At the National Fenestration Rating Council’s (NFRC) Mid-Cycle virtual meeting NFRC membership approved ballot changes to eight of the 10 proposed ballots. Two were sent back to their respective committees for further review. The NFRC Board of Directors then approved those eight ballot measures so that the changes may be implemented. Here is a breakdown of the ballot measures and the changes that will occur.
NFRC 700 Subcommittee
NFRC 700 Glazing Description: This ballot changes the required information for the temporary label on certified products, making the glazing description optional instead of mandatory. The number of glass panes also has been added to the glazing description along with the tint colors into the single glazing description paragraph. Manufacturers that print a glazing description on their label may continue to do so, since there are no additional labeling requirements as a result of this ballot.
NFRC 700 Condensation Index: This ballot removes the NFRC 500 Condensation Resistance Rating (CR) and replaces it with the ANSI/NFRC 500 Condensation Index (CI). PCP participants that currently use the CR can continue to do so for the remainder of the product line’s certification. NFRC’s Certified Products Directory will need to be modified to incorporate the CI.
Condensation Resistance Subcommittee
ANSI/NFRC 500 and NFRC 501: These ballots further refine the new Condensation Index procedure to address comments that came from NFRC’s ANS Committee. This ballot changes the reference to the distance the glass edge temperature is to be taken. All documents and the software tool referencing the CI shall have consistent language that the glass edge temperature shall be obtained at 25mm and not 25.4mm. Language will be held in abeyance until the next approved ANSI balloting cycle.
ANSI/NFRC 100 Reporting Ratings: This ballot corrects the ANSI/NFRC 100 to remove reference to report metric U-factor to the nearest 0.05 W/m2K and strictly use proper rounding of the result to two decimal points. Per NFRC 700, there is no language that states metric rating of U-factor shall be rounded to the nearest 0.05 W/m2K but, consistently throughout the document it states that the U-factor rating shall be displayed on the NFRC label as rounded to two decimals.
The sample labels confirm that the metric U-factor is not required to be rounded to the nearest 0.05 W/m2K as shown in Figures A-5 and A-9. The U-factor in those sample labels show a metric U-factor of 1.99 W/m2K and is confirmed to match the I-P (Imperial) value of 0.35 Btu/hr/ft2/F. The conversion is calculated, as required by NFRC 700, as 5.678263. This conversion is the value used by the laboratories when converting metric to I-P in their reports as well as the CPD 2.0 Upload Spreadsheet.
Solar Heat Gain Subcommittee
ANSI/NFRC 200 Equation 4-3: This correction to the NFRC 200 makes the LEAFF program consistent with the calculations WINDOW uses. During the LEAFF program implementation, an error was discovered in the exterior heat transfer coefficient in Equation 4-3. The value of 30 W/m2K in the equation is for the winter conditions and the SHGC is calculated under summer conditions. The WINDOWS program from LBNL uses the summer exterior heat transfer coefficient of 20.6 W/m2K.
Research and Technology Committee
Thermophysical Properties of Materials Subcommittee
NFRC 101 Appendices: This ballot is intended to update the source references for the material properties listed in Appendices A and B and to update the properties based on those new references. This is a follow up to the ballot from the Virtual Spring Committee 2020 meeting. The default THERM materials library will be revised to incorporate the changed Appendices. The implementation plan for the new appendices is Jan. 1, 2021. Once implemented, the new data will be used for all new certifications, revisions, and addenda to existing product lines. All existing product lines and products in the CPD will be able to remain until the end of the certification cycle.
NFRC 101 Non-homogenous Spacer: This ballot revises Section 22.214.171.124 relating to conductivity measurements of non-homogeneous spacer samples. Four changes passed:
- An upper limit on the thickness of the foam rubber sheets.
- Test method revisions based on the laboratory equipment capability
- Specifying the removal of the contribution of the glass to the thermal resistance of the specimen
- Clarifying the reference to EN675.