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10 CFR §431.76

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Scope. This section prescribes the test requirements used to measure the energy efficiency of commercial warm air furnaces with a rated maximum input of 225,000 Btu per hour or more.
  2. (b)Testing and calculations—(1) Thermal efficiency. Test in accordance with appendix A to subpart D of this part when making representations of thermal efficiency.
    1. (2)Thermal efficiency two. Test in accordance with appendix B to subpart D of this part when making representations of thermal efficiency two.