Compare air-conditioner efficiency ratings, estimate annual cooling electricity savings, and see how long an AC upgrade may take to pay for itself.
Two systems delivering the same annual amount of cooling, with different SEER2 ratings. The default inputs are examples, not actual utility rates, equipment prices, or verified cooling hours. This is a cooling-electricity estimate—not a replacement quote, a heating calculator, or an HVAC load calculation.
Higher SEER2 ratings generally represent lower seasonal electricity use for the same cooling delivered. But the value of an upgrade depends on your cooling load, regional usage, electricity price, and the additional amount you must pay for the upgrade.
SEER2 (Seasonal Energy Efficiency Ratio 2) measures the total seasonal cooling delivered in BTUs divided by the electrical energy consumed in watt-hours. A higher number means less rated energy use for the same quantity of cooling. SEER2 replaced the older SEER testing method for newly rated equipment beginning in 2023.
If you're replacing an AC anyway, compare the additional price of the efficient model with a standard new model. If your current AC still works and you're considering replacing it early, compare the full cost of the new installation with savings against keeping the current system. These are different decisions, so they should not use the same investment figure.
Equivalent full-load hours describe the annual cooling output as if the system ran at rated capacity. For example, 1,600 equivalent hours at 36,000 BTU/h is 57.6 million BTUs of modeled cooling. Actual on/off runtime and variable-speed operation will differ. Replace the example with a local estimate whenever possible.
No. If the energy savings are small relative to the incremental purchase price, the energy-only payback period may exceed the expected service life. Comfort, humidity control, noise, installation quality, warranty, and reliability also matter, but this tool deliberately does not assign dollar values to them.
Cooling capacity: Tons × 12,000 = BTU per hour.
Modeled seasonal cooling output: BTU per hour × equivalent full-load hours = BTU per year.
Annual electricity (kWh): Seasonal cooling BTUs ÷ SEER2 ÷ 1,000.
Annual electricity cost: Annual kWh × electricity price per kWh.
Annual electricity savings: Baseline annual electricity cost − upgraded annual electricity cost.
Net investment: Applicable replacement/upgrade cost − confirmed applicable rebates. Rebates cannot exceed the compared investment.
Simple energy-only payback: Net investment ÷ annual electricity savings, when savings are positive. If savings are zero or negative, there is no energy-savings payback.
10-year net savings: 10 × annual electricity savings − net investment. Gross multi-year savings are the annual amount multiplied by the number of years.
The model assumes unchanged cooling demand and SEER2 ratings for the full period, constant electricity rates, and no discounting. All figures are planning illustrations, not guaranteed savings. A qualified HVAC contractor can evaluate equipment selection and building-specific loads.
Not directly in this tool. SEER and SEER2 are separate test methods. Enter ratings measured under the same SEER2 standard, or request a comparable SEER2 figure from the equipment manufacturer or contractor.
Select “Choosing a more efficient new AC” and enter only the extra cost of the higher-efficiency system—not the entire installation price. Include confirmed rebates only if they actually offset that incremental cost.
Select “Replacing a working AC now,” enter your current system's comparable SEER2 rating, and enter the full installed cost of the replacement. The model assumes your existing system remains available for comparison, which may not be realistic if it is near failure.
No. It estimates cooling electricity alone, not appliances, lighting, heating, fixed utility charges, and taxes. Weather, thermostat schedules, duct losses, and the system's actual performance can change real-world results.
No. The SEER2 figures here are used for cooling only. Heat pump heating efficiency is evaluated separately, commonly using HSPF2.
Reference reading: U.S. Department of Energy · Residential Central Air Conditioners and ENERGY STAR · SEER2 Definitions.
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