Draft PDS-01, RESNET/ICC 301-2022 Addendum C-202x, Interim Updates

Proposed standard BSR/RESNET/ICC 301-2022 Addendum C-202x amends the 2022 edition of Standard 301 to provide clarifications and interim updates. The proposed revisions address the following major subjects and others: clarifications to improve the consistency of rating software calculations; definitions and acronyms for terms used in the Standard; new federal HVAC appliance SEER2 and HSPF2 ratings and ceiling fan ratings; the treatment of shared water heater losses for multi-family dwelling units; balanced mechanical ventilation; duct leakage where all ducts are within conditioned space; carbon dioxide index calculations; onsite battery storage; multiple end-use loads; interior shading; reporting of the edition of standard ANSI/RESNET/ICC 301 that rating calculations are compliant with, and; interpretations issued for ANSI/RESNET/ICC 301-2022.

RESNET released a first public review draft of proposed Addendum C in January 2023 but subsequently discontinued the initial project after a second public review. Development of the Addendum was reinitiated in August with an expanded set of interim updates to Standard 301. This draft is the first public review draft for the expanded proposed addendum. All proposed amendments in this draft are open for comment and parties must submit their comments specific to this draft for them to be considered by SDC 300. Comments on drafts from the discontinued project will not be automatically carried forward.

Draft PDS-01 of RESNET/ICC 301-2022 Addendum C-202x is submitted for public comment for 45 days, beginning December 15, 2023, and ending January 29, 2024. Only the changes shown in draft PDS-01 by strike-through and underline and red print are open for comment.

To review the draft addendum click on Draft PDS-01, RESNET/ICC 301-2022 Addendum C-202x, Interim Updates

To submit your comments, click on “SUBMIT COMMENTS HERE” below.

Comments are posted in real time and you will be able to review comments by clicking on “VIEW COMMENTS HERE” below.

The public comment period opens December 15.

Entry Date: December 19, 2023 at 5:59 PM

Full Name: Brian Christensen

Affiliation: Residential Energy Management Services

Address: 7605 Bergamo Ave Sarasota, Florida 34238

Phone Number: 19412034750

Email: brian@remsvc.com

Page Number: 23

Section/Table/Figure Number: 4.2.2.7.2

Comment Intent: Objection

Comment Type: Editorial

Comment:

The following attempts to fix what I believe was a typo, and corrects the structure of the sentence.

Proposed Change to Amendment:

4.2.2.7.2.  Energy Rating Rated Homes. 1  The lighting, appliance, hot water heating, ventilation systems and Miscellaneous Energy Loads in the Energy Rating Rated Home shall be determined in accordance with Sections 4.2.2.7.2.1 through 4.2.2.7.2.14. For a Rated Home without a refrigerator, dishwasher, range/oven, clothes washer or clothes dryer, the values from Table 4.2.2.7(1) shall be assumed for both the Energy Rating Reference Home and Rated Home. Unless specified, the values of finternal and fsensible for end uses in the Rated Home shall be the same as those listed in Tables 4.2.2.7(1) and Tables 4.2.2.7(2) according to the fuel type of the appliance in the Rated Home.

Internal Gains shall be included in the simulation of the appropriate space within the Rated Home and where a heat balance of the space is explicitly modeled by the software.

Entry Date: December 19, 2023 at 6:19 PM

Full Name: Brian Christensen

Affiliation: Residential Energy Management Services

Address: 7605 Bergamo Ave Sarasota, Florida 34238

Phone Number: 19412034750

Email: brian@remsvc.com

Page Number: 39

Section/Table/Figure Number: 4.2.2.7.2.12

Comment Intent: Objection

Comment Type: Editorial

Comment:

Correcting an editing error in the comment version, to align with the original proposed language for Ceiling Fans.

Proposed Change to Amendment:

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 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 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.

 

Where installed ceiling fans in the Rated Home have different EnergyGuide labelsvalues of LCFSW, the average ”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. 1

Entry Date: January 22, 2024 at 11:23 AM

Full Name: Scott Horowitz

Affiliation: National Renewable Energy Laboratory

Address: 15013 Denver West Parkway Golden, Colorado 80401

Phone Number: 303-384-7560

Email: scott.horowitz@nrel.gov

Page Number: 43

Section/Table/Figure Number: 4.4.3.1.4/4.4.3.2.4

Comment Intent: Objection

Comment Type: Technical

Comment:

The interior shading coefficients for the Reference/Rated Homes have been changed in Table 4.2.2(1) to be a function of SHGC. It would make sense that the values used for heat transfer calculations should also be used for HVAC sizing. There is no reason to think an occupant would operate their interior shading differently during the 1%/99% design conditions than they would during the summer/winter seasons more generally.

Proposed Change to Amendment:

4.4.3.   HVAC Sizing.

4.4.3.1.  Energy Rating Reference Home.

4.4.3.1.4.   All windows shall have blinds/draperies that are positioned in a manner that gives an Internal Shade Coefficient (ISC) of 0.85 0.92-(0.21*SHGC) This value is represented in ACCA Manual J, 8th Edition as “dark, fully drawn roller shades”.

4.4.3.2.   Rated Home.

4.4.3.2.4.   Windows shall include observed blinds/draperies.  For new homes, all windows shall assume blinds/draperies that are positioned in a manner that gives an Internal Shade Coefficient (ISC) of 0.85 0.92-(0.21*SHGC)This value is represented in ACCA Manual J, 8th Edition as “dark fully drawn roller shades”.

Entry Date: January 28, 2024 at 8:36 PM

Full Name: Jim Edelson

Affiliation: New Buildings Institute

Address: 151 SW 1st Ave. Portland, Oregon 97204

Phone Number: 503-209-4625

Email: jim@newbuildings.org

Page Number: 1

Section/Table/Figure Number: Definitions

Comment Intent: Objection

Comment Type: Technical

Comment:

Standard 301 should avoid a definition of carbon dioxide equivalent that includes a reference to a specific GWP time horizon.  Both ASHRAE 228-2023 and ASHRAE 189.1-2023 use the same paragraph in their respective definitions, and that is included in this proposal.  ASHRAE 189.1-2023 includes one additional sentence which is merely informative, but the definitional sentence in this proposal is identical in both standards.

 

Since ASHRAE Standard 90.2 references RESNET 301 on this matter, not only would the RESNET 301 proposed definition bring this standard out of alignment, it will cause confusion within those jurisdictions who adopt ASHRAE 90.2 but at the same time statutorily must accommodate a conflicting  CO2e definition. The ASHRAE Board of Directors in January, 2024 initiated an effort to reduce or eliminate conflicts  on emissions references among the Standards it publishes,

The 100-year GWP is not universally accepted and including it in the definition will render the standards more difficult to implement in the growing number of jurisdictions that require the use or consideration of 20 yr GWP.  Such is the case for the mandated use of 20 yr GWP in New Jersey, and the same was recently reconfirmed by the NY Legislature in 2023 after being mandated in the Climate Act of 2019 for all policy applications within the state.

Even though 20 year GWP is frequently characterized as a policy of the IPCC, as far back as 2013 the   IPCC authors stated that “the choice of GWP time horizon is a value, or political, judgement”.  (Chapter 8, Anthropogenic and Natural Radiative Forcing; Climate Change 2013: The Physical Science Basis: Contributions of Working Group 1 to the Fifth Assessment Report of the IPCC)

On Page 711 of the same report, the authors stated,  “There is no scientific argument for selecting 100 years compared with other choices.  The choice of time horizon is a value judgement because it depends on relative weights assigned to effects at different times.”  And on page 716 of the same document, “The weighting of effects over time – choice of time horizon in the case of GWP and GTP-is value-based.….. Finally, it is important to be aware that all metric choices, even ‘traditional’ or ‘widely used’ metrics, contain implicit value judgements as well as large uncertainties “.

ASHRAE 189.1-2023 and ASHRAE 228-2023 publish scientifically correct definitions.    We encourage RESNET 301 (and its reference by ASHRAE 90.2) to do the same by not stating a GWP time horizon in the definition of a term.

 

Proposed Change to Amendment:

Carbon Dioxide Equivalent (CO2e) EmissionsThe CO2 pre-combustion and combustion emissions and the emissions of CH4 and N2O at their 100-year GWP equivalent emissions in accordance with the IPCC Sixth Assessment Report.  a measure used to compare the impact of various greenhouse gases based on their time horizon global warming potential. CO2e approximates the time-integrated warming effect of a unit mass of a given greenhouse gas relative to that of carbon dioxide (CO2)

Entry Date: January 28, 2024 at 8:52 PM

Full Name: Jim Edelson

Affiliation: New Buildings Institute

Address: 151 SW 1st Ave. Portland, Oregon 97204

Phone Number: 5032094625

Email: jim@newbuildings.org

Page Number: 1

Section/Table/Figure Number: Definitions

Comment Intent: Objection

Comment Type: Technical

Comment:

The proposed definition does not include a reference to a rating for the round-trip efficiency value nor does it specify which form of round-trip loss is to be included in the published formula.   To correct these issues, the language in this proposal is taken from the California Energy Commission, Draft 2025 Energy Code Express Terms.

Proposed Change to Amendment:

Battery Storage Round-trip Losses – Charging and discharging energy losses calculated as total annual energy based on the round-trip rated single charge-discharge cycle AC to AC (round-trip) efficiency for the On-Site Battery Storage system

Entry Date: January 29, 2024 at 2:49 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 5

Section/Table/Figure Number: 4.1.1.1

Comment Intent: Not an Objection

Comment Type: Technical

Comment:

The proposed language includes “fossil fuel back-up heating for heat pump equipment shall be considered separate equipment in this calculation.” The question here is, what percentage of the capacity of the back-up system will be assigned?

 

4.1.1.1.                 Multiple Equipment Serving the Same End Use Load. When the Rated Home has multiple equipment serving the same end use load, the value of nMEUL for that end use shall be determined by summing the nMEULs for each individual system. For each equipment in the Rated Home, the Reference Home shall be assigned a corresponding equipment. EC_x, EEC_x, a, and b shall be determined separately for each equipment in the Rated Home. EC_r, EEC_r shall be determined for each corresponding equipment in the Reference Home. REUL for each equipment shall be determined as the Reference Home End Use Load met by the corresponding equipment in the Reference Home. Fossil fuel back-up heating for heat pump equipment shall be considered separate equipment in this calculation.

Proposed Change to Amendment:

Propose additional language to be added to describe how to calculate the percentage of load served for the back-up heating equipment.

 

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

Entry Date: January 29, 2024 at 2:50 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 9

Section/Table/Figure Number: Table 4.2.2(1) Building Component “Roofs”

Comment Intent: Objection

Comment Type: Technical

Comment:

Proposed Predominant Shape: Footnote 6 describes examples of roof shapes as “flat, sloped/shed, hip, and gable”. It is unclear if this is to imply that additional roof shapes (gable, hip, etc.) are to be added as software inputs. Traditionally, these have been modeled with simplified inputs of “vaulted”, “vented attic”, “sealed attic” to calculate the heat flow dynamics with the verifier calculating the area. A “flat” roof as described in the proposed footnote (6) could be confusing since this could be interpreted to represent a roof system ≤2/12 roof pitch or the flat ceiling area of a vented attic. It would be helpful to understand the rationale behind the proposed language changes.

Proposed Change to Amendment:

Predominant Shape:6 Same as Rated Home  

6 (Informative Note) Examples of roof shapes include Flat, Sloped/Shed, Hip and Gable.

 

Energy Rating Reference Home: Predominant Roof Type. Same as Rated Home.

Footnote 6: “(Informative Note) Examples of roof types include “Vented Attic, Vaulted, Roof Slope/Sealed”

 

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

Entry Date: January 29, 2024 at 2:52 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 42 & 49

Section/Table/Figure Number: Table 4.5.2(1): 2. Walls Assembly “orientation (for exterior) walls”

Comment Intent: Objection

Comment Type: Technical

Comment:

Proposing the inclusion of orientation for wall assemblies presents additional potential for calculation errors along with a potential increase in errors around window/wall ratios.

Proposed Change to Amendment:

Propose striking “orientation (for exterior walls),” from the amendment.

 

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

Entry Date: January 29, 2024 at 2:54 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 44

Section/Table/Figure Number: Section 4.5.2 / Footnote 29

Comment Intent: Objection

Comment Type: Technical

Comment:

The proposal to include a “temporary sales office” as a portion of the CFA and/or CSV along with potentially uninsulated wall assemblies would place an undue burden on the rater/verifier as well as an unnecessary penalty in the building model as it is highly likely that a garage (space with installed overhead doors, etc.) converted to a “temporary” sales office will be converted back to a garage at the time of sale. The space as modeled should align with the construction drawings submitted for the permit application and/or as-built drawings.

29 (Informative Note) For example, for a model home in which a garage has been converted into a sales office, the Minimum Rated Features shall reflect the home with the sales office because that is the state of the home at the time of the inspection, even if the builder intends to convert the sales office back to a garage prior to closing. Alternatively, if the inspection is completed after the sales office has been converted back to a garage, then the Minimum Rated Features shall reflect the home with the garage.”

Proposed Change to Amendment:

Propose striking the above proposed footnote 29 from this amendment.

 

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

Entry Date: January 29, 2024 at 2:55 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 50

Section/Table/Figure Number: Normative Appendix B / Rated Feature: Wall Exposure/Orientation

Comment Intent: Objection

Comment Type: Editorial

Comment:

Propose adding a footnote indicating that “a site survey certified by a qualified professional i.e., professional surveyor, may be used in lieu of on-site verification by the rater/verifier.

Proposed Change to Amendment:

Add footnote #_ “a site survey certified by a licensed/qualified professional may be used in lieu of on-site verification”

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

 

Entry Date: January 29, 2024 at 2:57 PM

Full Name: Cindy Zeis

Affiliation: Northeast Home Energy Rating Systems Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 58

Section/Table/Figure Number: Rated Feature: On-Site Battery Storage Systems

Comment Intent: Objection

Comment Type: Technical

Comment:

Although we anticipate seeing more on-site battery storage systems being installed, it may be premature to include this in the standard as there are no current approved databases for obtaining this information. The rater/verifier would be tasked with collecting data solely from the manufacturer which may be limited. This information needs to be centralized and easily obtained to ensure modeling consistency.

Proposed Change to Amendment:

Remove “On-Site Battery Storage Systems” from the on-site inspection protocol until a certifying agency has been identified to verify the efficiency of these units such i.e., ENERGY STAR®, AHRI, etc.

 

Rated Feature Task On-Site Inspection Protocol
On- Site Battery Storage Systems

 

Data collection for On-Site Battery Storage systems On-Site Battery Storage systems – Collect documentation that shows the battery storage system type, its maximum kW charge and discharge rates, its usable kWh capacity, and its round-trip efficiency.

 

This proposal is being issued on behalf of the Standards Committee of the Northeast Home Energy Rating System Alliance, which represents more than 260 Raters and 11 Providers from New Jersey to Maine.

Entry Date: January 29, 2024 at 3:29 PM

Full Name: Cindy Zeis

Affiliation: PSD

Address: 950 Danby Road Suite 201P Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: 1

Section/Table/Figure Number: Definitions

Comment Intent: Not an Objection

Comment Type: Technical

Comment:

Battery Storage Losses – Charging and discharging energy losses calculated as total annual energy based on the round-trip efficiency for the On-Site Battery Storage system.

  1. Clarification of “on-site battery storage” definition to include what an “electrical energy storage system” includes.
    1. Is the term “system” here defined as the battery storage unit only or the system as coupled with the PV system? I believe this should include the entire system as outlined in the example in item 3 below.
  2. Are we using the listed round-trip efficiency of the battery storage unit (BSU) or accounting for the total round-trip efficiency of the PV system inverter (DC to AC efficiency) and the BSU (AC to AC efficiency).
    1. Example: BSU efficiency 90% coupled with Inverter efficiency 97% = System round-trip efficiency 87.3%.
  3. Should a derate factor be applied for installations in climate zones where ambient temperatures exceed the limits of testing temperatures (~75-100°F)?
  4. Should we be paying more (or equal) attention to the sizing of these storage systems since this could greatly affect the efficiency of the system overall?
  5. This may be good for typical residential battery storage units but discounts site-built units that may include multiple battery storage units.

Proposed Change to Amendment:

Recommend striking this entirely and provide some context for a future amendment if/when battery technology & associated data is more readily available.

 

Alternative Recommendation: If it has already been determined that this language is needed for clarification of already approved changes an alternative recommendation is as follows:

 

If including the round-trip efficiency (RTE) as a means for determining BSL, the RTE should include the total system round-trip efficiency which includes the labeled RTE of the battery storage unit and the PV inverter efficiency when coupled with a PV system. System round-trip efficiency calculations could be made by the software utilizing modeler inputs of PV inverter efficiency (already available) multiplied by the labeled battery storage unit efficiency (new modeler input).

BSL = Battery Storage Losses, calculated as total annual energy based on the system round-trip efficiency.

Add Definitions:

Unit Round Trip Efficiency – The labeled efficiency of the battery storage unit.

System Round-Trip Efficiency: The labeled efficiency of the battery storage unit x the PV inverter efficiency. Example: BSU efficiency 90% coupled with Inverter efficiency 97% = System round-trip efficiency 87.3%.

Entry Date: January 29, 2024 at 4:58 PM

Full Name: London Swango

Affiliation: Building Efficiency Resources (BER)

Address: PO Box 1769 Brevard, North Carolina 28712

Phone Number: 800-399-9620

Email: HERS@theBER.com

Page Number: 43

Section/Table/Figure Number: 4.4.4.1

Comment Intent: Objection

Comment Type: General

Comment:

With newer systems being rated in SEER2 and HSPF2, it is unnecessary to require conversion to SEER and HSPF. Rating software should allow inputs of either SEER, SEER2, HSPF, or HSPF2 and should adjust accordingly. Requiring a conversion on the Rater’s side will only lead to more confusion and inaccuracies.

Proposed Change to Amendment:

For Heat Pumps and Air Conditioners with the more recent Manufacturer’s Equipment Performance Ratings (HSPF2 or SEER2) available, and HSPF or SEER are not available, these ratings shall can be converted to HSPF or SEER values by dividing HSPF2 or SEER2 by the conversion factors in Table 4.4.4.1(1). If the type of equipment is not determined, the conversion shall default to the “Ducted Split System” factors. All calculations, including Equation 4.1-1a, shall can use either HSPF, HSPF2, SEER, or SEER2 values as made available by the Manufacturer or converted as specified in this section.

Entry Date: January 29, 2024 at 5:02 PM

Full Name: London Swango

Affiliation: Building Efficiency Resources (BER)

Address: PO Box 1769 Brevard, North Carolina 28712

Phone Number: 800-399-9620

Email: HERS@theBER.com

Page Number: 51

Section/Table/Figure Number: Building Element: Wall Assembly

Comment Intent: Objection

Comment Type: General

Comment:

Finding orientation of the walls should be standardized using the front door and thus, the front of the house.

Proposed Change to Amendment:

Determine orientation of at least one exterior the front facing wall and record orientations of all exterior walls to the nearest cardinal/ordinal points.  First make sure the compass is not noticeably affected by steel members or electric current in the place you are standing. While standing in front of an exterior wall the front door inside the Dwelling Unit, record orientation while facing the exterior. When using a compass while standing outside the Dwelling Unit, record orientation while standing with back to the exterior wall. front door.

Tips and Reminders for Submitting Public Comments 

  • Comments must pertain to text in draft PDS-01 that is shown as either strikethrough or underlined and red print. Comments on portions of draft PDS-01 where no change is indicated will be rejected.
  • Comments should include a specific proposed change to the text of the draft open for comment. Proposed added text must be underlined and text proposed to be removed must be shown using strike-through. If not submitted in this format, the public comment may be rejected.
  • Do not submit comments on standards other than this one that is out for public comment.
  • If you submit public comment representing the collective interests of a group of stakeholders, you are encouraged to submit ONE public comment and identify all stakeholders in that comment. While not required, this expedites the ability of the committees to respond to commenters in a timely manner.
  • Public comments are reviewed by committees with volunteer members, that are Raters, Providers, Software Developers and other industry and public interest stakeholders. They are not reviewed by RESNET® Staff.
  • Most amendments to RESNET® standards are proposed by industry and public stakeholders not RESNET®. To learn more about submitting proposed amendments visit this page: https://www.resnet.us/about/standards/submit-proposed-amendments/