the political ramifications are significant. Proposed Change: t. For a Rated Home with a nonstorage-type water heater or where a shared water heater provides service hot water to the Rated Home, a 40-gallon storage-type water heater of the same fuel as the proposed water heater shall be assumed for the Energy Rating Reference Home. For a Rated Home with a shared storage water heater, its tank losses shall be divided by the number of dwelling units served by the water heater. For tankless water heaters with an Energy Factor, EF shall be multiplied by 0.92 for Rated Home calculations. For tankless water heaters with a Uniform Energy Factor, UEF shall be multiplied by 0.94 for Rated Home calculations. For a Rated Home without a proposed water heater, a 40-gallon storage-type water heater of the same fuel as the predominant fuel type used for the heating system(s) shall be assumed for both the Rated and Energy Rating Reference Homes. In both cases, the Energy Factor of the water heater shall be as prescribed for the Energy Rating Reference Home water heater by Table 4.2.2(1). Where the Rated Home has multiple water heaters, the Energy Rating Reference Home shall have a 40-gallon storage-type water heater of the same fuel type as the predominant water heating type in the Rated Home.
The final sentence of Endnote (t) for Table 4.2.2(1) should be removed. The effect of this sentence can Increase the HERS Index by 6-7 points for a Rated Home that has two hot water heaters. This is because the Reference Home tank losses are restricted to a single water heater, while the Rated Home has losses for all the water heaters installed.
In the absence of this sentence, the Reference Home is required to have the same number of water heaters as the Rated Home.
In the example I examined, the home has a HERS Index in the upper 70's (under Std 301-2014 and Std 301-2019). It's in Climate Zone 2A, 2 stories, 4 bedrooms, 3400sqft CFA. The actual home had 2 water heaters. If the Reference Home is limited to a single storage water heater, the HERS Index is 6-7 points higher than before; when the Reference Home has 2 water heaters, the HERS Index remains as before.
Many, many new homes are constructed with two water heaters. This will have a significant impact in the marketplace, and should be considered carefully and discussed widely. It may be desirable from an environmental policy standpoint, but the political ramifications are significant.
t. For a Rated Home with a nonstorage-type water heater or where a shared water heater provides service hot water to the Rated Home, a 40-gallon storage-type water heater of the same fuel as the proposed water heater shall be assumed for the Energy Rating Reference Home. For a Rated Home with a shared storage water heater, its tank losses shall be divided by the number of dwelling units served by the water heater. For tankless water heaters with an Energy Factor, EF shall be multiplied by 0.92 for Rated Home calculations. For tankless water heaters with a Uniform Energy Factor, UEF shall be multiplied by 0.94 for Rated Home calculations. For a Rated Home without a proposed water heater, a 40-gallon storage-type water heater of the same fuel as the predominant fuel type used for the heating system(s) shall be assumed for both the Rated and Energy Rating Reference Homes. In both cases, the Energy Factor of the water heater shall be as prescribed for the Energy Rating Reference Home water heater by Table 4.2.2(1). Where the Rated Home has multiple water heaters, the Energy Rating Reference Home shall have a 40-gallon storage-type water heater of the same fuel type as the predominant water heating type in the Rated Home.
Comment #3Page Number: 23-24Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: ObjectionComment Type: TechnicalComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Stueben, Executive Director (jeff@coolroofs.org). It is not appropriate to reference ANSI/CRRC S100 for the determination of the Solar Absorptance of exterior wall products (above-grade walls) because ANSI/CRRC S100 is currently limited to the specimen preparation and test methods for determining the initial and aged radiative properties of roofing products. Walls are not included in the existing ANSI/CRRC S100 because the solar spectral irradiance of vertical surfaces (walls) differs from that of horizontal or sloped surfaces (roofs). To measure the Solar Reflectance of walls requires changing a setting on the measurement device, and this is not explained in ANSI/CRRC S100 since the standard only applies to sloped and horizontal surfaces. Although the CRRC is currently in the process of developing a rating program for exterior wall products, the program and any related consensus standards will not be available until after the revised RESNET/ICC 301 standard is published. Therefore, we recommend replacing the reference to ANSI/CRRC S100 with references to other consensus standards that can be used for measuring the Solar Reflectance of exterior wall products, such as ASTM C1549 and ASTM E903. We also recommend adding an informative note for the use of a standard test method for measuring Solar Reflectance that is located in Appendix 9 of the Cool Roof Rating Council’s CRRC-1 Product Rating Program Manual. The standard was vetted by the CRRC Technical Committee, which is a balanced group of 32 members representing accredited testing laboratories, national laboratories, device manufacturers, roofing product manufacturers, and general interest stakeholders. If RESNET chooses to cite these standards, please add language that requires the use of the ASTM G197 air-mass 1.5 sun-facing global vertical — rather than a global horizontal or global tilt — solar spectral irradiance for measuring vertical surfaces. Additionally, since the RESNET/ICC 301 standard uses Solar Absorptance as a metric instead of Solar Reflectance, users should be instructed to subtract the measured Solar Reflectance value from the number one in order to obtain the Solar Absorptance value (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users. Proposed Change: TABLE 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes Building Component: Above Grade Walls Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100 ASTM C1549 or ASTM E903 using the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance for the measurement of Solar Reflectance.1 The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance). 1(Informative Note) Solar Reflectance can also be measured in accordance with the “Standard Test Method for Determining the Directional-Hemispherical Solar Reflectance of Materials Using a Directional-Hemispherical Portable Reflectometer” with the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance. The standard is located in Appendix 9 of the CRRC-1 Product Rating Program Manual.
I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Stueben, Executive Director (jeff@coolroofs.org).
It is not appropriate to reference ANSI/CRRC S100 for the determination of the Solar Absorptance of exterior wall products (above-grade walls) because ANSI/CRRC S100 is currently limited to the specimen preparation and test methods for determining the initial and aged radiative properties of roofing products. Walls are not included in the existing ANSI/CRRC S100 because the solar spectral irradiance of vertical surfaces (walls) differs from that of horizontal or sloped surfaces (roofs). To measure the Solar Reflectance of walls requires changing a setting on the measurement device, and this is not explained in ANSI/CRRC S100 since the standard only applies to sloped and horizontal surfaces.
Although the CRRC is currently in the process of developing a rating program for exterior wall products, the program and any related consensus standards will not be available until after the revised RESNET/ICC 301 standard is published. Therefore, we recommend replacing the reference to ANSI/CRRC S100 with references to other consensus standards that can be used for measuring the Solar Reflectance of exterior wall products, such as ASTM C1549 and ASTM E903. We also recommend adding an informative note for the use of a standard test method for measuring Solar Reflectance that is located in Appendix 9 of the Cool Roof Rating Council’s CRRC-1 Product Rating Program Manual. The standard was vetted by the CRRC Technical Committee, which is a balanced group of 32 members representing accredited testing laboratories, national laboratories, device manufacturers, roofing product manufacturers, and general interest stakeholders. If RESNET chooses to cite these standards, please add language that requires the use of the ASTM G197 air-mass 1.5 sun-facing global vertical — rather than a global horizontal or global tilt — solar spectral irradiance for measuring vertical surfaces.
Additionally, since the RESNET/ICC 301 standard uses Solar Absorptance as a metric instead of Solar Reflectance, users should be instructed to subtract the measured Solar Reflectance value from the number one in order to obtain the Solar Absorptance value (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users.
TABLE 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes
Building Component: Above Grade Walls
Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100 ASTM C1549 or ASTM E903 using the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance for the measurement of Solar Reflectance.1 The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
1(Informative Note) Solar Reflectance can also be measured in accordance with the “Standard Test Method for Determining the Directional-Hemispherical Solar Reflectance of Materials Using a Directional-Hemispherical Portable Reflectometer” with the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance. The standard is located in Appendix 9 of the CRRC-1 Product Rating Program Manual.
Comment #4Page Number: 24-25Paragraph / Figure / Table / Note: Table 4..2.2(1) as it pertains to "roofs"Comment Intent: ObjectionComment Type: TechnicalComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Stueben, Executive Director (jeff@coolroofs.org). ANSI/CRRC S100 includes test methods for determining the Solar Reflectance and not the Solar Absorptance of roofing products. Since the RESNET/ICC 301 standard uses Solar Absorptance as a metric, users should be instructed to subtract the measured Solar Reflectance from the number one to obtain the Solar Absorptance (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance. Proposed Change: TABLE 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes Building Component: Roof Values from Table 4.2.2(5) shall be used to determine Solar Absorptance, except where test data are provided for roof surface in accordance with ANSI/CRRC S100 for the measurement of Solar Reflectance. The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
ANSI/CRRC S100 includes test methods for determining the Solar Reflectance and not the Solar Absorptance of roofing products. Since the RESNET/ICC 301 standard uses Solar Absorptance as a metric, users should be instructed to subtract the measured Solar Reflectance from the number one to obtain the Solar Absorptance (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance.
Building Component: Roof
Values from Table 4.2.2(5) shall be used to determine Solar Absorptance, except where test data are provided for roof surface in accordance with ANSI/CRRC S100 for the measurement of Solar Reflectance. The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
Comment #5Page Number: 42Paragraph / Figure / Table / Note: Table 4.2.2(5) default solar absorptanceComment Intent: ObjectionComment Type: TechnicalComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Stueben, Executive Director (jeff@coolroofs.org). Since the RESNET/ICC 301 standard uses Solar Absorptance as a metric, users should be instructed to subtract the measured Solar Reflectance from the number one to obtain the Solar Absorptance (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance. Proposed Change: Table 4.2.2(5) Default Solar Absorptance for Various Roofing Surfaces Roof Materials Absorptance1 White Composition Shingles 0.80 White Tile (including concrete) 0.60 White Metal or White TPO 0.50 All others 0.92 1 Solar absorptance values can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
Since the RESNET/ICC 301 standard uses Solar Absorptance as a metric, users should be instructed to subtract the measured Solar Reflectance from the number one to obtain the Solar Absorptance (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance.
Table 4.2.2(5) Default Solar Absorptance for Various Roofing Surfaces
Roof Materials
Absorptance1
White Composition Shingles
0.80
White Tile (including concrete)
0.60
White Metal or White TPO
0.50
All others
0.92
1 Solar absorptance values can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
Comment #6Page Number: 113-114Paragraph / Figure / Table / Note: Section 6, Normative ReferencesComment Intent: ObjectionComment Type: TechnicalComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org). The Normative References list in section 6 of the RESNET/ICC 301 standard should cite the newest version of ANSI/CRRC S100 (i.e. 2021 edition), which will be available spring 2021. Additionally, the location of the Cool Roof Rating Council is now Portland, Oregon. In addition, the Normative References list should include citations for ASTM C1549, ASTM E903, and ASTM G197 based on the separate comments we submitted for the replacement of the proposed reference to ANSI/CRRC S100 with these ASTM standards, as it pertains to above-grade walls. For clarification, we are not proposing to replace the reference to ANSI/CRRC S100 for roofs. Proposed Change: 6. Normative References ANSI/CRRC S100-201621, “Standard Test Methods for Determining Radiative Properties of Materials,” Cool Roof Rating Council, Oakland, CA Portland, OR. www.coolroofs.org ASTM C1549-16 “Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer.” ASTM International, West Conshohocken, PA. https://doi.org/10.1520/C1549-16 ASTM E903-20 “Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres.” ASTM International, West Conshohocken, PA. https://doi.org/10.1520/E0903-20 ASTM G197-14 “Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20° Tilted and Vertical Surfaces. ASTM International, West Conshohocken, PA. https://doi.org/10.1520/G0197-14
I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org).
The Normative References list in section 6 of the RESNET/ICC 301 standard should cite the newest version of ANSI/CRRC S100 (i.e. 2021 edition), which will be available spring 2021. Additionally, the location of the Cool Roof Rating Council is now Portland, Oregon.
In addition, the Normative References list should include citations for ASTM C1549, ASTM E903, and ASTM G197 based on the separate comments we submitted for the replacement of the proposed reference to ANSI/CRRC S100 with these ASTM standards, as it pertains to above-grade walls. For clarification, we are not proposing to replace the reference to ANSI/CRRC S100 for roofs.
6. Normative References
ANSI/CRRC S100-201621, “Standard Test Methods for Determining Radiative Properties of Materials,” Cool Roof Rating Council, Oakland, CA Portland, OR. www.coolroofs.org
ASTM C1549-16 “Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer.” ASTM International, West Conshohocken, PA. https://doi.org/10.1520/C1549-16
ASTM E903-20 “Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres.” ASTM International, West Conshohocken, PA. https://doi.org/10.1520/E0903-20
ASTM G197-14 “Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20° Tilted and Vertical Surfaces. ASTM International, West Conshohocken, PA. https://doi.org/10.1520/G0197-14
Comment #7Page Number: 115Paragraph / Figure / Table / Note: Section 7, Informative ReferencesComment Intent: ObjectionComment Type: GeneralComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org). The Informative References list in section 7 of the RESNET/ICC 301 standard should include a reference to Appendix 9 of the CRRC-1 Product Rating Program Manual, which contains the “Standard Test Method for Determining the Directional-Hemispherical Solar Reflectance of Materials Using a Directional-Hemispherical Portable Reflectometer” for the measurement of the Solar Reflectance of above-grade walls, based on the separate comments we submitted regarding the inclusion of an informative note in TABLE 4.2.2(1) that references the standard in Appendix 9 of the CRRC-1 Product Rating Program Manual. The standard was vetted by the CRRC Technical Committee, which is a balanced group of 32 members representing accredited testing laboratories, national laboratories, device manufacturers, roofing product manufacturers, and general interest stakeholders. Proposed Change: 6. Informative References Cool Roof Rating Council, CRRC-1 Product Rating Program Manual, Appendix 9, 2001. Portland, OR, www.coolroofs.org
The Informative References list in section 7 of the RESNET/ICC 301 standard should include a reference to Appendix 9 of the CRRC-1 Product Rating Program Manual, which contains the “Standard Test Method for Determining the Directional-Hemispherical Solar Reflectance of Materials Using a Directional-Hemispherical Portable Reflectometer” for the measurement of the Solar Reflectance of above-grade walls, based on the separate comments we submitted regarding the inclusion of an informative note in TABLE 4.2.2(1) that references the standard in Appendix 9 of the CRRC-1 Product Rating Program Manual. The standard was vetted by the CRRC Technical Committee, which is a balanced group of 32 members representing accredited testing laboratories, national laboratories, device manufacturers, roofing product manufacturers, and general interest stakeholders.
6. Informative References
Cool Roof Rating Council, CRRC-1 Product Rating Program Manual, Appendix 9, 2001. Portland, OR, www.coolroofs.org
Comment #8Page Number: B-18Paragraph / Figure / Table / Note: Normative Appendix B, Inspection Procedures for Minimum Rated Features as it pertains to Wall Assembly: ColorComment Intent: ObjectionComment Type: TechnicalComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org). It is not appropriate to reference ANSI/CRRC S100 for the determination of the Solar Absorptance of exterior wall products (above-grade walls) because ANSI/CRRC S100 is currently limited to the specimen preparation and test methods for determining the initial and aged radiative properties of roofing products. Walls are not included in the existing ANSI/CRRC S100 because the solar spectral irradiance of vertical surfaces (walls) differs from that of horizontal or sloped surfaces (roofs). To measure the Solar Reflectance of walls requires changing a setting on the measurement device, and this is not explained in ANSI/CRRC S100 since the standard only applies to sloped and horizontal surfaces. Although the CRRC is currently in the process of developing a rating program for exterior wall products, the program and any related consensus standards will not be available until after the revised RESNET/ICC 301 standard is published. Therefore, we recommend replacing the reference to ANSI/CRRC S100 with references to other consensus standards that can be used for measuring the Solar Reflectance of exterior wall products, such as ASTM C1549 and ASTM E903. We also recommend adding an informative note for the use of a standard test method for measuring Solar Reflectance that is located in Appendix 9 of the Cool Roof Rating Council’s CRRC-1 Product Rating Program Manual. The standard was vetted by the CRRC Technical Committee, which is a balanced group of 32 members representing accredited testing laboratories, national laboratories, device manufacturers, roofing product manufacturers, and general interest stakeholders. If RESNET chooses to cite these standards, please add language that requires the use of the ASTM G197 air-mass 1.5 sun-facing global vertical — rather than a global horizontal or global tilt — solar spectral irradiance for measuring vertical surfaces. Additionally, since the RESNET/ICC 301 standard uses Solar Absorptance as a metric instead of Solar Reflectance, users should be instructed to subtract the measured Solar Reflectance value from the number one in order to obtain the Solar Absorptance value (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users. Proposed Change: Building Element: Wall Assembly Rated Feature: Color Category: On-Site Inspection Protocol Identify the color of the walls according to Table 4.2.2 (4), except where test data are provided for wall surfaces in accordance with ANSI/CRRC S100 ASTM C1549 or ASTM E903 using the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance for the measurement of Solar Reflectance.1 The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance). 1(Informative Note) Solar Reflectance can also be measured in accordance with the “Standard Test Method for Determining the Directional-Hemispherical Solar Reflectance of Materials Using a Directional-Hemispherical Portable Reflectometer” with the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance. The standard is located in Appendix 9 of the CRRC-1 Product Rating Program Manual.
Building Element: Wall Assembly
Rated Feature: Color
Category: On-Site Inspection Protocol
Identify the color of the walls according to Table 4.2.2 (4), except where test data are provided for wall surfaces in accordance with ANSI/CRRC S100 ASTM C1549 or ASTM E903 using the ASTM G197 air-mass 1.5 sun-facing global vertical solar spectral irradiance for the measurement of Solar Reflectance.1 The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
Comment #9Page Number: B-25Paragraph / Figure / Table / Note: Normative Appendix B - Inspection Procedures for Minimum Rated Features as it pertains to Roof/Ceiling Assembly: ColorComment Intent: ObjectionComment Type: EditorialComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org). The proposed language for Roof Color mentions “wall” surfaces but should instead state “roof” surfaces since this provision applies to the color of the roof and not the color of above-grade walls. Additionally, since the RESNET/ICC 301 standard uses Solar Absorptance as a metric instead of Solar Reflectance, users should be instructed to subtract the measured Solar Reflectance value from the number one in order to obtain the Solar Absorptance value (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance. Proposed Change: Building Element: Roof/Ceiling Assembly Rated Feature: Roof Color Category: On-Site Inspection Protocol Identify the color and material of the Roof according to Table 4.2.2(5), except where test data are provided for wall roof surfaces in accordance with ANSI/CRRC S100 for the measurement of solar reflectance. The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
The proposed language for Roof Color mentions “wall” surfaces but should instead state “roof” surfaces since this provision applies to the color of the roof and not the color of above-grade walls.
Additionally, since the RESNET/ICC 301 standard uses Solar Absorptance as a metric instead of Solar Reflectance, users should be instructed to subtract the measured Solar Reflectance value from the number one in order to obtain the Solar Absorptance value (i.e. Solar Absorptance = 1 – Solar Reflectance). We believe this will mitigate any confusion by users, especially since the radiative performance ratings of roofing products that are available to consumers typically list Solar Reflectance and not Solar Absorptance.
Building Element: Roof/Ceiling Assembly
Rated Feature: Roof Color
Identify the color and material of the Roof according to Table 4.2.2(5), except where test data are provided for wall roof surfaces in accordance with ANSI/CRRC S100 for the measurement of solar reflectance. The Solar Absorptance value can be obtained by subtracting the measured Solar Reflectance value from the number one (Solar Absorptance = 1 – Solar Reflectance).
Comment #10Page Number: 42-44Paragraph / Figure / Table / Note: 4.2.2.1Comment Intent: ObjectionComment Type: EditorialComment: I am the chair of the CRRC Ratings, Codes and Standards Committee, and I have been authorized to present this comment on behalf of the Cool Roof Rating Council by Mr. Jeffrey Steuben, Executive Director (jeff@coolroofs.org). Section 4.2.2 references a number of tables, including new tables, but the table numbering is incorrect. For example, Section 4.2.2.1 covers wall framing but references Table 4.2.2(5) which now applies to roof solar absorptance and not the default framing fractions for enclosure elements. The table number and all corresponding references should be changed to “4.2.2(6),” and subsequent table numbers should be updated accordingly. We are not proposing any other changes to the tables. Proposed Change: Table 4.2.2(56) – Default Framing Fractions for Enclosure Elements 4.2.2.1 For ratings where the framing is not visible at the time of the site inspection, the framing fractions shall equal the highest default framing fraction for the assembly component listed in Table 4.2.2(56). For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for their framing spacing listed in Table 4.2.2(56). Wall assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2((56), unless the conditions in Section 4.2.2.1.1 or Section 4.2.2.1.2 have been met. 41 (Informative Note) For example, a SIP wall or other engineered framed wall is permitted to use a framing fraction better than the defaults in table 4.2.2(56) if it meets the requirements of this section.
Section 4.2.2 references a number of tables, including new tables, but the table numbering is incorrect. For example, Section 4.2.2.1 covers wall framing but references Table 4.2.2(5) which now applies to roof solar absorptance and not the default framing fractions for enclosure elements. The table number and all corresponding references should be changed to “4.2.2(6),” and subsequent table numbers should be updated accordingly. We are not proposing any other changes to the tables.
Table 4.2.2(56) – Default Framing Fractions for Enclosure Elements
4.2.2.1
For ratings where the framing is not visible at the time of the site inspection, the framing fractions shall equal the highest default framing fraction for the assembly component listed in Table 4.2.2(56).
For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for their framing spacing listed in Table 4.2.2(56). Wall assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2((56), unless the conditions in Section 4.2.2.1.1 or Section 4.2.2.1.2 have been met.
41 (Informative Note) For example, a SIP wall or other engineered framed wall is permitted to use a framing fraction better than the defaults in table 4.2.2(56) if it meets the requirements of this section.
Comment #11Page Number: 38Comment Intent: ObjectionComment Type: TechnicalComment: x. When both of the following conditions are met and documented, duct leakage testing is not required. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes. This new statement on page 38 is confusing. Does the 4% LTO only apply when the duct system has < a 10ft total length? If we meet the above standards in order to skip the duct test we have to apply the .88 DSE but we can use 4CM/100cfa for LTO if no part of the system is in an ext. wall or floor over unconditioned space? There is currently no way to model this in Ekotrope. You cannot simultaneously apply the DSE and enter a value for LTO. It is unclear in REMRate how you would enter this. Proposed Change: To clarify if the 4% LTO applies only when the supply is < 10ft, the paragraph should read: To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. and a value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
x. When both of the following conditions are met and documented, duct leakage testing is not required.
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
This new statement on page 38 is confusing. Does the 4% LTO only apply when the duct system has < a 10ft total length?
If we meet the above standards in order to skip the duct test we have to apply the .88 DSE but we can use 4CM/100cfa for LTO if no part of the system is in an ext. wall or floor over unconditioned space? There is currently no way to model this in Ekotrope. You cannot simultaneously apply the DSE and enter a value for LTO. It is unclear in REMRate how you would enter this.
To clarify if the 4% LTO applies only when the supply is < 10ft, the paragraph should read:
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. and a value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
Comment #12Page Number: 38Comment Intent: ObjectionComment Type: TechnicalComment: x. When both of the following conditions are met and documented, duct leakage testing is not required. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes. This new statement on page 38 is confusing. Does the 4% LTO only apply when the duct system has < a 10ft total length? If we meet the above standards in order to skip the duct test we have to apply the .88 DSE but we can use 4CM/100cfa for LTO if no part of the system is in an ext. wall or floor over unconditioned space? There is currently no way to model this in Ekotrope. You cannot simultaneously apply the DSE and enter a value for LTO. It is unclear in REMRate how you would enter this. Proposed Change: To clarify if the 4% LTO applies only when the supply is < 10ft, the paragraph should read: To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. and a value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
Comment #13Page Number: A-1and A-2Comment Intent: Not an ObjectionComment Type: GeneralComment: A-1.2 Minimum Specific Application Requirements: Insulation installed in framed floor assemblies shall be in substantial and permanent contact with the subfloor. Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, perimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume. This seems to be saying that at a location such as where the floor over the garage meets the garage common wall, the rim insulation does not need to fill the entire cavity, but it is unclear. Proposed Change: An illustration depicting this would be helpful.
Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, perimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume.
This seems to be saying that at a location such as where the floor over the garage meets the garage common wall, the rim insulation does not need to fill the entire cavity, but it is unclear.
An illustration depicting this would be helpful.
Comment #14Page Number: B-29Paragraph / Figure / Table / Note: Building Element Table - WindowsComment Intent: ObjectionComment Type: GeneralComment: This section indicates we are to determine and record window construction. Current modeling software does not allow for recording for any of these variations. The modeling software asks for U-value and Solar Heat Gain Coefficient. Proposed Change: Revisit this addition when available software is compatible with the requirement.
This section indicates we are to determine and record window construction. Current modeling software does not allow for recording for any of these variations. The modeling software asks for U-value and Solar Heat Gain Coefficient.
Revisit this addition when available software is compatible with the requirement.
Comment #15Page Number: 117Paragraph / Figure / Table / Note: Normative Appendix A A-1. InsulationComment Intent: ObjectionComment Type: TechnicalComment: The equivelence of a Grade I instalation and an IECC compliant installation needs to be clearly expressed in the 1st section of Normative Appendix A so that Raters who do both HERS Ratings and Code Complaince Ratings on a single home understand that the IECC is expecting a different level of installation and inspection than is required by a simple asset rating. This is an issue because Section R405 total building performance, Section R402 UA trade off compliance, and Section R406 Energy Rating Index all us software where currenly grade 3 insulation can be modeled and passing compliance certificates delivered. This is contrary to the express intent of the IECC that states that insulaiton must be installed per manufacture instructions and the requirements of Table R402.4.1.1. Proposed Change: In order to meet the requirements of a Grade I or Grade II insulation rating, the insulation material shall be installed in accordance with the minimum installation requirements of this Appendix and the requirements specified by ASTM standards C727, C1015, C1743, C1320, C1321 and C1848 as described below in the insulation grading section. Installations not complying with the minimum installation requirements of this Appendix, the relevant ASTM standard for the type insulation, or the Grade I or Grade II coverage requirements shall be considered Grade III installations. Grade III installations shall be recorded and shall be modeled as specified by Section 4.2.2.2.2 of this Standard. When inspection the installation of insulaiton for compliance with the iECC, Installations not complying with the minimum installation requirements of the IECC, this Appendix, the relevant ASTM standard for the type insulation, or the Grade I coverage requirements shall be considered not in compliance with an IECC installation.
The equivelence of a Grade I instalation and an IECC compliant installation needs to be clearly expressed in the 1st section of Normative Appendix A so that Raters who do both HERS Ratings and Code Complaince Ratings on a single home understand that the IECC is expecting a different level of installation and inspection than is required by a simple asset rating. This is an issue because Section R405 total building performance, Section R402 UA trade off compliance, and Section R406 Energy Rating Index all us software where currenly grade 3 insulation can be modeled and passing compliance certificates delivered. This is contrary to the express intent of the IECC that states that insulaiton must be installed per manufacture instructions and the requirements of Table R402.4.1.1.
In order to meet the requirements of a Grade I or Grade II insulation rating, the insulation material shall be installed in accordance with the minimum installation requirements of this Appendix and the requirements specified by ASTM standards C727, C1015, C1743, C1320, C1321 and C1848 as described below in the insulation grading section.
Installations not complying with the minimum installation requirements of this Appendix, the relevant ASTM standard for the type insulation, or the Grade I or Grade II coverage requirements shall be considered Grade III installations. Grade III installations shall be recorded and shall be modeled as specified by Section 4.2.2.2.2 of this Standard.
When inspection the installation of insulaiton for compliance with the iECC, Installations not complying with the minimum installation requirements of the IECC, this Appendix, the relevant ASTM standard for the type insulation, or the Grade I coverage requirements shall be considered not in compliance with an IECC installation.
Comment #16Page Number: 35Paragraph / Figure / Table / Note: Table 4.2.2(1), note "m"Comment Intent: ObjectionComment Type: TechnicalComment: In note (m) to Table 4.2.2(1), I disagree to the 2nd sentence that is being added. "Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation" I disagree that 'labeling' of an On/Off switch should play a role in whether a ventilation fan meets the definition of a 'dwelling unit mechanical ventilation system', as defined in Section 3. That definition clearly states that a "Dwelling Unit Mechanical Ventilation System" is a "Ventilation system, operating continuously or through a programmed intermittent schedule, consisting of powered Ventilation equipment related mechanical components, and automated control devices that provides Dwelling Unit Ventilation at a known or measured airflow rate." The key word is "automated". I would instead support a Normative Note added to the definition of DUMVS, that states clearly that labeling is not sufficient since the requirement is ‘automated’ control, not labeled manual control. Proposed Change: Dwelling Unit Mechanical Ventilation System – A Ventilation system, operating continuously or through a programmed intermittent schedule, consisting of powered Ventilation equipment, related mechanical components, and automated# control devices that provides Dwelling Unit Ventilation at a known or measured airflow rate. ## (Normative Note) A switch or thermostat setting, which enables the occupant to turn a system on and off, is not considered automated, continuous, nor programmed. The presence of a ventilation override control is permitted, if the override control is labeled with text or an icon that clearly indicate its function is to turn off the ventilation system. m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan, fan watts shall be the value observed either per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode.
In note (m) to Table 4.2.2(1), I disagree to the 2nd sentence that is being added.
"Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation"
I disagree that 'labeling' of an On/Off switch should play a role in whether a ventilation fan meets the definition of a 'dwelling unit mechanical ventilation system', as defined in Section 3. That definition clearly states that a "Dwelling Unit Mechanical Ventilation System" is a "Ventilation system, operating continuously or through a programmed intermittent schedule, consisting of powered Ventilation equipment related mechanical components, and automated control devices that provides Dwelling Unit Ventilation at a known or measured airflow rate."
Dwelling Unit Mechanical Ventilation System – A Ventilation system, operating continuously or through a programmed intermittent schedule, consisting of powered Ventilation equipment, related mechanical components, and automated# control devices that provides Dwelling Unit Ventilation at a known or measured airflow rate.
## (Normative Note) A switch or thermostat setting, which enables the occupant to turn a system on and off, is not considered automated, continuous, nor programmed. The presence of a ventilation override control is permitted, if the override control is labeled with text or an icon that clearly indicate its function is to turn off the ventilation system.
m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan, fan watts shall be the value observed either per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode.
Comment #17Page Number: 24Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: ObjectionComment Type: TechnicalComment: While I approve of the added row to Table 4.2.2 (1) to clarify the distinct types of above-grade walls and the conditions that are adjacent to them, I disagree that interior walls of the ERRH in MF buildings should be held to the same insulation performance as Exterior walls. That doesn’t seem like it would have been required of a Reference Home from 2006. Current building/energy code does not always require insulation for those interior walls, unless they are the building thermal boundary, which may be the case for USV, but not the case for MF Buffer Boundary or Unrated Heated Space. Table 4.2.2(1) should instead indicate that those walls next to semi-conditioned spaces are uninsulated or some nominal value, like R-11, which may have been common practice for those walls in 2006 at least for sound considerations. It is understood that the heat loss across these interior walls would be substantially less than those walls exposed to ambient conditions, so the impact of this R-value may not cause significant changes to the ERI either way. However, it does reflect an energy penalty for MF dwelling units in certain climate zones as written now, that are meeting current code by not insulating those interior walls at all. Proposed Change: Table 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes Building Component Energy Rating Reference Home Rated Home Above-grade walls separating Conditioned Space Volume from outdoor environment or Unconditioned Space Volume Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100.Same as Rated Home Same as Rated Home Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space Type: wood frame Gross Area: same as Rated Home U-Factor: 0.33 from Table 4.2.2(2) Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100. Same as Rated Home
While I approve of the added row to Table 4.2.2 (1) to clarify the distinct types of above-grade walls and the conditions that are adjacent to them, I disagree that interior walls of the ERRH in MF buildings should be held to the same insulation performance as Exterior walls. That doesn’t seem like it would have been required of a Reference Home from 2006. Current building/energy code does not always require insulation for those interior walls, unless they are the building thermal boundary, which may be the case for USV, but not the case for MF Buffer Boundary or Unrated Heated Space. Table 4.2.2(1) should instead indicate that those walls next to semi-conditioned spaces are uninsulated or some nominal value, like R-11, which may have been common practice for those walls in 2006 at least for sound considerations. It is understood that the heat loss across these interior walls would be substantially less than those walls exposed to ambient conditions, so the impact of this R-value may not cause significant changes to the ERI either way. However, it does reflect an energy penalty for MF dwelling units in certain climate zones as written now, that are meeting current code by not insulating those interior walls at all.
Table 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes
Building Component
Energy Rating Reference Home
Rated Home
Above-grade walls separating Conditioned Space Volume from outdoor environment or Unconditioned Space Volume
Type: wood frame
Gross Area: same as Rated Home
U-Factor: from Table 4.2.2(2)
Solar Absorptance = 0.75
Emittance = 0.90
Same as Rated Home
Same as Rated Home Same as Rated Home
Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100.Same as Rated Home
Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space
U-Factor: 0.33 from Table 4.2.2(2)
Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100.
Comment #18Page Number: 38Paragraph / Figure / Table / Note: Table 4.2.2(1), note "x"Comment Intent: ObjectionComment Type: TechnicalComment: To make the new proposed alternatives easier to understand, I propose moving the DSE of 1.0 option out of this note "x" and directly into the Table 4.2.2(1). Additionally, improve language in note "x" and carry through to Appendix B. Proposed Change: Thermal distribution systems Thermal Distribution System Efficiency (DSE) of 0.80 shall be applied to both the heating and cooling system efficiencies. Forced air distribution systems duct leakage to outside testsw,x, y, z shall be conducted and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380 with the air handler installed, and the energy impacts calculated with the ducts located and insulated as in the Rated Home. Forced air distribution systems duct area shall be the same as the Rated Homeaa. For ductless distribution systems or distribution systems where the total supply duct length, including all supply trunks and branches is ≤ 10 ft: DSE=1.00 For hydronic distribution systems: DSE=1.00 x. When both of the following conditions are met and documented, duct leakage testing is not required. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. Alternatively, aA value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if the above conditions are met and no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes. Appendix B Leakage of air ducts DetermineDetermine and record air leakage from ducts Use default estimates as applicable in Table 4.2.2(1) or fFollow Procedure for Measuring Airtightness of Duct Systems in ANSI/RESNET/ICC 380. The air handler shall be installed prior to testing.
To make the new proposed alternatives easier to understand, I propose moving the DSE of 1.0 option out of this note "x" and directly into the Table 4.2.2(1). Additionally, improve language in note "x" and carry through to Appendix B.
Thermal distribution systems
Thermal Distribution System Efficiency (DSE) of 0.80 shall be applied to both the heating and cooling system efficiencies.
Forced air distribution systems duct leakage to outside testsw,x, y, z shall be conducted and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380 with the air handler installed, and the energy impacts calculated with the ducts located and insulated as in the Rated Home.
Forced air distribution systems duct area shall be the same as the Rated Homeaa.
For ductless distribution systems or distribution systems where the total supply duct length, including all supply trunks and branches is ≤ 10 ft: DSE=1.00
For hydronic distribution systems: DSE=1.00
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. Alternatively, aA value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if the above conditions are met and no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
Appendix B
Leakage of air ducts
DetermineDetermine and record air leakage from ducts
Use default estimates as applicable in Table 4.2.2(1) or fFollow Procedure for Measuring Airtightness of Duct Systems in ANSI/RESNET/ICC 380. The air handler shall be installed prior to testing.
Comment #19Page Number: 94Paragraph / Figure / Table / Note: Table 4.5.2(5) Default Eae ValuesComment Intent: ObjectionComment Type: TechnicalComment: Don’t delete these default Eae values for the Rated Home; the first two are the same values used for the Reference Home in Table 4.2.2.4(1). Reasonable defaults for shared systems are needed when they cannot be determined by the Rater. Proposed Change: Table 4.5.2(5) Default Eae Values System Type Eae Oil Boiler 330 Gas Boiler (serves one unit) 170 Gas Boiler (shared, in-unit baseboard) 220 Gas Boiler (shared, in-unit WLHP) 265 Gas Boiler (shared, in-unit fan coil) 438
Don’t delete these default Eae values for the Rated Home; the first two are the same values used for the Reference Home in Table 4.2.2.4(1).
Reasonable defaults for shared systems are needed when they cannot be determined by the Rater.
Table 4.5.2(5) Default Eae Values
System Type
Eae
Oil Boiler
330
Gas Boiler (serves one unit)
170
Gas Boiler (shared, in-unit baseboard)
220
Gas Boiler (shared, in-unit WLHP)
265
Gas Boiler (shared, in-unit fan coil)
438
Comment #20Page Number: A-2Comment Intent: ObjectionComment Type: TechnicalComment: While the language being added to the Exception in Appendix A, A-1.2, is intended as a clarification in response to an Interpretation Request, it is not adding the clarity it intends. The Committee should fine-tune the sentence to make it easier to understand. Proposed Change: A-1.2 Minimum Specific Application Requirements: Insulation installed in framed floor assemblies shall be in substantial and permanent contact with the subfloor. Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, pPerimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume.
While the language being added to the Exception in Appendix A, A-1.2, is intended as a clarification in response to an Interpretation Request, it is not adding the clarity it intends. The Committee should fine-tune the sentence to make it easier to understand.
Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, pPerimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume.
Comment #21Page Number: 24Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: Not an ObjectionComment Type: GeneralComment: This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Providers 24from New Jersey to Maine. If semi-conditioned walls are to be considered separately from above grade walls to exterior conditions, the U-factor should reference the ASHRAE table values for semi-conditioned space as opposed to the same U-factor table applied to exterior walls. Proposed Change: Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) ASHRAE 90.-2013 semi-conditioned space Table 5.5 Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100. Same as Rated Home
This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Providers 24from New Jersey to Maine.
If semi-conditioned walls are to be considered separately from above grade walls to exterior conditions, the U-factor should reference the ASHRAE table values for semi-conditioned space as opposed to the same U-factor table applied to exterior walls.
ASHRAE 90.-2013 semi-conditioned space Table 5.5
Comment #22Page Number: 26Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: Not an ObjectionComment Type: GeneralComment: This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Providers from New Jersey to Maine. We recommend clarifying the language regarding mechanical ventilation within the air exchange rate. As written, it may be misconstrued as the reference home having a balanced ventilation system. Proposed Change: Air exchange rate Specific Leakage Area (SLA)f = 0.00036 assuming no energy recovery, supplemented as necessary with balanced mechanical ventilation, to achieve the required Dwelling Unit total air exchange rate (Qtot).g, h In accordance with Standard ANSI/RESNET/ICC 380, obtain airtightness test results for: · Building enclosure (for Detached Dwelling Units) · Compartmentalization Boundary (for Attached Dwelling Units). For Attached Dwelling Units with airtightness test results ≤ 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be multiplied by reduction factor Aexti to determine the Infiltration rate. For Attached Dwelling Units with airtightness test results > 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modeled as the Infiltration rate. For residences without Dwelling Unit Mechanical Ventilation Systems, or without measured airflow, or where Aexti < 0.5 and the Mechanical Ventilation System is solely an Exhaust System, the Infiltration ratej shall be as determined above, but not less than 0.30 ACH. For residences with Dwelling Unit Mechanical Ventilation Systems, the total air exchange rate shall be the Infiltration ratej as determined above, in combinationh with the time-averaged Dwelling Unit Mechanical Ventilation System rate,g, k which shall be the value measured in accordance with Standard ANSI/RESNET/ICC 380. The Dwelling Unit Mechanical Ventilation System rate shall be increased as needed tTo ensure that the total air exchange rate is no less than Qtot = 0.03 x CFA + 7.5 x (Nbr+1) cfm, the Dwelling Unit Mechanical Ventilation System runtime operation shall first be increased, if possible, followed by increasing the airflow rate as needed.
This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Providers from New Jersey to Maine.
We recommend clarifying the language regarding mechanical ventilation within the air exchange rate. As written, it may be misconstrued as the reference home having a balanced ventilation system.
Air exchange rate
Specific Leakage Area (SLA)f = 0.00036 assuming no energy recovery, supplemented as necessary with balanced mechanical ventilation, to achieve the required Dwelling Unit total air exchange rate (Qtot).g, h
In accordance with Standard ANSI/RESNET/ICC 380, obtain airtightness test results for:
· Building enclosure (for Detached Dwelling Units)
· Compartmentalization Boundary (for Attached Dwelling Units).
For Attached Dwelling Units with airtightness test results ≤ 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be multiplied by reduction factor Aexti to determine the Infiltration rate. For Attached Dwelling Units with airtightness test results > 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modeled as the Infiltration rate.
For residences without Dwelling Unit Mechanical Ventilation Systems, or without measured airflow, or where Aexti < 0.5 and the Mechanical Ventilation System is solely an Exhaust System, the Infiltration ratej shall be as determined above, but not less than 0.30 ACH.
For residences with Dwelling Unit Mechanical Ventilation Systems, the total air exchange rate shall be the Infiltration ratej as determined above, in combinationh with the time-averaged Dwelling Unit Mechanical Ventilation System rate,g, k which shall be the value measured in accordance with Standard ANSI/RESNET/ICC 380. The Dwelling Unit Mechanical Ventilation System rate shall be increased as needed tTo ensure that the total air exchange rate is no less than Qtot = 0.03 x CFA + 7.5 x (Nbr+1) cfm, the Dwelling Unit Mechanical Ventilation System runtime operation shall first be increased, if possible, followed by increasing the airflow rate as needed.
Comment #23Page Number: 35Paragraph / Figure / Table / Note: Table 4.2.2(1) Notes: m.Comment Intent: Not an ObjectionComment Type: EditorialComment: This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Providers from New Jersey to Maine. The use of OEM specifications in determining fan wattage should be the last resort, and HVI data should be noted as an option. We also recommend that direct measurement be the first option listed, as direct measurement is considered to be best practice. Proposed Change: m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan[1], fan watts shall be the value observed either per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode . m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan[1], fan watts shall be determined through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode, the value observed through HVI specifications or the value observed througheither per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode.
The use of OEM specifications in determining fan wattage should be the last resort, and HVI data should be noted as an option. We also recommend that direct measurement be the first option listed, as direct measurement is considered to be best practice.
m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan[1], fan watts shall be the value observed either per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode .
m. Where Dwelling Unit Mechanical Ventilation Systems are specified but lack controls to either provide continuous or programmed operation, the system does not qualify as a Dwelling Unit Mechanical Ventilation System and the Rated Home shall be treated as a Dwelling Unit without a Dwelling Unit Mechanical Ventilation System. Where Dwelling Unit Mechanical Ventilation System controls have a standard On/Off switch to enable continuous ventilation, the controls shall only be treated as a Dwelling Unit Mechanical Ventilation System if the system is labeled clearly to identify the purpose of the switch and that the switch be set to “On” to enable Dwelling Unit Mechanical Ventilation. Dwelling Unit Mechanical Ventilation System fan watts shall be the value observed in the Rated Home for the highest airflow setting. Where not available, fan watts shall be based on Table 4.2.2(1a) for the given system. For systems other than Central Fan Integrated Supply (CFIS), where the airflow cannot be measured, the cfm used to determine fan watts shall be assumed to be equal to Qfan, as determined in accordance with Note g. of Table 4.2.2 (1), with a minimum of 15 cfm. For CFIS systems, the cfm used to determine fan watts shall be the larger of 400 cfm per 12 kBtu/h cooling capacity or 240 cfm per 12 kBtu/h heating capacity. For systems that consume energy beyond what is needed to operate the ventilation fan[1], fan watts shall be determined through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode, the value observed through HVI specifications or the value observed througheither per OEM specifications or through direct measurement in the Rated Home for the highest airflow setting in ventilation-only mode.
Comment #24Page Number: 38Paragraph / Figure / Table / Note: Table 4.2.2(1) Notes: x.Comment Intent: Not an ObjectionComment Type: EditorialComment: This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Provider from New Jersey to Maine. For clarity, we recommend adjusting the format of the final paragraph in note x, as two different items are being addressed with the new language. Proposed Change: x. When both of the following conditions are met and documented, duct leakage testing is not required. 1. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. 2. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A duct leakage to outside value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes Proposed: x. When both of the following conditions are met and documented, duct leakage testing is not required. 1. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. 2. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. Alternatively: A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A duct leakage to outside value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes
This comment is being issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 175 Raters and 9 Provider from New Jersey to Maine.
For clarity, we recommend adjusting the format of the final paragraph in note x, as two different items are being addressed with the new language.
1. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume.
2. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts.
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A duct leakage to outside value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes
Proposed:
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. Alternatively:
Comment #25Page Number: 38Paragraph / Figure / Table / Note: Footnote xComment Intent: ObjectionComment Type: TechnicalComment: My comment is specifically on the chosen DSE number "0.88" being applied to both the Rated homes heating and cooling systems efficiencies when the duct and air handler has complied with both of the visual verification requirements of footnote x. The energy penalty or loss of duct leakage is different for duct systems that are located inside or outside of the buildings continuous air barrier assembly. The 2006 IECC recognized this in the IECC table titled, “DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNS” that accompanies the proposed and reference home table for the Simulated Performance Alternative path. If the entirety of the duct system including the air handler cabinet is confirmed to be located inside conditioned space volume as defined by RESNET, then the likelihood of the system leaking to the outdoors is little to none. This has been proven time and again in the field by raters across the country. Therefore, the energy loss of duct leakage to outside would also be little. If testing is not performed for duct leakage to outside a small penalty should be assessed which this proposal provided. This proposal, continues to allow verified HVAC duct systems not to be tested for duct leakage to outdoors, and assess a DSE of 0.96 which equates to a 4% energy loss for the system. This has a moderate impact on the RESNET ERI score which is in better alignment with the penalty that should be associated for not testing. There needs to be a commonsense trade off / penalty for choosing not to test. Currently the "0.88" penalty is too much. If needed for compliance or to create a lower ERI score in the software, duct leakage could be tested to demonstrate a reduced leakage level below a 0.96 rate. Proposed Change: To calculate the energy impacts on the Rated Home, a DSE of 0.88 0.96 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
My comment is specifically on the chosen DSE number "0.88" being applied to both the Rated homes heating and cooling systems efficiencies when the duct and air handler has complied with both of the visual verification requirements of footnote x.
The energy penalty or loss of duct leakage is different for duct systems that are located inside or outside of the buildings continuous air barrier assembly. The 2006 IECC recognized this in the IECC table titled, “DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNS” that accompanies the proposed and reference home table for the Simulated Performance Alternative path.
If the entirety of the duct system including the air handler cabinet is confirmed to be located inside conditioned space volume as defined by RESNET, then the likelihood of the system leaking to the outdoors is little to none. This has been proven time and again in the field by raters across the country. Therefore, the energy loss of duct leakage to outside would also be little. If testing is not performed for duct leakage to outside a small penalty should be assessed which this proposal provided.
This proposal, continues to allow verified HVAC duct systems not to be tested for duct leakage to outdoors, and assess a DSE of 0.96 which equates to a 4% energy loss for the system. This has a moderate impact on the RESNET ERI score which is in better alignment with the penalty that should be associated for not testing. There needs to be a commonsense trade off / penalty for choosing not to test. Currently the "0.88" penalty is too much.
If needed for compliance or to create a lower ERI score in the software, duct leakage could be tested to demonstrate a reduced leakage level below a 0.96 rate.
To calculate the energy impacts on the Rated Home, a DSE of 0.88 0.96 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
Comment #26Page Number: 38Paragraph / Figure / Table / Note: Footnote xComment Intent: ObjectionComment Type: TechnicalComment: The addition of the word “OR” has been added between tow different choices. I do not believe that these choices are related and therefore the work “AND should not be used. In the 2015 IECC,Joe Lstiburek introduced new language to Section R402.2.8 Floors, which highlighted the fact that different or new insulation techniques are available for assemblies adjacent to unconditioned space that also often have duct within them. In the 2021 IECC this floor section was rewritten to make the 2015 IECC exception more understandable and thus executable in the field. In addition, Section R403.3.2, “Ducts located in conditioned space” was amended to specifically address ductwork that is located within assemblies, as we have duct that is clearly inside and clearly outside but never defined duct that is within the buildings thermal envelope. With this new definition there are new possibilities of utilizing the duct leakage exceptions 4CFM/100sqft of conditioned floor area allowance when modeling a home in the software’s. The allowance is not saying that the ducts are not leaking, rather a reasonable penalty is associated with ducts in these locations that have been installed correctly. This allowance/penalty would be reflected on the RESNET ERI score but would not impact code compliance as it is in alignment with the allowable leakage rate. Proposed Change: To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. OR A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or has been installed in Unconditioned Space Volumes Or ductwork has been installed per section R403.3.2, “Ducts located in conditioned space” of the 2021 IECC for ducts to be considered inside a conditioned space
The addition of the word “OR” has been added between tow different choices. I do not believe that these choices are related and therefore the work “AND should not be used.
In the 2015 IECC,Joe Lstiburek introduced new language to Section R402.2.8 Floors, which highlighted the fact that different or new insulation techniques are available for assemblies adjacent to unconditioned space that also often have duct within them. In the 2021 IECC this floor section was rewritten to make the 2015 IECC exception more understandable and thus executable in the field. In addition, Section R403.3.2, “Ducts located in conditioned space” was amended to specifically address ductwork that is located within assemblies, as we have duct that is clearly inside and clearly outside but never defined duct that is within the buildings thermal envelope.
With this new definition there are new possibilities of utilizing the duct leakage exceptions 4CFM/100sqft of conditioned floor area allowance when modeling a home in the software’s. The allowance is not saying that the ducts are not leaking, rather a reasonable penalty is associated with ducts in these locations that have been installed correctly. This allowance/penalty would be reflected on the RESNET ERI score but would not impact code compliance as it is in alignment with the allowable leakage rate.
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. OR A value of 4 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or has been installed in Unconditioned Space Volumes Or ductwork has been installed per section R403.3.2, “Ducts located in conditioned space” of the 2021 IECC for ducts to be considered inside a conditioned space
Comment #27Page Number: 4Paragraph / Figure / Table / Note: DefinitionsComment Intent: Not an ObjectionComment Type: EditorialComment: The definition of a bathroom should be consistent among standards and programs, especially given that there are implications for both water use and ventilation. ASHRAE 62.2, for example, defines a bathroom as having a tub, shower, spa or other similar source of moisture. Proposed Change: Bathroom – A room containing with at least one sink, and at least one toilet, and a bathtub, shower, spa, or other similar source of moisture.
The definition of a bathroom should be consistent among standards and programs, especially given that there are implications for both water use and ventilation. ASHRAE 62.2, for example, defines a bathroom as having a tub, shower, spa or other similar source of moisture.
Bathroom – A room containing with at least one sink, and at least one toilet, and a bathtub, shower, spa, or other similar source of moisture.
Comment #28Page Number: 23Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: Not an ObjectionComment Type: TechnicalComment: Insulation in the reference home should be GIII. This represents a more realistic take on the average install from 2006. The U-factors of all assemblies should be adjusted accordingly. Proposed Change: Above-grade walls separating Conditioned Space Volume from outdoor environment Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) at an installation grade of GIII Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100.Same as Rated Home Same as Rated Home Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume , Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) at an installation grade of GIII Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100. Same as Rated Home Conditioned basement walls Type: same as Rated Home Gross Area: same as Rated Home UR-FactorValue: from Table 4.2.2(2) at an installation grade of GIII with the insulation layer on the interior side of walls Same as Rated Home Same as Rated Home Same as Rated Home Floors over Unconditioned Space Volume, Non-Freezing Space, Unrated Heated Space, or Multifamily Buffer Boundary or outdoor environment Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) at an installation grade of GIII Same as Rated Home Same as Rated Home Same as Rated Home Floors over outdoor environment Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) at an installation grade of GIII Same as Rated Home Same as Rated Home Same as Rated Home Ceilings above Conditioned Space Volume and below an Attic, Unconditioned Space Volume, Non-Freezing Space, Unrated Heated Space, or Multifamily Buffer Boundary Type: wood frame Gross Area: same as Rated Home ceiling area U-Factor: from Table 4.2.2(2) at an installation grade of GIII Same as Rated Home Same as Rated Home Same as Rated Home Roofs Type: composition shingle on wood sheathing Gross Area: same as Rated Home Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Values from Table 4.2.2(45) shall be used to determine Solar Absorptance, except where test data are provided for roof surface in accordance with ANSI/CRRC S100. Emittance values provided by the roofing manufacturer in accordance with ANSI/CRRC S100 shall be used when available. In cases where the appropriate data are not known, same as the Reference Home. Attics Type: vented with aperture = 1ft2 per 300 ft2 ceiling area Attic roof assemblies shall be uninsulated, while the ceiling below the Attic shall be insulated according to Table 4.2.2(2) at an installation grade of GIII Same as Rated Home Same as Rated Home Foundations Type: same as Rated Home Gross Area: same as Rated Home U-Factor / R-Value: from Table 4.2.2(2) at an installation grade of GIII Same as Rated Home Same as Rated Home Same as Rated Home Crawlspaces Type: vented with net free vent aperture = 1ft2 per 150 ft2 of crawlspace floor area. Crawlspace walls shall be uninsulated, while the floor above the crawlspace shall be insulated according to Table 4.2.2(2) as a “Floor over Unconditioned Space at an installation grade of GIII Volume.” a U-Factor: from Table 4.2.2(2) for floors over Unconditioned Space Volume or outdoor environment, at an installation grade of GIII Same as the Rated Home, but not less net free Ventilation area than the Reference Home unless an Approved ground cover in accordance with IRC 408.3.1 is used, in which case, the same net free Ventilation area as the Rated Home down to a minimum net free vent area of 1ft2 per 1,500 ft2 of crawlspace floor area. Same as Rated Home
Insulation in the reference home should be GIII. This represents a more realistic take on the average install from 2006. The U-factors of all assemblies should be adjusted accordingly.
Above-grade walls separating Conditioned Space Volume from outdoor environment
U-Factor: from Table 4.2.2(2) at an installation grade of GIII
Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume , Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space
Conditioned basement walls
Type: same as Rated Home
UR-FactorValue: from Table 4.2.2(2) at an installation grade of GIII with the insulation layer on the interior side of walls
Floors over Unconditioned Space Volume, Non-Freezing Space, Unrated Heated Space, or Multifamily Buffer Boundary or outdoor environment
Floors over outdoor environment
Ceilings above Conditioned Space Volume and below an Attic, Unconditioned Space Volume, Non-Freezing Space, Unrated Heated Space, or Multifamily Buffer Boundary
Gross Area: same as Rated Home ceiling area
Roofs
Type: composition shingle on wood sheathing
Values from Table 4.2.2(45) shall be used to determine Solar Absorptance, except where test data are provided for roof surface in accordance with ANSI/CRRC S100.
Emittance values provided by the roofing manufacturer in accordance with ANSI/CRRC S100 shall be used when available. In cases where the appropriate data are not known, same as the Reference Home.
Attics
Type: vented with aperture = 1ft2 per 300 ft2 ceiling area
Attic roof assemblies shall be uninsulated, while the ceiling below the Attic shall be insulated according to Table 4.2.2(2) at an installation grade of GIII
Foundations
U-Factor / R-Value: from Table 4.2.2(2) at an installation grade of GIII
Crawlspaces
Type: vented with net free vent aperture = 1ft2 per 150 ft2 of crawlspace floor area.
Crawlspace walls shall be uninsulated, while the floor above the crawlspace shall be insulated according to Table 4.2.2(2) as a “Floor over Unconditioned Space at an installation grade of GIII
Volume.” a
U-Factor: from Table 4.2.2(2) for floors over Unconditioned Space Volume or outdoor environment, at an installation grade of GIII
Same as the Rated Home, but not less net free Ventilation area than the Reference Home unless an Approved ground cover in accordance with IRC 408.3.1 is used, in which case, the same net free Ventilation area as the Rated Home down to a minimum net free vent area of 1ft2 per 1,500 ft2 of crawlspace floor area.
Comment #29Page Number: 24Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: Not an ObjectionComment Type: EditorialComment: Including Unconditioned Space Volume in the categorization of "semi-conditioned" spaces may have unintended consequences, as USV includes insulated, non-conditioned attic spaces. Proposed Change: Above-grade walls separating Conditioned Space Volume from Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space Type: wood frame Gross Area: same as Rated Home U-Factor: from Table 4.2.2(2) Solar Absorptance = 0.75 Emittance = 0.90 Same as Rated Home Same as Rated Home Same as Rated Home Values from Table 4.2.2(4) shall be used to determine Solar Absorptance, except where test data are provided for wall surface in accordance with ANSI/CRRC S100. Same as Rated Home Ceilings above Conditioned Space Volume and below an Attic, Unconditioned Space Volume, Non-Freezing Space, Unrated Heated Space, or Multifamily Buffer Boundary Type: wood frame Gross Area: same as Rated Home ceiling area U-Factor: from Table 4.2.2(2) Same as Rated Home Same as Rated Home Same as Rated Home
Including Unconditioned Space Volume in the categorization of "semi-conditioned" spaces may have unintended consequences, as USV includes insulated, non-conditioned attic spaces.
Comment #30Page Number: 26Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: Not an ObjectionComment Type: TechnicalComment: When defining the air exchange rate for the reference home, we recommend changing the formula from SLA to a more recognizable metric-- cfm50/shell or ACH50. Proposed Change: Air exchange rate Specific Leakage Area (SLA)f = 0.00036 For Attached Dwelling Units, 0.30 cfm50 per ft2 For Residences, 7 ACH50 assuming no energy recovery, supplemented as necessary with balanced mechanical ventilation to achieve the required Dwelling Unit total air exchange rate (Qtot).g, h In accordance with Standard ANSI/RESNET/ICC 380, obtain airtightness test results for: · Building enclosure (for Detached Dwelling Units) · Compartmentalization Boundary (for Attached Dwelling Units). For Attached Dwelling Units with airtightness test results ≤ 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be multiplied by reduction factor Aexti to determine the Infiltration rate. For Attached Dwelling Units with airtightness test results > 0.30 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modeled as the Infiltration rate. For residences without Dwelling Unit Mechanical Ventilation Systems, or without measured airflow, or where Aexti < 0.5 and the Mechanical Ventilation System is solely an Exhaust System, the Infiltration ratej shall be as determined above, but not less than 0.30 ACH. For residences with Dwelling Unit Mechanical Ventilation Systems, the total air exchange rate shall be the Infiltration ratej as determined above, in combinationh with the time-averaged Dwelling Unit Mechanical Ventilation System rate,g, k which shall be the value measured in accordance with Standard ANSI/RESNET/ICC 380. The Dwelling Unit Mechanical Ventilation System rate shall be increased as needed tTo ensure that the total air exchange rate is no less than Qtot = 0.03 x CFA + 7.5 x (Nbr+1) cfm, the Dwelling Unit Mechanical Ventilation System runtime operation shall first be increased, if possible, followed by increasing the airflow rate as needed.
When defining the air exchange rate for the reference home, we recommend changing the formula from SLA to a more recognizable metric-- cfm50/shell or ACH50.
Specific Leakage Area (SLA)f = 0.00036
For Attached Dwelling Units, 0.30 cfm50 per ft2
For Residences, 7 ACH50
assuming no energy recovery, supplemented as necessary with balanced mechanical ventilation to achieve the required Dwelling Unit total air exchange rate (Qtot).g, h
Comment #31Page Number: 37Paragraph / Figure / Table / Note: Table 4.2.2(1) Notes: tComment Intent: Not an ObjectionComment Type: EditorialComment: Where there is a shared storage water heater, the usage should not only be divided by the number of units, but prorated based on the number of bedrooms as other shared equipment is throughout the standard. Proposed Change: t. For a Rated Home with a nonstorage-type water heater or where a shared water heater provides service hot water to the Rated Home, a 40-gallon storage-type water heater of the same fuel as the proposed water heater shall be assumed for the Energy Rating Reference Home. For a Rated Home with a shared storage water heater, its tank losses shall be divided by the number of dwelling units served by the water heater ,prorated based on # bedrooms +1. For tankless water heaters with an Energy Factor, EF shall be multiplied by 0.92 for Rated Home calculations. For tankless water heaters with a Uniform Energy Factor, UEF shall be multiplied by 0.94 for Rated Home calculations. For a Rated Home without a proposed water heater, a 40-gallon storage-type water heater of the same fuel as the predominant fuel type used for the heating system(s) shall be assumed for both the Rated and Energy Rating Reference Homes. In both cases, the Energy Factor of the water heater shall be as prescribed for the Energy Rating Reference Home water heater by Table 4.2.2(1). Where the Rated Home has multiple water heaters, the Energy Rating Reference Home shall have a 40-gallon storage-type water heater of the same fuel type as the predominant water heating type in the Rated Home.
Where there is a shared storage water heater, the usage should not only be divided by the number of units, but prorated based on the number of bedrooms as other shared equipment is throughout the standard.
t. For a Rated Home with a nonstorage-type water heater or where a shared water heater provides service hot water to the Rated Home, a 40-gallon storage-type water heater of the same fuel as the proposed water heater shall be assumed for the Energy Rating Reference Home. For a Rated Home with a shared storage water heater, its tank losses shall be divided by the number of dwelling units served by the water heater ,prorated based on # bedrooms +1. For tankless water heaters with an Energy Factor, EF shall be multiplied by 0.92 for Rated Home calculations. For tankless water heaters with a Uniform Energy Factor, UEF shall be multiplied by 0.94 for Rated Home calculations. For a Rated Home without a proposed water heater, a 40-gallon storage-type water heater of the same fuel as the predominant fuel type used for the heating system(s) shall be assumed for both the Rated and Energy Rating Reference Homes. In both cases, the Energy Factor of the water heater shall be as prescribed for the Energy Rating Reference Home water heater by Table 4.2.2(1). Where the Rated Home has multiple water heaters, the Energy Rating Reference Home shall have a 40-gallon storage-type water heater of the same fuel type as the predominant water heating type in the Rated Home.
Comment #32Page Number: 38Paragraph / Figure / Table / Note: Table 4.2.2(1) Notes: xComment Intent: Not an ObjectionComment Type: EditorialComment: The proposed rate of leakage to outside for ductwork contained within the CFA/CSV is punitively high. Proposed Change: x. When both of the following conditions are met and documented, duct leakage testing is not required. 1. At a pre-drywall stage of construction, 100 percent of the ductwork and airhandler shall be visible and visually verified to be contained inside the Conditioned Space Volume. At a final stage of construction, ductwork that is visible and the air handler shall be verified again to be contained in the Conditioned Space Volume. 2. At a pre-drywall stage of construction, the ductwork shall be visually verified to be 100 percent fully ducted with no building cavities used as supply or return ducts. To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft. A duct leakage to outside value of 4 2 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
The proposed rate of leakage to outside for ductwork contained within the CFA/CSV is punitively high.
To calculate the energy impacts on the Rated Home, a DSE of 0.88 shall be applied to both the heating and cooling system efficiencies. A DSE of 1.0 may be applied if the total supply duct length of the system, including all supply trunks and branches, is ≤ 10 ft.
A duct leakage to outside value of 4 2 cfm per 100 square feet of Conditioned Floor Area may be modeled for duct leakage to outside if no ductwork is contained within envelope assemblies adjacent to the exterior or Unconditioned Space Volumes.
Comment #33Page Number: 43Paragraph / Figure / Table / Note: 4.2.2.1.2Comment Intent: Not an ObjectionComment Type: EditorialComment: The assembly-specific framing fraction minimum of 10% is unrealistically low. Proposed Change: 1.1.1.1. All enclosure element Framing Fractions shall be in accordance with Table 4.2.2(5). A framing fraction shall be designated for each segment of framed wall, floor, and ceiling assembly that separates one space type from another type or the exterior[1]. A wall segment is defined as a planar section bounded side-to-side by the wall corners and top-to-bottom by the top plate and bottom plate. A floor segment is defined as a planar section bounded by rim or band joists. A ceiling segment is defined as a planar section bounded by exterior top plates, eves, or gables. If different framing fractions are designated for different segments of the framed wall, floor, or ceiling assembly, then multiple entries are permitted to be entered into the rating software. Alternatively, the entire assembly can be modeled with the highest designated framing fraction. For ratings where the framing is not visible at the time of the site inspection, the framing fractions shall equal the highest default framing fraction for the assembly component listed in Table 4.2.2(5). For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for their framing spacing listed in Table 4.2.2(5). Wall assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2(5), unless the conditions in Section 4.2.2.1.1 or Section 4.2.2.1.2 have been met. 4.2.2.1.1 The default framing fractions for the Advanced framing type are permitted to be used if the wall segment complies with all the following conditions: 4.2.2.1.1.1 Corners of cavities shall be completely filled with ≥ R-6[2] insulation. 4.2.2.1.1.2 Intersections with interior walls shall be insulated to the same R-value as the remainder of the wall assembly.[3] 4.2.2.1.1.3 Headers of frame walls shall be insulated ≥ R-3 for 2x4 framing or equivalent cavity width, and ≥ R-5 for all other assemblies[4], where the R-value requirement refers to the manufacturer’s nominal insulation value[5]. 4.2.2.1.1.4 The framing shall be limited at all windows & doors to one pair of king studs, plus one pair of jack studs per window opening to support the header and sill. 4.2.2.1.2 The assembly-specific framing fraction or 10%, whichever is larger, is permitted to be used if a framing plan with the design framing fraction and a professional engineer’s stamp has been obtained and the framing plan has been verified to match the actual assembly in field.[6]
The assembly-specific framing fraction minimum of 10% is unrealistically low.
1.1.1.1. All enclosure element Framing Fractions shall be in accordance with Table 4.2.2(5). A framing fraction shall be designated for each segment of framed wall, floor, and ceiling assembly that separates one space type from another type or the exterior[1].
A wall segment is defined as a planar section bounded side-to-side by the wall corners and top-to-bottom by the top plate and bottom plate. A floor segment is defined as a planar section bounded by rim or band joists. A ceiling segment is defined as a planar section bounded by exterior top plates, eves, or gables. If different framing fractions are designated for different segments of the framed wall, floor, or ceiling assembly, then multiple entries are permitted to be entered into the rating software. Alternatively, the entire assembly can be modeled with the highest designated framing fraction.
For ratings where the framing is not visible at the time of the site inspection, the framing fractions shall equal the highest default framing fraction for the assembly component listed in Table 4.2.2(5).
For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for their framing spacing listed in Table 4.2.2(5). Wall assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2(5), unless the conditions in Section 4.2.2.1.1 or Section 4.2.2.1.2 have been met.
4.2.2.1.1 The default framing fractions for the Advanced framing type are permitted to be used if the wall segment complies with all the following conditions:
4.2.2.1.1.1 Corners of cavities shall be completely filled with ≥ R-6[2] insulation.
4.2.2.1.1.2 Intersections with interior walls shall be insulated to the same R-value as the remainder of the wall assembly.[3]
4.2.2.1.1.3 Headers of frame walls shall be insulated ≥ R-3 for 2x4 framing or equivalent cavity width, and ≥ R-5 for all other assemblies[4], where the R-value requirement refers to the manufacturer’s nominal insulation value[5].
4.2.2.1.1.4 The framing shall be limited at all windows & doors to one pair of king studs, plus one pair of jack studs per window opening to support the header and sill.
4.2.2.1.2 The assembly-specific framing fraction or 10%, whichever is larger, is permitted to be used if a framing plan with the design framing fraction and a professional engineer’s stamp has been obtained and the framing plan has been verified to match the actual assembly in field.[6]
Comment #34Page Number: 73Paragraph / Figure / Table / Note: Table 4.3.1(1)Comment Intent: Not an ObjectionComment Type: EditorialComment: Including Unconditioned Space Volume in the categorization of "semi-conditioned" spaces may have unintended consequences, as USV includes insulated, non-conditioned attic spaces. Proposed Change: Above-grade walls separating Conditioned Space Volume from outdoor environment, Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space Type: Same as Rated Home. If more than one type, maintain same proportional coverage for each type, excluding any garage wall, Multifamily Buffer Boundary wall, adiabatic wall and sealed attic gable-end wall areasincluding only wall area separating Conditioned Space Volume and the outdoor environment. U-Factor: Same as Rated Home Solar Absorptance: Same as Rated Home Emittance: Same as Rated Home Ceilings above Conditioned Space Volume and below an Attic, Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, Non-Freezing Space, or outdoor environment Type: Same as Rated Home. If more than one type, maintain same proportional coverage for each type. Gross projected footprint area: 1200 ft2 U-Factor: Same as Rated Home
Above-grade walls separating Conditioned Space Volume from outdoor environment, Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, or Non-Freezing Space
Type: Same as Rated Home. If more than one type, maintain same proportional coverage for each type, excluding any garage wall, Multifamily Buffer Boundary wall, adiabatic wall and sealed attic gable-end wall areasincluding only wall area separating Conditioned Space Volume and the outdoor environment.
U-Factor: Same as Rated Home
Solar Absorptance: Same as Rated Home
Emittance: Same as Rated Home
Ceilings above Conditioned Space Volume and below an Attic, Unconditioned Space Volume, Unrated Heated Space, Multifamily Buffer Boundary, Non-Freezing Space, or outdoor environment
Type: Same as Rated Home. If more than one type, maintain same proportional coverage for each type.
Gross projected footprint area: 1200 ft2
Comment #35Page Number: A-2Paragraph / Figure / Table / Note: A-1.2 Minimum Specific Application Requirements:Comment Intent: Not an ObjectionComment Type: EditorialComment: New language within the exception for Insulation at framed floor assemblies was unclear. We recommend simplifying for clarity. Proposed Change: A-1.2 Minimum Specific Application Requirements: 1. Insulation installed in framed floor assemblies shall be in substantial and permanent contact with the subfloor. Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, perimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume shall be the same depth of the floor cavity.
New language within the exception for Insulation at framed floor assemblies was unclear. We recommend simplifying for clarity.
1. Insulation installed in framed floor assemblies shall be in substantial and permanent contact with the subfloor.
Exception: The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-Value in Table 402.1.2 of the International Energy Conservation Code (IECC) and that extends from the bottom to the top of all perimeter floor framing members. Where the floor perimeter meets an exterior envelope wall, perimeter floor insulation is not required to extend vertically from the bottom to the top of framing members that separate the Unconditioned Space Volume of the floor cavity from the Conditioned Space Volume shall be the same depth of the floor cavity.
Comment #36Page Number: B-3-B-77Paragraph / Figure / Table / Note: Normative Appendix BComment Intent: Not an ObjectionComment Type: EditorialComment: Where language has been modified to "determine and record" throughout the appendix, we recommend clarifying what methods of recording data are considered acceptable. An example is given below. Proposed Change: Foundation type DetermineDetermine and record whether foundation is a crawlspace, or basement, slab on grade or combination and whether it meets the criteria for Conditioned Space Volume, Unconditioned Space Volume, Unrated Conditioned Space, or Infiltration Volume. Use the definitions in Section 3 to determinedetermine and record via photo documentation whether a crawlspace or basement is Conditioned Space Volume, Unconditioned Space Volume, Unrated Conditioned Space, or Infiltration Volume.
Where language has been modified to "determine and record" throughout the appendix, we recommend clarifying what methods of recording data are considered acceptable. An example is given below.
Foundation type
DetermineDetermine and record whether foundation is a crawlspace, or basement, slab on grade or combination and whether it meets the criteria for Conditioned Space Volume, Unconditioned Space Volume, Unrated Conditioned Space, or Infiltration Volume.
Use the definitions in Section 3 to determinedetermine and record via photo documentation whether a crawlspace or basement is Conditioned Space Volume, Unconditioned Space Volume, Unrated Conditioned Space, or Infiltration Volume.
Comment #37Page Number: 43-44Paragraph / Figure / Table / Note: Section 4.2.2.1 and Table 4.2.2(5)Comment Intent: ObjectionComment Type: GeneralComment: Overall, I believe the proposed edits in these sections will improve the standard but have the following suggestions for improvement: The table could be revised for clarity by removing redundant information, such as the framing spacing being listed twice. The proposed edits define Standard and Advanced framing types for walls, but do not define the wall framing type “Structurally Insulated Panels” or those for ceilings (i.e., standard trusses, raised heel, and common framing). If these framing types are retained, they should also be defined. Alternatively, they should be deleted. It is unclear why “raised heel” is considered a framing type that would impact the framing fraction. Instead this framing detail would likely only impact the amount of insulation in the ceiling, not the framing fraction. Consider deleting this framing type. Proposed Change: Revise Section 4.2.2.1 as follows: “For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for its their framing spacing listed in Table 4.2.2(5). Wall and ceiling assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2(5), unless the conditions in Section 4.2.2.1.1, or Section 4.2.2.1.2, or Section 4.2.2.1.3 have been met for walls or Section 4.2.2.1.4 for ceilings.” Add a new Section 4.2.2.1.3 that includes a definition for a SIP wall and Section 4.2.2.1.4 that includes a definition of Common Framing. For improved clarity, replace Table 4.2.2(5) with the following table: Assembly Component Framing Type Framing Spacing (Inches On-Center) Default Framing Fraction (% Area) Wall Standard 16 25% Standard 24 22% Advanced 16 19% Advanced 24 16% Structurally Insulated Panel 48 10% Floor n/a 16 13% n/a 24 10% Ceiling Standard 16 14% Standard 24 11% Common Framing 16 13% Common Framing 24 9%
Overall, I believe the proposed edits in these sections will improve the standard but have the following suggestions for improvement:
Revise Section 4.2.2.1 as follows: “For ratings where the framing is visible at the time of the site inspection, floor and ceiling assemblies shall use the default framing fractions for its their framing spacing listed in Table 4.2.2(5). Wall and ceiling assemblies shall use the default framing fractions for their framing spacing and the Standard framing type listed in Table 4.2.2(5), unless the conditions in Section 4.2.2.1.1, or Section 4.2.2.1.2, or Section 4.2.2.1.3 have been met for walls or Section 4.2.2.1.4 for ceilings.”
Add a new Section 4.2.2.1.3 that includes a definition for a SIP wall and Section 4.2.2.1.4 that includes a definition of Common Framing.
For improved clarity, replace Table 4.2.2(5) with the following table:
Assembly Component
Framing Type
Framing Spacing
(Inches On-Center)
Default Framing Fraction
(% Area)
Wall
Standard
16
25%
24
22%
Advanced
19%
16%
Structurally Insulated Panel
48
10%
Floor
n/a
13%
Ceiling
14%
11%
Common Framing
9%
Comment #38Page Number: 4Paragraph / Figure / Table / Note: DefinitionsComment Intent: Not an ObjectionComment Type: EditorialComment: Std. 380-2022 proposed to include the following informative footnote for the definition of Conditioned Floor Area: "(Informative Note) Conditioned Space Volume that is intended for human activities (e.g., for living, sleeping, dining, or cooking; as well as toilets, closets, halls, utility areas, and laundry areas) and above the main Dwelling Unit, such as in a ‘Cape Cod’ home, is not considered attic space and can be included in the Conditioned Floor Area." Consider adding the same informative footnote to the definition of Attic for improved clarity. Proposed Change: "Attic – A space volume directly below the roof assembly that is not included in the Conditioned Floor Area. Attics may be either vented or air sealed. (Informative Note) Conditioned Space Volume that is intended for human activities (e.g., for living, sleeping, dining, or cooking; as well as toilets, closets, halls, utility areas, and laundry areas) and above the main Dwelling Unit, such as in a ‘Cape Cod’ home, is not considered attic space and can be included in the Conditioned Floor Area."
Std. 380-2022 proposed to include the following informative footnote for the definition of Conditioned Floor Area: "(Informative Note) Conditioned Space Volume that is intended for human activities (e.g., for living, sleeping, dining, or cooking; as well as toilets, closets, halls, utility areas, and laundry areas) and above the main Dwelling Unit, such as in a ‘Cape Cod’ home, is not considered attic space and can be included in the Conditioned Floor Area."
Consider adding the same informative footnote to the definition of Attic for improved clarity.
"Attic – A space volume directly below the roof assembly that is not included in the Conditioned Floor Area. Attics may be either vented or air sealed.
(Informative Note) Conditioned Space Volume that is intended for human activities (e.g., for living, sleeping, dining, or cooking; as well as toilets, closets, halls, utility areas, and laundry areas) and above the main Dwelling Unit, such as in a ‘Cape Cod’ home, is not considered attic space and can be included in the Conditioned Floor Area."
Comment #39Page Number: 46, 47Paragraph / Figure / Table / Note: Section 4.2.2.3.1.1, 4.2.2.3.1.2, 4.2.2.3.1.3Comment Intent: Not an ObjectionComment Type: TechnicalComment: The phrase "Air-Source" has been proposed to be added before the phrase "Heat Pump" in Sections 4.2.2.3.1.1, 4.2.2.3.1.2, 4.2.2.3.1.3. In fact, the installation quality configurations defined in these three sections should be applied to all heat pumps, not just air-source heat pumps. Therefore, the phrase "Air-Source" should not be added, after all. Proposed Change: Do not add the phrase "Air-Source" in Sections 4.2.2.3.1.1, 4.2.2.3.1.2, 4.2.2.3.1.3.
The phrase "Air-Source" has been proposed to be added before the phrase "Heat Pump" in Sections 4.2.2.3.1.1, 4.2.2.3.1.2, 4.2.2.3.1.3. In fact, the installation quality configurations defined in these three sections should be applied to all heat pumps, not just air-source heat pumps. Therefore, the phrase "Air-Source" should not be added, after all.
Do not add the phrase "Air-Source" in Sections 4.2.2.3.1.1, 4.2.2.3.1.2, 4.2.2.3.1.3.
Comment #40Page Number: 47Paragraph / Figure / Table / Note: Section 4.2.2.3.2Comment Intent: Not an ObjectionComment Type: TechnicalComment: The word "Furnace" has been proposed to be added to Section 4.2.2.3.2. However, this section defines how to modify the capacity and efficiency of heat pumps and AC's based on the installation quality. Because the capacity and efficiency of furnaces should not be modified using these equations, the word "Furnace" should not be added. Proposed Change: Do not add the word "Furnace" to Section 4.2.2.3.2.
The word "Furnace" has been proposed to be added to Section 4.2.2.3.2. However, this section defines how to modify the capacity and efficiency of heat pumps and AC's based on the installation quality. Because the capacity and efficiency of furnaces should not be modified using these equations, the word "Furnace" should not be added.
Do not add the word "Furnace" to Section 4.2.2.3.2.
Comment #41Page Number: B-16 and B-23Paragraph / Figure / Table / Note: Appendix B - Wall Assembly & Roof/Ceiling Assembly - Framing MembersComment Intent: ObjectionComment Type: GeneralComment: The proposed edits in Section 4.2.2.1 include a wall framing type for SIPs. However, in Appendix B, the On-Site Inspection Protocol only defines how the verifier should assess the framing type for Advanced framing and if using a framing plan. If the SIP framing type is retained, then this section should be edited to include instructions for assessing the SIP framing type. The proposed edits in Section 4.2.2.1 include various ceiling framing types (i.e., standard trusses, raised heel, common framing). However, in Appendix B, the On-Site Inspection Protocol only directs the verifier to record the framing member size and spacing. If multiple ceiling framing types are retained, then this section should be edited to direct the veifier to also record the ceiling framing type.
The proposed edits in Section 4.2.2.1 include a wall framing type for SIPs. However, in Appendix B, the On-Site Inspection Protocol only defines how the verifier should assess the framing type for Advanced framing and if using a framing plan. If the SIP framing type is retained, then this section should be edited to include instructions for assessing the SIP framing type.
The proposed edits in Section 4.2.2.1 include various ceiling framing types (i.e., standard trusses, raised heel, common framing). However, in Appendix B, the On-Site Inspection Protocol only directs the verifier to record the framing member size and spacing. If multiple ceiling framing types are retained, then this section should be edited to direct the veifier to also record the ceiling framing type.
Comment #42Page Number: 80Paragraph / Figure / Table / Note: Section 4.4.5Comment Intent: Not an ObjectionComment Type: TechnicalComment: Section 4.4.5 defines, in part, how to calculate the fan energy of a ground-source heat pump connected to a duct system. Elsewhere in the standard, and in Std. 310, Blower Fan Efficiency is defined for air conditioners, furnaces, and heat pumps. It's unclear whether these two sections conflict with each, given that both apply to ground-source heat pumps with blower fans. Proposed Change: While no specific edit is proposed at this time, this comment has been submitted so that this possible conflict can be further assessed and resolved, if needed.
Section 4.4.5 defines, in part, how to calculate the fan energy of a ground-source heat pump connected to a duct system. Elsewhere in the standard, and in Std. 310, Blower Fan Efficiency is defined for air conditioners, furnaces, and heat pumps. It's unclear whether these two sections conflict with each, given that both apply to ground-source heat pumps with blower fans.
While no specific edit is proposed at this time, this comment has been submitted so that this possible conflict can be further assessed and resolved, if needed.