DOE proposed amending its test procedure for commercial warm air furnaces (CWAFs), as adopted under the Energy Policy and Conservation Act (EPCA), by rescinding Appendix B, “Uniform Test Method for Measurement of the Energy Efficiency of Commercial Warm Air Furnaces (Thermal Efficiency Two).” DOE tentatively determined that Appendix B is “unduly burdensome to conduct,” thereby failing to meet the statutory criteria for adoption of a test procedure. Commercial warm air furnaces will continue to be subject to the testing requirements of Appendix A, “Uniform Test Method for Measurement of the Energy Efficiency of Commercial Warm Air Furnaces (Thermal Efficiency).”
On January 17, 2025, DOE published a final determination in the Federal Register, concluding that its current test procedure failed to satisfy EPCA's statutory requirements, and that incorporating the Thermal Efficiency Two (TE2) metric was justified under the applicable statutory criteria. 90 FR 5560. However, DOE now stresses its new policy to “reduce regulatory burden wherever possible.” Under that policy, DOE reviewed its own recent reasoning and found that the January 17 final determination preceded from insufficient evidence to support adoption of the TE2 metric, and overestimated the impacts of jacket losses and part-load operation on CWAF energy use.