With new HVAC standards effective January 1, 2023, EnergyGauge and other software products needed either new detailed models or conversions to continue using the current models. With little to no newly labeled systems available in early 2022 for researchers to obtain empirical data, the only possible tact was to try a conversion. RESNET, concerned with software consistency, circulated proposed conversions to the approved HERS software vendors including EnergyGauge. FSEC used those conversion factors in the EnergyGauge update that was submitted and approved in the summer of 2022 for the 2022 Supplement to the 2020 7th Edition Florida Building Code, Energy Conservation. Note that these conversion factors are for modeling and there is no equivalent for compliance: Manufacturers must comply with the new testing and labeling to comply with the new standard. Where the standard indicates newly labeled systems must be installed, then only systems with the new SEER2 labels can be installed.
These conversion factors are implemented in EnergyGauge 7.5.0 for the purpose of modeling:
Small Duct High Velocity
For split systems, here are sample cooling and heating efficiencies converted per the factor shown:
SEER 2 entered
Note that for the 2022 Supplement to the 2020 7th Edition Florida Building Code, Energy Conservation, the R405 residential performance method for someone entering a fossil fuel furnace with a central air conditioning system is stricter. The Florida standard reference home is now modeled with an air conditioner meeting the new federal SEER2 standard (14.3 for systems less than 45,000 Btuh; 13.8 SEER2 for larger systems). For the systems under 45,000 Btuh this means a SEER of 15.05263 is being modeled in the standard reference home instead of a SEER 14 under the pre-supplement code.
The conversion factors first circulated by RESNET were further vetted and slight changes were made by the time RESNET passed an amendment in December 2022; however, no changes were made to split system conversion factors. The values shown above remain the conversions in EnergyGauge 7.5.
The NAHB has put together a document indicating the new standard and the corresponding old label metric: https://www.nahb.org/blog/2022/05/upcoming-changes-efficiency-standards-ac-units-heat-pumps
Code of Federal Regulations – scroll down at the link below until you see the following “Central air conditioners and central air conditioning heat pumps manufactured on or after January 1, 2023, must have a Seasonal Energy Efficiency Ratio 2 and a Heating Seasonal Performance Factor 2 not less than:” https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-430/subpart-C/section-430.32