Efficiency comparison
Higher SEER ratings generally lower electricity use for the same cooling output. Compare ratings before estimating monthly AC cost or replacement savings.
| SEER range | Efficiency signal | Best use in calculator |
|---|---|---|
| 8-10 | Older, less efficient systems | Useful baseline for replacement savings. |
| 11-13 | Moderate older systems | Compare against modern options. |
| 14-16 | Common efficient range | Good default when exact rating is unknown. |
| 17+ | High efficiency | Compare purchase cost against annual savings. |
SEER compares seasonal cooling output to electricity input. If two AC systems cool the same home for the same number of hours, the higher-SEER system should use less electricity.
SEER is not the only factor. Duct leakage, refrigerant charge, thermostat setting, insulation, and climate can change actual cost. Use the calculator as a planning estimate, not a utility bill guarantee.