Efficiency
SEER2, HSPF2, and AFUE: HVAC Efficiency Ratings Explained
Efficiency ratings tell you how much useful heating or cooling you get for the energy you pay for. Higher is better — but the right number depends on the equipment type and your climate.
SEER2 — cooling efficiency
SEER2 (Seasonal Energy Efficiency Ratio 2) measures the cooling efficiency of air conditioners and heat pumps over a season. As of 2023, SEER2 replaced the older SEER under updated test conditions, so don't compare a SEER2 number directly against an old SEER number. Minimum allowed SEER2 varies by region.
HSPF2 — heat pump heating efficiency
HSPF2 (Heating Seasonal Performance Factor 2) measures how efficiently a heat pump heats over a season. If you're buying a heat pump, this number matters as much as SEER2 — especially in colder climates.
AFUE — furnace efficiency
AFUE (Annual Fuel Utilization Efficiency) applies to furnaces and is shown as a percentage. An 80% AFUE furnace turns 80% of its fuel into usable heat; a 96% furnace turns 96% into heat. That difference shows up on every gas bill for the life of the system.
Higher-efficiency equipment usually costs more up front. Whether it pays back depends on your climate, energy prices, and how long you'll stay — a good analysis weighs efficiency against price rather than assuming higher is always worth it.
When a quote lists only “high efficiency” without a specific SEER2, HSPF2, or AFUE number, that's a gap worth questioning — you can't compare what isn't stated.
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