The following comments have been submitted:
Comment #1Page Number: 22, 24, 56Paragraph / Figure / Table / Note: Table 4.2.2(1) Specifications for the Energy Rating Reference and Rated Homes, Table 4.3.1(1) Configuration of Index Adjustment DesignComment Intent: ObjectionComment Type: TechnicalComment: A key RESNET goal/accomplishment is the inclusion of the ERI as an IECC compliance path. However, when RESNET’s 301 conflicts with a specific IECC requirement for computing the ERI, then 301 creates confusion. This draft 301 conflicts with the IECC requirement for ERI ventilation rate. 301 should be consistent with the IECC requirement. Otherwise there will usually be two different ERI scores for each house, one with the 301 ventilation rate and one with the IRC/IECC ventilation rate. Both will have the same name, “ERI”. Try explaining that to the code enforcement staff. Or to home buyers. The IECC’s required ERI ventilation rate is: ventilation (cfm) = (0.01 x Floor Area (sq ft)) + [7.5 x (number of bedrooms + 1) ] Proposed Change: Make this change on pages 22, 24, and 56 0.03 0.01 x CFA + 7.5 x (Nbr+1) cfm
A key RESNET goal/accomplishment is the inclusion of the ERI as an IECC compliance path. However, when RESNET’s 301 conflicts with a specific IECC requirement for computing the ERI, then 301 creates confusion.
This draft 301 conflicts with the IECC requirement for ERI ventilation rate. 301 should be consistent with the IECC requirement. Otherwise there will usually be two different ERI scores for each house, one with the 301 ventilation rate and one with the IRC/IECC ventilation rate. Both will have the same name, “ERI”. Try explaining that to the code enforcement staff. Or to home buyers.
The IECC’s required ERI ventilation rate is:
ventilation (cfm) = (0.01 x Floor Area (sq ft)) + [7.5 x (number of bedrooms + 1) ]
Make this change on pages 22, 24, and 56
0.03 0.01 x CFA + 7.5 x (Nbr+1) cfm
Comment #2Page Number: 4Paragraph / Figure / Table / Note: 3.2 DefinitionsComment Intent: Not an ObjectionComment Type: EditorialComment: The definition for bedroom should use the terminology of the International Residential Code, Scope where it addresses buildings that are not considered " multi-family". Proposed Change: Bedroom – AFor one- and two-family Dwellings and Townhouses or buildings with one or two units, a room or space 70 square feet of floor area or greater, with egress window and closet, used or intended to be used for sleeping. A "den," "library," "home office" with a closet, egress window, and 70 square feet of floor area or greater or other similar rooms shall count as a Bedroom, but living rooms and foyers shall not. For all other Dwelling Units, a room or space used or intended to be used for sleeping. A Dwelling Unit where this space is also used as the primary living space shall still be counted as one bedroom.
The definition for bedroom should use the terminology of the International Residential Code, Scope where it addresses buildings that are not considered " multi-family".
Bedroom – AFor one- and two-family Dwellings and Townhouses or buildings with one or two units, a room or space 70 square feet of floor area or greater, with egress window and closet, used or intended to be used for sleeping. A "den," "library," "home office" with a closet, egress window, and 70 square feet of floor area or greater or other similar rooms shall count as a Bedroom, but living rooms and foyers shall not. For all other Dwelling Units, a room or space used or intended to be used for sleeping. A Dwelling Unit where this space is also used as the primary living space shall still be counted as one bedroom.
Comment #3Page Number: 23Paragraph / Figure / Table / Note: Table 4.2.2(1)Comment Intent: ObjectionComment Type: GeneralComment: This draft of 301 includes instructions (via RESNET 380) to use a compartmentalization measurement (with a reduction factor which is the ratio of exterior shell area to total shell area) for the air exchange rate in the minimum Rated features. In other words, guarded test results are NOT allowed in this draft of 301. I object to the exclusion of guarded test results for the air exchange Rate used in a HERS Rating. There are many companies and I believe even entire regions like the northeast where this has been common practice for many years with well established norms for how it is conducted. I have raised this with many other comapnies operating in MA almost everyone that I have spoken to feels that Guarded testing is ian important part of our current practice and we will have a lot of trouble if it is removed. The only Rater who didn't have an opinion was someone who doesn't Rate multi-family homes. This exclusion seems like an attempt to encourage compartmentalization best practices instead of just providing the best metric of a home's projected energy use with the practices now commonly availble. The guarded test is definitely a better measurement of exterior air leakage and I believe it shoudl still be allowed. The procedure for compartmetnalization testing should be an acceptable alternative to guarded testing. The difficulty of doing QA of guarded test at a later date has been raised as an objection, but it a difficulty that we have handled for many years. we have either redone guarded testing or had the QAD present for the initial testing. The other objection would be that RESNET 380 doesn't currently describe a guarded test procedure to reference. I beieve the new draft of the RESNET 380 should better address this oversight and in the meantime another standard can be referenced for multi-zone testing. I have raised this issue previously in comments on RESNET 380 and will continue to pursue this in comment periods for RESNET 380. In the meantime, we can use the language from the latest draft of RESNET 380 that went out for public comment which points to the ACCA Multi-zone test as an acceptable multizone test procedure. That standard can accomodate guraded testing. Proposed Change: In accordance with Standard ANSI/RESNET/ICC 380 Standard Method for Building Enclosure Airtightness Compliance Testing, or conduct the test in accordance with the: Air Barrier Association of America for Multi Zone Blower Test, obtain airtightness test results for: ? Building enclosure (for Detached Dwelling Units) ? Compartmentalization Boundary (for Attached Dwelling Units).
This draft of 301 includes instructions (via RESNET 380) to use a compartmentalization measurement (with a reduction factor which is the ratio of exterior shell area to total shell area) for the air exchange rate in the minimum Rated features. In other words, guarded test results are NOT allowed in this draft of 301.
I object to the exclusion of guarded test results for the air exchange Rate used in a HERS Rating. There are many companies and I believe even entire regions like the northeast where this has been common practice for many years with well established norms for how it is conducted. I have raised this with many other comapnies operating in MA almost everyone that I have spoken to feels that Guarded testing is ian important part of our current practice and we will have a lot of trouble if it is removed. The only Rater who didn't have an opinion was someone who doesn't Rate multi-family homes.
This exclusion seems like an attempt to encourage compartmentalization best practices instead of just providing the best metric of a home's projected energy use with the practices now commonly availble. The guarded test is definitely a better measurement of exterior air leakage and I believe it shoudl still be allowed. The procedure for compartmetnalization testing should be an acceptable alternative to guarded testing.
The difficulty of doing QA of guarded test at a later date has been raised as an objection, but it a difficulty that we have handled for many years. we have either redone guarded testing or had the QAD present for the initial testing.
The other objection would be that RESNET 380 doesn't currently describe a guarded test procedure to reference. I beieve the new draft of the RESNET 380 should better address this oversight and in the meantime another standard can be referenced for multi-zone testing. I have raised this issue previously in comments on RESNET 380 and will continue to pursue this in comment periods for RESNET 380.
In the meantime, we can use the language from the latest draft of RESNET 380 that went out for public comment which points to the ACCA Multi-zone test as an acceptable multizone test procedure. That standard can accomodate guraded testing.
Comment #4Page Number: 26Paragraph / Figure / Table / Note: Table 4.2.2(1)/Thermal distribution systems/Rated Home ColumnComment Intent: Not an ObjectionComment Type: TechnicalComment: This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units. This standard prohibits duct leakage to outside results from being used as an entry for a HERS Rating in an Attached Dwelling Unit. Leakage-to-outside test results are currently allowed and detailed by the RESNET adopted Multi-family Guidelines. Using the leakage-to-outside method most accurately measures systems when a portion of the system is not inside the infiltration volume. Not allowing these results to be used will result in an arbitrary decrease in projected performance, particularly for small multi-family units when Total leakage must be used. In some cases, the total duct leakage test will overestimate the energy penalty of duct leakage by an acceptable amount (for very low leakage systems or for systems that are mostly or entirely outside). In these cases, it is reasonable to accept the penalty. In other cases, eliminating the arbitrary energy penalty is worth the extra effort to conduct the duct leakage to outside test. Our recommendation edit retains the option to conduct a duct leakage test to outside in Attached Dwelling Units. Proposed Change: For forced air distribution systems: Attached Dwelling Units requiring testing(v) shall test total duct leakage or duct leakage to outside;
This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units.
This standard prohibits duct leakage to outside results from being used as an entry for a HERS Rating in an Attached Dwelling Unit. Leakage-to-outside test results are currently allowed and detailed by the RESNET adopted Multi-family Guidelines. Using the leakage-to-outside method most accurately measures systems when a portion of the system is not inside the infiltration volume. Not allowing these results to be used will result in an arbitrary decrease in projected performance, particularly for small multi-family units when Total leakage must be used. In some cases, the total duct leakage test will overestimate the energy penalty of duct leakage by an acceptable amount (for very low leakage systems or for systems that are mostly or entirely outside). In these cases, it is reasonable to accept the penalty. In other cases, eliminating the arbitrary energy penalty is worth the extra effort to conduct the duct leakage to outside test. Our recommendation edit retains the option to conduct a duct leakage test to outside in Attached Dwelling Units.
For forced air distribution systems:
Comment #5Page Number: 26-27Paragraph / Figure / Table / Note: Table 4.2.2(1)/Thermal distribution systems/Rated Home ColumnComment Intent: Not an ObjectionComment Type: TechnicalComment: This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units. By definition, because Conditioned Space Volume is a subset of Infiltration Volume, any ductwork located within the Conditioned Space Volume is also located within the Infiltration Volume. The higher DSE would always be a valid choice, so let’s eliminate the less preferred choice. In addition, the argument to advantageously rate the thermal performance of duct systems that may be in less than fully conditioned sealed attics, crawl spaces and basements appears arbitrary and counter-intuitive. Proposed Change: For untested distribution systems in Attached Dwelling Units: Located entirely within Conditioned Space Volume: DSE=0.88 Located entirely within the Infiltration Volume of the Rated Home: DSE=0.92.
By definition, because Conditioned Space Volume is a subset of Infiltration Volume, any ductwork located within the Conditioned Space Volume is also located within the Infiltration Volume. The higher DSE would always be a valid choice, so let’s eliminate the less preferred choice. In addition, the argument to advantageously rate the thermal performance of duct systems that may be in less than fully conditioned sealed attics, crawl spaces and basements appears arbitrary and counter-intuitive.
For untested distribution systems in Attached Dwelling Units:
Comment #6Page Number: 26-27Paragraph / Figure / Table / Note: Table 4.2.2(1)/Thermal distribution systems/Rated Home ColumnComment Intent: ObjectionComment Type: TechnicalComment: This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units. Ducts that qualify for a duct test exemption do so by being located entirely within conditioned space volume or within infiltration volume. Consistent with current standards, which assign no penalty for untested duct systems in Attached Dwelling Units, we object to a reduction in system efficiency and recommend use of a DSE of 1.00. Proposed Change: For untested distribution systems in Attached Dwelling Units: Located entirely within Conditioned Space Volume: DSE=0.881.0 Located entirely within the Infiltration Volume of the Rated Home: DSE=0.921.0.
Ducts that qualify for a duct test exemption do so by being located entirely within conditioned space volume or within infiltration volume. Consistent with current standards, which assign no penalty for untested duct systems in Attached Dwelling Units, we object to a reduction in system efficiency and recommend use of a DSE of 1.00.
Comment #7Page Number: 23Paragraph / Figure / Table / Note: Table 4.2.2(1)/Air exhange rate/Rated Home ColumnComment Intent: ObjectionComment Type: TechnicalComment: This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units. The Rated home Air Exchange Rate for attached dwelling units allows the use of a reduction factor to reduce the measured compartmentalization, but only for extremely tight dwelling units. This creates a discontinuity in the standard, giving credit for dwelling units that meet the threshold and drastically over-penalizing dwelling units that do not meet the threshold by counting the total leakage as leakage to/from unconditioned space. In addition, because leakage through adiabatic boundaries is often more challenging to seal and therefore often greater in total than leakage through exterior boundaries, logic behind the threshold (it is harder to predict where air is coming from/going to when the envelope is leakier, so we will not consider air to be coming from inside conditioned space unless the threshold is met) is counter-intuitive. Although we object to any threshold, we find that the proposed threshold is overly stringent, largely unachievable in the short term, arbitrary and not based on any technical research that has been shared with the RESNET membership. However, if total elimination of a threshold (reflected in our proposed change below) is not possible, we recommend that the threshold be set at 0.30 cfm50 per ft2 of Compartmentalization Boundary. This level is more achievable and has gained some level of consensus in the industry. It has been adopted by the ENEGY STAR Multifamily High-Rise Program and LEED for Homes Midrise. Proposed Change: For Attached Dwelling Units with airtightness test results <0.125 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modified by reduction factor Aext(r).
The Rated home Air Exchange Rate for attached dwelling units allows the use of a reduction factor to reduce the measured compartmentalization, but only for extremely tight dwelling units. This creates a discontinuity in the standard, giving credit for dwelling units that meet the threshold and drastically over-penalizing dwelling units that do not meet the threshold by counting the total leakage as leakage to/from unconditioned space. In addition, because leakage through adiabatic boundaries is often more challenging to seal and therefore often greater in total than leakage through exterior boundaries, logic behind the threshold (it is harder to predict where air is coming from/going to when the envelope is leakier, so we will not consider air to be coming from inside conditioned space unless the threshold is met) is counter-intuitive.
Although we object to any threshold, we find that the proposed threshold is overly stringent, largely unachievable in the short term, arbitrary and not based on any technical research that has been shared with the RESNET membership. However, if total elimination of a threshold (reflected in our proposed change below) is not possible, we recommend that the threshold be set at 0.30 cfm50 per ft2 of Compartmentalization Boundary. This level is more achievable and has gained some level of consensus in the industry. It has been adopted by the ENEGY STAR Multifamily High-Rise Program and LEED for Homes Midrise.
For Attached Dwelling Units with airtightness test results <0.125 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modified by reduction factor Aext(r).
Comment #8Page Number: 23Paragraph / Figure / Table / Note: Table 4.2.2(1)/Air exhange rate/Rated Home ColumnComment Intent: ObjectionComment Type: TechnicalComment: This comment is being issued on behalf of the Standards and Energy Code Committees of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from New Jersey to Maine. Due to the nature of the new construction, gut rehab and adaptive reuse market in the northeastern US, the members of NEHERS have considerable experience in multi-family buildings and energy ratings for attached dwelling units. The elimination of guarded blower door testing has removed the most accurate method for estimating the air leakage from outside in Attached Dwelling Units. Without this testing technique, it is unlikely that we will further our ability to answer the question “Where does the air come from?”. Although we agree that the methodology is challenging, we strongly recommend that this option be included, and the results be applied without reduction factor. Proposed Change: Compartmentalization Boundary using guarded or unguarded testing (for Attached Dwelling Units) For Attached Dwelling Units using unguarded testing with airtightness test results <0.125 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modified by reduction factor Aext(r).
The elimination of guarded blower door testing has removed the most accurate method for estimating the air leakage from outside in Attached Dwelling Units. Without this testing technique, it is unlikely that we will further our ability to answer the question “Where does the air come from?”. Although we agree that the methodology is challenging, we strongly recommend that this option be included, and the results be applied without reduction factor.
For Attached Dwelling Units using unguarded testing with airtightness test results <0.125 cfm50 per ft2 of Compartmentalization Boundary, the test results shall be modified by reduction factor Aext(r).
Comment #9Page Number: 40-41Paragraph / Figure / Table / Note: 4.2.2.5.2Comment Intent: ObjectionComment Type: TechnicalComment: For a Rated Home without one of the listed appliances, neither the Reference Home nor the Rated home should model them. If they are included in the model, the miscellaneous loads for that Dwelling Unit are effectively increased when compared with as-built conditions. These scenarios occur most frequently in Attached Dwelling Units and Sleeping Units, which are integrated more fully into this new version of the Standard, so it's important that this concept be addressed now. Since the 2006 IECC is silent on these specific items, RESNET can make the determination. Proposed Change: For a Rated Home without a refrigerator, dishwasher, range/oven, clothes washer, or clothes dryer, the values from Table 4.2.2.5(1) shall be assumed to be 0 kWh/y for both the Energy Rating Reference Home and Rated Home.
For a Rated Home without one of the listed appliances, neither the Reference Home nor the Rated home should model them. If they are included in the model, the miscellaneous loads for that Dwelling Unit are effectively increased when compared with as-built conditions. These scenarios occur most frequently in Attached Dwelling Units and Sleeping Units, which are integrated more fully into this new version of the Standard, so it's important that this concept be addressed now. Since the 2006 IECC is silent on these specific items, RESNET can make the determination.
Comment #10Page Number: 54Paragraph / Figure / Table / Note: 4.2.2.5.2.12Comment Intent: ObjectionComment Type: TechnicalComment: Heat pump water heaters add heat to a space due to losses at the tank and surrounding piping, but they also remove heat from a space due to their heat pump condenser. In addition to modeling Internal Gains, the heat sink effect of heat pump water heaters should be modeled so that the real impact of locating a heat pump water heater in the Conditioned Space Volume is accounted for. The entire effect of heat pump water heaters should be modeled. Additionally, split-system heat pump water heaters should not be penalized for removing heat from the Conditioned Space Volume. Split-system heat pump water heaters are available on the market and may become more common before this Standard is due for another revision. Proposed Change: Hot Water Tank. Where hot water tanks are located in Conditioned Space Volume, total Internal Gains in the Rated Home shall be modified to account for heat gain from the tank to the Conditioned Space Volume. Additionally, where a heat pump water heater is located in Conditioned Space Volume and is not a split system heat pump water heater, total Internal Gains and losses in the Rated Home shall be modified to account for heat transfer from the Conditioned Space Volume to the water heater via the heat pump. Internal Gains shall not be modified for hot water tanks located in Unconditioned Space Volume, Unrated Heated Space, Unrated Conditioned Space, or outdoor environment.
Heat pump water heaters add heat to a space due to losses at the tank and surrounding piping, but they also remove heat from a space due to their heat pump condenser. In addition to modeling Internal Gains, the heat sink effect of heat pump water heaters should be modeled so that the real impact of locating a heat pump water heater in the Conditioned Space Volume is accounted for. The entire effect of heat pump water heaters should be modeled.
Additionally, split-system heat pump water heaters should not be penalized for removing heat from the Conditioned Space Volume. Split-system heat pump water heaters are available on the market and may become more common before this Standard is due for another revision.
Comment #11Page Number: 55Paragraph / Figure / Table / Note: 4.2.2.6Comment Intent: ObjectionComment Type: TechnicalComment: On-Site Power Production should only be applied to the Dwelling Units that directly benefit from a reduction in purchased fossil fuels. In multifamily projects, On-Site Power Production is often installed for the benefit of the common spaces and is tied to the house meter. The language in this section rewards this self-serving behavior by allowing developers to take credit for improving the efficency of each apartment even though it doesn't have any affect on the individual Dwelling Units. This section has the opportunity to encourage developers to allocate their OPP to their tenants but does not currently do so. When the OPP does not serve the Rated Home, it should be completely ignored in the Rating. There are many other aspects of multifamily projects that are handled inconsistently (e.g., common laundry is divvied up and included, whereas parking garage lighting is not), but none of the others negatively impact tenants. Some single family homes have agreements with solar installers that effectively provides the installer with a rental contract for the homeowner's roof; the installer pays rent and sells the electricity. In this situation, the Rated Home should not be permitted to benefit from On-Site Power Production because another entity elsewhere is also benefiting; it's double-counting. Proposed Change: On-Site Power Production. The Energy Rating Reference Home shall not include On-Site Power Production. Where the Dwelling Unit project site includes On-Site Power Production (OPP), the total OPP shall be computed as the electric energy produced for the Dwelling Uniton the project site minus the equivalent electric energy use (kWheq) calculated in accordance with Equation 4.1-3 of any purchased fossil fuels used to produce the total OPP. If the OPP is a microgrid or a shared system, then tThe total OPP shall be pro-rated to the individual Dwelling Units that are directly served by that system based on the number of Bedrooms, where the per-Bedroom OPP is used to determine the Dwelling Unit OPP that is used in the determination of PEfrac.
On-Site Power Production should only be applied to the Dwelling Units that directly benefit from a reduction in purchased fossil fuels.
In multifamily projects, On-Site Power Production is often installed for the benefit of the common spaces and is tied to the house meter. The language in this section rewards this self-serving behavior by allowing developers to take credit for improving the efficency of each apartment even though it doesn't have any affect on the individual Dwelling Units. This section has the opportunity to encourage developers to allocate their OPP to their tenants but does not currently do so. When the OPP does not serve the Rated Home, it should be completely ignored in the Rating. There are many other aspects of multifamily projects that are handled inconsistently (e.g., common laundry is divvied up and included, whereas parking garage lighting is not), but none of the others negatively impact tenants.
Some single family homes have agreements with solar installers that effectively provides the installer with a rental contract for the homeowner's roof; the installer pays rent and sells the electricity. In this situation, the Rated Home should not be permitted to benefit from On-Site Power Production because another entity elsewhere is also benefiting; it's double-counting.
Comment #12Page Number: 68Paragraph / Figure / Table / Note: 23Comment Intent: ObjectionComment Type: EditorialComment: Although not open for public comment, the number of ceiling fans needs to be added to this list of Minimum Rated Features in order to perform the equation in 4.2.2.5.2.13 correctly. Proposed Change: Total number of ceiling fans in the Dwelling Unit, lLabeled cfm, Watts, and cfm/Watt at medium fan speed from EPA ENERGY STAR ceiling fan label.
Although not open for public comment, the number of ceiling fans needs to be added to this list of Minimum Rated Features in order to perform the equation in 4.2.2.5.2.13 correctly.
Comment #13Page Number: 52Paragraph / Figure / Table / Note: 4.2.2.5.2.11.2Comment Intent: ObjectionComment Type: TechnicalComment: When required, as an alternate to installing hot water recirculation systems in the commercial provisions of the IECC, heat trace can be installed. Heat trace is mentioned in the 2006 IECC and is used regularly in jurisdictions that have adopted more recent codes. Although not typically installed in single family homes, heat trace is relatively common in multifamily projects. Hot water recirculation systems can be very energy efficient, but heat trace is simply resistance heating. The energy penalty of heat trace should be included in the Rated Home only in order to more accurately represent the as-built Dwelling Unit and in order to encourage the use of more efficient systems. Proposed Change: If the Rated Home includes a hot water recirculation system, either within the Dwelling Unit or in the form of a shared recirculation system serving multiple Dwelling Units, then the annual electric consumption of the recirculation pump shall be added to the total hot water energy consumption. The recirculation pump kWh/y shall be calculated using Equation 4.2-15a for recirculation systems located completely within the Dwelling Unit. The shared recirculation pump kWh/y shall be calculated using Equation 4.2-15b for shared recirculation systems serving multiple Dwelling Units. If the Rated Home includes heat trace either within the Dwelling Unit or in the form of a shared domestic hot water system, then the annual electric consumption of the heat trace shall be added to the total hot water energy consumption.
When required, as an alternate to installing hot water recirculation systems in the commercial provisions of the IECC, heat trace can be installed. Heat trace is mentioned in the 2006 IECC and is used regularly in jurisdictions that have adopted more recent codes. Although not typically installed in single family homes, heat trace is relatively common in multifamily projects. Hot water recirculation systems can be very energy efficient, but heat trace is simply resistance heating. The energy penalty of heat trace should be included in the Rated Home only in order to more accurately represent the as-built Dwelling Unit and in order to encourage the use of more efficient systems.
Comment #14Page Number: 52Paragraph / Figure / Table / Note: 4.2.2.5.2.11.2Comment Intent: ObjectionComment Type: TechnicalComment: Alternate 2, same rationale, more specific proposed language. When required, as an alternate to installing hot water recirculation systems in the commercial provisions of the IECC, heat trace can be installed. Heat trace is mentioned in the 2006 IECC and is used regularly in jurisdictions that have adopted more recent codes. Although not typically installed in single family homes, heat trace is relatively common in multifamily projects. Hot water recirculation systems can be very energy efficient, but heat trace is simply resistance heating. The energy penalty of heat trace should be included in the Rated Home only in order to more accurately represent the as-built Dwelling Unit and in order to encourage the use of more efficient systems. Proposed Change: If the Rated Home includes a hot water recirculation system, either within the Dwelling Unit or in the form of a shared recirculation system serving multiple Dwelling Units, then the annual electric consumption of the recirculation pump shall be added to the total hot water energy consumption. The recirculation pump kWh/y shall be calculated using Equation 4.2-15a for recirculation systems located completely within the Dwelling Unit. The shared recirculation pump kWh/y shall be calculated using Equation 4.2-15b for shared recirculation systems serving multiple Dwelling Units. If the Rated Home includes heat trace either within the Dwelling Unit or in the form of a shared domestic hot water system, then the annual electric consumption of the heat trace shall be added to the total hot water energy consumption in proportion to the number of Dwelling Units served by that system.
Alternate 2, same rationale, more specific proposed language.
Comment #15Page Number: 52Paragraph / Figure / Table / Note: 4.2.2.5.2.11.2Comment Intent: ObjectionComment Type: TechnicalComment: Alternate 3, same rationale, limited to that which is installed within a Dwelling Unit. When required, as an alternate to installing hot water recirculation systems in the commercial provisions of the IECC, heat trace can be installed. Heat trace is mentioned in the 2006 IECC and is used regularly in jurisdictions that have adopted more recent codes. Although not typically installed in single family homes, heat trace is relatively common in multifamily projects. Hot water recirculation systems can be very energy efficient, but heat trace is simply resistance heating. The energy penalty of heat trace should be included in the Rated Home only in order to more accurately represent the as-built Dwelling Unit and in order to encourage the use of more efficient systems. Proposed Change: If the Rated Home includes a hot water recirculation system, either within the Dwelling Unit or in the form of a shared recirculation system serving multiple Dwelling Units, then the annual electric consumption of the recirculation pump shall be added to the total hot water energy consumption. The recirculation pump kWh/y shall be calculated using Equation 4.2-15a for recirculation systems located completely within the Dwelling Unit. The shared recirculation pump kWh/y shall be calculated using Equation 4.2-15b for shared recirculation systems serving multiple Dwelling Units. If the Rated Home includes heat trace within the Dwelling Unit, then the annual electric consumption of the heat trace shall be added to the total hot water energy consumption.
Alternate 3, same rationale, limited to that which is installed within a Dwelling Unit.
Comment #16Page Number: 67Paragraph / Figure / Table / Note: Table 4.5.2(1), Building Element 14Comment Intent: ObjectionComment Type: TechnicalComment: If heat trace is added to 4.2.2.5.2.11.2 Hot Water System Energy Consumption, then it needs to be added to the table of Minimum Rated Features. Proposed Change: Distribution Related: Distribution System Type (Standard, recirculation), Recirculation System controls [none, timer, temperature, demand (manual) or demand (sensor)], pipe insulation value, pipe length for standard distribution and heat trace, branch length for recirculation, supply + return loop length for recirculation, recirculation pump power (Watts, HP), heat trace annual energy consumption (kWh/y).
If heat trace is added to 4.2.2.5.2.11.2 Hot Water System Energy Consumption, then it needs to be added to the table of Minimum Rated Features.
Comment #17Page Number: 46Paragraph / Figure / Table / Note: 4.2.2.5.2.8Comment Intent: ObjectionComment Type: TechnicalComment: Remove the effective requirement to locate and count all clothes dryers in a multifamily project when determining the clothes dryer inputs for the Rated Home. Proposed Change: When a Dwelling Unit has no in-unit clothes dryer, and no shared clothes dryers are available in the building or on the project site for daily use by the Rated Home occupants or they exist, but the ratio of Dwelling Units to shared clothes dryers is greater than 8, the clothes dryer values from Table 4.2.2.5(1) shall be assumed for both the Energy Rating Reference Home and Rated Home.
Remove the effective requirement to locate and count all clothes dryers in a multifamily project when determining the clothes dryer inputs for the Rated Home.
Comment #18Page Number: 48Paragraph / Figure / Table / Note: 4.2.2.5.2.10Comment Intent: ObjectionComment Type: TechnicalComment: Remove the effective requirement to locate and count all clothes washers in a multifamily project when determining the clothes dryer inputs for the Rated Home. Proposed Change: When a Dwelling Unit has no in-unit clothes washer, and no shared clothes washers are available in the building or on the project site for daily use by the Rated Home occupants or they exist, but the ratio of Dwelling Units to shared clothes washers is greater than 8, the energy and hot water use of the Rated Home clothes washer shall be the same as the Energy Rating Reference Home, in accordance with Section 4.2.2.5.1.
Remove the effective requirement to locate and count all clothes washers in a multifamily project when determining the clothes dryer inputs for the Rated Home.
When a Dwelling Unit has no in-unit clothes washer, and no shared clothes washers are available in the building or on the project site for daily use by the Rated Home occupants or they exist, but the ratio of Dwelling Units to shared clothes washers is greater than 8, the energy and hot water use of the Rated Home clothes washer shall be the same as the Energy Rating Reference Home, in accordance with Section 4.2.2.5.1.
Comment #19Page Number: 54Paragraph / Figure / Table / Note: 4.2.2.5.2.13Comment Intent: ObjectionComment Type: GeneralComment: If ceiling fans, which are occupant-controlled and aren't included in the 2006 IECC Reference Home, are included in the Reference Home and in the Rated Home, why aren't range hood fans or bath fans included? Some bath fans even have humidistats, which keep indoor humidity levels within acceptable ranges automatically. Arguably bath fans and range hood fans are used more often than ceiling fans and have a real impact on the Rated Home all year. They remove excess heat in the summer (while also drawing in excess humidity in many climates) and they remove heated air in the winter (while also drawing in unheated air). None of these fans are described in the 2006 IECC Reference Home as far as I could tell. Proposed Change: No proposed change at this time.
If ceiling fans, which are occupant-controlled and aren't included in the 2006 IECC Reference Home, are included in the Reference Home and in the Rated Home, why aren't range hood fans or bath fans included? Some bath fans even have humidistats, which keep indoor humidity levels within acceptable ranges automatically. Arguably bath fans and range hood fans are used more often than ceiling fans and have a real impact on the Rated Home all year. They remove excess heat in the summer (while also drawing in excess humidity in many climates) and they remove heated air in the winter (while also drawing in unheated air). None of these fans are described in the 2006 IECC Reference Home as far as I could tell.
No proposed change at this time.
Comment #20Page Number: A-1Paragraph / Figure / Table / Note: Normative Appendix AComment Intent: ObjectionComment Type: GeneralComment: In order to offer any review of Normative Appendix A the draft needs to be provided. The time period for comments should start when the draft is provided for review. The time period for comment on the overall document should restart when the draft Appendix A is put out for comment. Proposed Change: Post the draft of Appendix A, apparently also called Addendum F.
In order to offer any review of Normative Appendix A the draft needs to be provided. The time period for comments should start when the draft is provided for review. The time period for comment on the overall document should restart when the draft Appendix A is put out for comment.
Post the draft of Appendix A, apparently also called Addendum F.
Comment #21Page Number: B-1Paragraph / Figure / Table / Note: Normative Appendix BComment Intent: ObjectionComment Type: GeneralComment: In order to offer any review of Normative Appendix B the draft needs to be provided. The time period for comments should start when the draft is provided for review. The time period for comment on the overall document should restart when the draft Appendix A is put out for comment. Proposed Change: Provide a draft of Appendix B, also know as Addendum N, for review. Restart the time period for comment on the new standard.
In order to offer any review of Normative Appendix B the draft needs to be provided. The time period for comments should start when the draft is provided for review. The time period for comment on the overall document should restart when the draft Appendix A is put out for comment.
Provide a draft of Appendix B, also know as Addendum N, for review. Restart the time period for comment on the new standard.
Comment #22Page Number: 2, 84, 86, 90Paragraph / Figure / Table / Note: Notes 1, 66, 67, Normative ReferencesComment Intent: ObjectionComment Type: GeneralComment: Remove references to the RESNET Mortgage Industry National Home Energy Rating Standards, even if these are labeled as "informative notes". The notes say a portion of the RESNET Mortgage Industry National Home Energy Rating Standards is "required" and are therefor consfusing. The Normative References should include only those documents that are really normative. This appears to be a way of requiring a non-ANSI part of RESNET's standards in an ANSI document without the required ANSI review process. Proposed Change: Remove notes 1, 66 and 67. Remove "RESNET Mortgage Industry National Home Energy Rating Standards" from the Normative References section.
Remove references to the RESNET Mortgage Industry National Home Energy Rating Standards, even if these are labeled as "informative notes". The notes say a portion of the RESNET Mortgage Industry National Home Energy Rating Standards is "required" and are therefor consfusing. The Normative References should include only those documents that are really normative.
This appears to be a way of requiring a non-ANSI part of RESNET's standards in an ANSI document without the required ANSI review process.
Remove notes 1, 66 and 67. Remove "RESNET Mortgage Industry National Home Energy Rating Standards" from the Normative References section.