The following comments have been submitted:
Comment #1Page Number: 50Paragraph / Figure / Table / Note: C3Comment Intent: ObjectionComment Type: TechnicalComment: Effective duct insulation R-Values from Palmiter, et al, are not intended to be applied to ducts in buried insulation. Table C.3(1) should only apply to ducts with wrapped insulation and separate guidance should be given for ducts in buried insulation.
Effective duct insulation R-Values from Palmiter, et al, are not intended to be applied to ducts in buried insulation. Table C.3(1) should only apply to ducts with wrapped insulation and separate guidance should be given for ducts in buried insulation.
Comment #2Page Number: 2Paragraph / Figure / Table / Note: 4.1.1Comment Intent: ObjectionComment Type: TechnicalComment: The newly-defined Battery Storage Losses need clarification to ensure consistent calculation across software tools. At a minimum, the Battery Storage Loss concept should be specified as a total annual energy value, and tied to the new Minimum Rated Feature of "round-trip efficiency" for On-Site Battery Storage. Proposed Change: 4.1.1 Calculating the Energy Rating Index. The Energy Rating Index shall be determined in accordance with Equation 4.1-2. Energy Rating Index = PEfrac * [TnML / (TRL* IAFRH)] * 100 (Equation 4.1-2) where: TnML = nMEULHEAT + nMEULCOOL + nMEULHW + ECLA + ECVENT + ECDH (MBtu/y). TRL = REULHEAT + REULCOOL + REULHW + RECLA + RECVENT + RECDH (MBtu/y). IAFRH = Index Adjustment Factor of Rated Home in accordance with Equation 4.3-2. and where: ECLA = The Rated Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.2, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate. RECLA = The Reference Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.1, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate. ECVENT = The Rated Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293. RECVENT = The Reference Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293. ECDH = The Rated Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293. RECDH = The Reference Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293. and where: PEfrac = (TEU – OPP + BSL) / TEU TEU = Total energy use of the Rated Home including all rated and nonrated energy features where all fossil fuel site energy uses (Btufossil) are converted to equivalent electric energy use (kWheq) in accordance with Equation 4.1-3. OPP = On-Site Power Production as defined by Section 4.2.2.7 of this Standard. BSL = Battery Storage Losses, calculated as total annual energy based on the round-trip efficiency for the On-Site Battery Storage
The newly-defined Battery Storage Losses need clarification to ensure consistent calculation across software tools. At a minimum, the Battery Storage Loss concept should be specified as a total annual energy value, and tied to the new Minimum Rated Feature of "round-trip efficiency" for On-Site Battery Storage.
4.1.1 Calculating the Energy Rating Index. The Energy Rating Index shall be determined in accordance with Equation 4.1-2.
Energy Rating Index = PEfrac * [TnML / (TRL* IAFRH)] * 100 (Equation 4.1-2)
where:
TnML = nMEULHEAT + nMEULCOOL + nMEULHW + ECLA + ECVENT + ECDH (MBtu/y).
TRL = REULHEAT + REULCOOL + REULHW + RECLA + RECVENT + RECDH (MBtu/y).
IAFRH = Index Adjustment Factor of Rated Home in accordance with Equation 4.3-2.
and where:
ECLA = The Rated Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.2, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate.
RECLA = The Reference Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.1, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate.
ECVENT = The Rated Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293.
RECVENT = The Reference Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293.
ECDH = The Rated Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293.
RECDH = The Reference Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293.
PEfrac = (TEU – OPP + BSL) / TEU
TEU = Total energy use of the Rated Home including all rated and nonrated energy features where all fossil fuel site energy uses (Btufossil) are converted to equivalent electric energy use (kWheq) in accordance with Equation 4.1-3.
OPP = On-Site Power Production as defined by Section 4.2.2.7 of this Standard.
BSL = Battery Storage Losses, calculated as total annual energy based on the round-trip efficiency for the On-Site Battery Storage
Comment #3Page Number: 4Paragraph / Figure / Table / Note: 4.1.2Comment Intent: ObjectionComment Type: TechnicalComment: This corrects my preceding entry, which accidentally referenced section 4.1.1 instead of 4.1.2 For consistency across software tools, clarification is needed on how Battery Storage Losses are calculated. At a minimum, we should specify this value is in terms of total annual energy, and based on the round-trip efficiency that is now a Minimum Rated Feature for On-Site Battery Storage systems. Proposed Change: 4.1.2 Calculating the Energy Rating Index. The Energy Rating Index shall be determined in accordance with Equation 4.1-2. Energy Rating Index = PEfrac * [TnML / (TRL* IAFRH)] * 100 (Equation 4.1-2) where: TnML = nMEULHEAT + nMEULCOOL + nMEULHW + ECLA + ECVENT + ECDH (MBtu/y). TRL = REULHEAT + REULCOOL + REULHW + RECLA + RECVENT + RECDH (MBtu/y). IAFRH = Index Adjustment Factor of Rated Home in accordance with Equation 4.3-2. and where: ECLA = The Rated Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.2, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate. RECLA = The Reference Home energy consumption for lighting, appliances and MELs as defined by Section 4.2.2.5.1, converted to MBtu/y, where MBtu/y = (kWh/y)/293 or (Therms/y)/10, as appropriate. ECVENT = The Rated Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293. RECVENT = The Reference Home energy consumption for Dwelling Unit Mechanical Ventilation System fans, converted to MBtu/y, where MBtu/y = (kWh/y)/293. ECDH = The Rated Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293. RECDH = The Reference Home energy consumption for dehumidification, converted to MBtu/y, where MBtu/y = (kWh/y)/293. and where: PEfrac = (TEU – OPP + BSL) / TEU TEU = Total energy use of the Rated Home including all rated and nonrated energy features where all fossil fuel site energy uses (Btufossil) are converted to equivalent electric energy use (kWheq) in accordance with Equation 4.1-3. OPP = On-Site Power Production as defined by Section 4.2.2.7 of this Standard. BSL = Battery Storage Losses, calculated as total annual energy based on the round-trip efficiency for the On-Site Battery Storage
This corrects my preceding entry, which accidentally referenced section 4.1.1 instead of 4.1.2
For consistency across software tools, clarification is needed on how Battery Storage Losses are calculated. At a minimum, we should specify this value is in terms of total annual energy, and based on the round-trip efficiency that is now a Minimum Rated Feature for On-Site Battery Storage systems.
4.1.2 Calculating the Energy Rating Index. The Energy Rating Index shall be determined in accordance with Equation 4.1-2.
Comment #4Page Number: 15Paragraph / Figure / Table / Note: 4.2.2.7Comment Intent: ObjectionComment Type: TechnicalComment: The top-level language of section 4.2.2.7 around Internal Gains conflicts with more detailed and nuanced language in subsection 4.2.2.7.2. Where "modified" was confusing, replacement with "simulated" provides clarity. The proposed edit to the remainder of the sentence resolves the inherent conflict with subsection 4.2.2.7.2. For instance, unconditioned basements interact with the CSV, and gains from refrigerators, clothes washers and clothes dryers within them do influence the temperature of such basements. Existing accredited software tools do currently model these gains. The proposed edit to the Informative footnote corrects the example; where a software tool collects and simulates details about an attached garage, internal gains within that garage impact the garage temperature and therefor also impact the Rated Home CSV. One of the accredited rating tools does require sufficient inputs to bound the space for attached garages. Proposed Change: 4.2.2.7. Lighting, Appliances, Miscellaneous Energy Loads (MELs), Ventilation and Service Hot Water Systems. Unless otherwise specified, hourly energy use for Lighting, Appliances, and Miscellaneous Energy Loads shall be determined according to Equation 4.2-X1. ((Annual Energy)/365)*(Hourly Profile Value)*(Monthly Multiplier) Equation 4.2-X1 where “Hourly Profile Value” and “Monthly Multiplier” are defined in Normative Appendix C.4. If no corresponding “Hourly Profile Value” or “Monthly Multiplier” is provided in Normative Appendix C.4, values of 0.042 and 1.00, respectively, shall be used. Hourly energy for refrigerators is determined according to Equation 4.2-X2[1]: ((Annual Energy)/8760)*(a + b*Tspace) Equation 4.2-X2 Where: a = Constant Coefficient from Normative Appendix C.4 Table C.4(2) b = Temperature Coefficient from Normative Appendix C.4 Table C.4(2) Tspace = Temperature of the space where the refrigerator is located Hourly Internal Gains associated with Lighting, Appliances, and Miscellaneous Energy Loads shall be determined by applying the values of finternal, fsensible associated with the end use. The total Internal Gain associated with an end use energy is determined by finternal. The Internal Gain is then split into sensible (fsensible) and latent (1 – fsensible) portions. Internal Gains shall not be modified simulated for Lighting, Appliances, and Miscellaneous Energy Loads located in Unconditioned Space Volume that is not within the Rated Home, Unrated Heated Space, Unrated Conditioned Space or outdoor environment.[2][bkc3] [1] (Informative Note) Calculated refrigerator annual energy will deviate from the annual energy input into the equation. [2] (Informative Note) Example: an unconditioneda detached garage.
The top-level language of section 4.2.2.7 around Internal Gains conflicts with more detailed and nuanced language in subsection 4.2.2.7.2.
Where "modified" was confusing, replacement with "simulated" provides clarity.
The proposed edit to the remainder of the sentence resolves the inherent conflict with subsection 4.2.2.7.2. For instance, unconditioned basements interact with the CSV, and gains from refrigerators, clothes washers and clothes dryers within them do influence the temperature of such basements. Existing accredited software tools do currently model these gains.
The proposed edit to the Informative footnote corrects the example; where a software tool collects and simulates details about an attached garage, internal gains within that garage impact the garage temperature and therefor also impact the Rated Home CSV. One of the accredited rating tools does require sufficient inputs to bound the space for attached garages.
4.2.2.7. Lighting, Appliances, Miscellaneous Energy Loads (MELs), Ventilation and Service Hot Water Systems.
Unless otherwise specified, hourly energy use for Lighting, Appliances, and Miscellaneous Energy Loads shall be determined according to Equation 4.2-X1.
((Annual Energy)/365)*(Hourly Profile Value)*(Monthly Multiplier)
Equation 4.2-X1
where “Hourly Profile Value” and “Monthly Multiplier” are defined in Normative Appendix C.4. If no corresponding “Hourly Profile Value” or “Monthly Multiplier” is provided in Normative Appendix C.4, values of 0.042 and 1.00, respectively, shall be used.
Hourly energy for refrigerators is determined according to Equation 4.2-X2[1]:
((Annual Energy)/8760)*(a + b*Tspace) Equation 4.2-X2
Where:
a = Constant Coefficient from Normative Appendix C.4 Table C.4(2)
b = Temperature Coefficient from Normative Appendix C.4 Table C.4(2)
Tspace = Temperature of the space where the refrigerator is located
Hourly Internal Gains associated with Lighting, Appliances, and Miscellaneous Energy Loads shall be determined by applying the values of finternal, fsensible associated with the end use. The total Internal Gain associated with an end use energy is determined by finternal. The Internal Gain is then split into sensible (fsensible) and latent (1 – fsensible) portions.
Internal Gains shall not be modified simulated for Lighting, Appliances, and Miscellaneous Energy Loads located in Unconditioned Space Volume that is not within the Rated Home, Unrated Heated Space, Unrated Conditioned Space or outdoor environment.[2][bkc3]
[1] (Informative Note) Calculated refrigerator annual energy will deviate from the annual energy input into the equation.
[2] (Informative Note) Example: an unconditioneda detached garage.
Comment #5Page Number: 35Paragraph / Figure / Table / Note: 4.2.2.7.2.12Comment Intent: ObjectionComment Type: EditorialComment: The wrong phrase was struck here; the LCFSW language is what should be removed, and has been removed elsewhere. The EnergyGuide language should have been retained. Proposed Change: 4.2.2.7.2.12. Ceiling Fans. Where the number of ceiling fans included in the Rated Home is equal to or greater than the number of Bedrooms plus one, they shall also be included in the Reference Home. The number of Bedrooms plus one (Nbr+1) ceiling fans shall be assumed in both the Reference Home and the Rated Home. A daily ceiling fan operating schedule equal to 10.5 full-load hours according to Normative Appendix C.4 Table C4(5). shall be assumed in both the Reference Home and the Rated Home during months with an average outdoor temperature greater than 63 ºF. The cooling thermostat (but not the heating thermostat) shall be set up by 0.5 ºF in both the Reference and Rated Home during these months. The Reference Home shall use number of Bedrooms plus one (Nbr+1) standard ceiling fans of 42.6 Watts each. The Rated Home shall use the Labeled Ceiling Fan Standardized Watts (LCFSW)ceiling fan EnergyGuide label to obtain the standardized “Energy Use” Watts and also multiplied by number of Bedrooms plus one (Nbr+1) fans to obtain total ceiling fan wattage for the Rated Home. The Rated Home LCFSW shall be calculated in accordance with Equation 4.2-46. LCFSW = (3000cfm) / (cfm/Watt as labeled at medium speed) (Equation 4.2-46) Where installed ceiling fans in the Rated Home have different EnergyGuide labelsvalues of LCFSW, the average LCFSW”Energy Use” Watts shall be used for calculating ceiling fan energy use in the Rated Home. During periods of fan operation, the fan wattage at 100-percent Internal Gain fraction shall be added to Internal Gains for both the Reference and Rated Homes (finternal = 1.0 and fsensible = 1.0). In addition, annual ceiling fan energy use, in MBtu/y [(kWh/y)/293], for both the Rated and Reference Homes shall be added to the lighting and appliance energy consumption (ECLA and RECLA, as appropriate) as specified by Equation 4.1-2 in Section 4.1.2.
The wrong phrase was struck here; the LCFSW language is what should be removed, and has been removed elsewhere. The EnergyGuide language should have been retained.
4.2.2.7.2.12. Ceiling Fans. Where the number of ceiling fans included in the Rated Home is equal to or greater than the number of Bedrooms plus one, they shall also be included in the Reference Home. The number of Bedrooms plus one (Nbr+1) ceiling fans shall be assumed in both the Reference Home and the Rated Home. A daily ceiling fan operating schedule equal to 10.5 full-load hours according to Normative Appendix C.4 Table C4(5). shall be assumed in both the Reference Home and the Rated Home during months with an average outdoor temperature greater than 63 ºF. The cooling thermostat (but not the heating thermostat) shall be set up by 0.5 ºF in both the Reference and Rated Home during these months.
The Reference Home shall use number of Bedrooms plus one (Nbr+1) standard ceiling fans of 42.6 Watts each. The Rated Home shall use the Labeled Ceiling Fan Standardized Watts (LCFSW)ceiling fan EnergyGuide label to obtain the standardized “Energy Use” Watts and also multiplied by number of Bedrooms plus one (Nbr+1) fans to obtain total ceiling fan wattage for the Rated Home. The Rated Home LCFSW shall be calculated in accordance with Equation 4.2-46.
LCFSW = (3000cfm) / (cfm/Watt as labeled at medium speed)
(Equation 4.2-46)
Where installed ceiling fans in the Rated Home have different EnergyGuide labelsvalues of LCFSW, the average LCFSW”Energy Use” Watts shall be used for calculating ceiling fan energy use in the Rated Home.
During periods of fan operation, the fan wattage at 100-percent Internal Gain fraction shall be added to Internal Gains for both the Reference and Rated Homes (finternal = 1.0 and fsensible = 1.0). In addition, annual ceiling fan energy use, in MBtu/y [(kWh/y)/293], for both the Rated and Reference Homes shall be added to the lighting and appliance energy consumption (ECLA and RECLA, as appropriate) as specified by Equation 4.1-2 in Section 4.1.2.
Comment #6Page Number: 40Paragraph / Figure / Table / Note: 7.1.3.7Comment Intent: ObjectionComment Type: EditorialComment: Where an ERI is being calculated, not only should the edition of Std 301 and its Addenda be cited, but also any additional documents used to modify that Standard and Addenda. A prominent example is RESNET MINHERS Chapter 3. Proposed Change: 7.1.3.7 The edition of the Standard used to determine the Rating, including any Addenda and other documents used to modify the Standard.[1] [1] (Informative note) For example, “Calculated in accordance with ANSI / RESNET / ICC 301-2019, including Addenda A & B”
Where an ERI is being calculated, not only should the edition of Std 301 and its Addenda be cited, but also any additional documents used to modify that Standard and Addenda. A prominent example is RESNET MINHERS Chapter 3.
7.1.3.7 The edition of the Standard used to determine the Rating, including any Addenda and other documents used to modify the Standard.[1]
[1] (Informative note) For example, “Calculated in accordance with ANSI / RESNET / ICC 301-2019, including Addenda A & B”
Comment #7Page Number: 12Paragraph / Figure / Table / Note: 4.2.2 section xComment Intent: ObjectionComment Type: TechnicalComment: When all the ductwork is verified to be located within the conditioned space boundaries of the house, the default DSE for untested systems should be HIGHER, not lower. Using .96 mirrors the 2006 IECC which is the basis for the HERS calculations. .80 would imply that duct system losses would account for 20% of the manual J load which is unreasonable for a system located entirely within conditioned space. Proposed Change: When both of the following conditions are met and documented, duct leakage testing is also not required. If duct leakage testing is not performed, a DSE of 0.80- 0.96 shall be applied to both the heating and cooling system efficiencies.
When all the ductwork is verified to be located within the conditioned space boundaries of the house, the default DSE for untested systems should be HIGHER, not lower. Using .96 mirrors the 2006 IECC which is the basis for the HERS calculations. .80 would imply that duct system losses would account for 20% of the manual J load which is unreasonable for a system located entirely within conditioned space.
When both of the following conditions are met and documented, duct leakage testing is also not required. If duct leakage testing is not performed, a DSE of 0.80- 0.96 shall be applied to both the heating and cooling system efficiencies.
Comment #8Page Number: 36Paragraph / Figure / Table / Note: 4.2.2.9.1Comment Intent: ObjectionComment Type: TechnicalComment: The original proposed language assumes that a two bedroom unit would use 2x the battery capacity as a one bedroom unit. In reality, the additional energy used is only an incremental increase because there is still only one heating system, one refrigerator, one water heater etc. Each of those systems will have additional use, but not 100% more use for each bedroom. Since solar PV capacity is divided among units based on square footage (CFA), we propose doing the same for battery capacity. Raters would take the total CFA of all the units and divide battery capacity by that area to come up with a KWH battery storage capacity per square foot to apply to each unit. Proposed Change: 4.2.2.9.1 For Dwelling Units that share On-Site Battery Storage, the battery charge/discharge rates and capacity shall be pro-rated to individual Dwelling Units based on the number of Bedrooms conditioned floor area such that the per-Bedroom Square foot On-Site Battery Storage charge/discharge rates and capacity is used in the determination of the Energy Rating Index and the CO2e Rating Index of the individual Dwelling Units that share the On-Site Battery Storage.
The original proposed language assumes that a two bedroom unit would use 2x the battery capacity as a one bedroom unit. In reality, the additional energy used is only an incremental increase because there is still only one heating system, one refrigerator, one water heater etc. Each of those systems will have additional use, but not 100% more use for each bedroom. Since solar PV capacity is divided among units based on square footage (CFA), we propose doing the same for battery capacity. Raters would take the total CFA of all the units and divide battery capacity by that area to come up with a KWH battery storage capacity per square foot to apply to each unit.
4.2.2.9.1 For Dwelling Units that share On-Site Battery Storage, the battery charge/discharge rates and capacity shall be pro-rated to individual Dwelling Units based on the number of Bedrooms conditioned floor area such that the per-Bedroom Square foot On-Site Battery Storage charge/discharge rates and capacity is used in the determination of the Energy Rating Index and the CO2e Rating Index of the individual Dwelling Units that share the On-Site Battery Storage.