16 CFR Part 305, Appendix G1 — Furnaces—Gas
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
| Furnace type | Range of annual fuel utilization efficiencies (AFUEs) |
|---|---|
| Low | High |
| Non-Weatherized Gas Furnaces—All Capacities | 80 | 99 |
| Weatherized Gas Furnaces—All Capacities | 81 | 95 |
[87 FR 61475, Oct. 12, 2022]