HVAC Energy Saving Tips: 14 Ways to Cut Heating and Cooling Costs (2026)

Heating and cooling are the largest energy users in most homes, about 32% of household energy use according to the DOE. The tips below are the ones the DOE and ENERGY STAR attach numbers to, roughly in order from free to bigger projects.

The biggest low-cost savings come from thermostat setbacks (as much as 10% a year, per the DOE), sealing air leaks (10% to 20% on heating and cooling bills) and clean filters (5% to 15% lower air conditioner energy use). Sealing leaky ducts, adding insulation and replacing old equipment save more but cost more.

What these tips save in dollars

The percentages above apply to different bases, so one worked example ties them to money. A home at the U.S. average electricity use of 10,356 kWh a year pays about $1,864 at $0.18 per kWh (10,356 × $0.18). Because the DOE puts heating and cooling at about 32% of household energy, the heating-and-cooling share of an all-electric home at that use is near $597 a year (0.32 × $1,864).

Against that $597 base, a 10% thermostat setback saves about $60 a year (0.10 × $597). Air sealing at 10% to 20% saves roughly $60 to $120, and low-e storm windows at 10% to 30% save about $60 to $180 depending on the windows they replace. Sealing leaky ducts, worth as much as 20% of efficiency, saves up to about $120.

Clean filters cut 5% to 15% of air-conditioner energy, which is the cooling slice of that total rather than the whole $597. To size any of these for your own home, multiply your yearly heating-and-cooling spending by each percentage.

The table ranks the quantified tips by their high-end savings on that same $597 example, so the biggest potential wins sit at the top.

Free and quick

1. Set back the thermostat. Turning it down 7 to 10°F for 8 hours a day in fall and winter can save as much as 10% a year, according to the DOE; with a heat pump, use a thermostat designed for heat pumps.
2. Use ceiling fans in summer. The DOE says a ceiling fan lets you raise the thermostat about 4°F with no loss in comfort; turn fans off when you leave the room.
3. Use window coverings. Close them on sunny summer days, and open south-facing ones on winter days to let in the sun's heat.
4. Set the fan to Auto. The DOE recommends Auto rather than On, unless your system is set up to run continuously for air quality.
5. Turn off exhaust fans within about 20 minutes after cooking or bathing, as the DOE suggests.

Low cost

6. Change filters. The DOE says clean filters can lower an air conditioner's energy use by 5% to 15%; check them monthly in heavy-use seasons. See how often to change your filter.
7. Seal air leaks. Caulking and weatherstripping can save 10% to 20% on heating and cooling bills, according to the DOE.
8. Program it once. A programmable or smart thermostat makes setbacks happen daily; see smart thermostat savings.

Bigger projects

9. Seal and insulate ducts. ENERGY STAR says leaky ducts can reduce heating and cooling efficiency by as much as 20%; see duct leakage testing.
10. Add insulation to ENERGY STAR's recommended levels for your climate zone; see the insulation R-value guide.
11. Add storm windows. Low-e storm windows can save 10% to 30% on heating and cooling, depending on your existing windows, according to the DOE.
12. Get a pre-season tune-up, the cooling system in spring and heating in fall, as ENERGY STAR recommends.

Replacing equipment

13. Know the replacement signals. ENERGY STAR suggests considering replacement when a heat pump or air conditioner is more than 10 years old, or a furnace or boiler more than 15; see HVAC system lifespan.
14. Choose efficient equipment. ENERGY STAR says its certified furnaces are 15% more efficient than conventional models, and the DOE says heat pumps can cut heating electricity by about half compared with electric furnaces and baseboard heat.

Where the biggest savings come from

Grouping the tips three ways shows the building shell carrying the largest single percentages. Sealing and insulating the shell (air sealing, duct sealing, insulation, storm windows) holds the 10% to 30% ranges above. Equipment choices and daily behavior each save real money too, usually in smaller slices, with the exception of replacing electric resistance heat with a heat pump.

Summer and winter quick actions

In summer the aim is to keep heat out and move air across your skin. Raise the thermostat and run ceiling fans so the blades push air straight down, which creates a draft that feels cooler and supports setting the thermostat about 4°F higher. Close window coverings on sunny days, and book the cooling tune-up in spring.

In winter the aim is to hold heat in. Set the thermostat back 7 to 10°F for the 8 hours you are asleep or away, and run ceiling fans slowly in reverse so they pull cool air up and roll warm air down off the ceiling without a draft. Open south-facing coverings on sunny days, close them at night, and book the heating tune-up in fall.

Frequently asked questions

What is the easiest way to save on heating and cooling?

Thermostat setbacks: the DOE says turning it down 7 to 10°F for 8 hours a day can save as much as 10% a year, at no cost.

Do ceiling fans save energy?

Yes, if you raise the thermostat while they run; the DOE says about 4°F with no loss in comfort. A fan in an empty room only uses electricity.

How much can air sealing save?

10% to 20% on heating and cooling bills, according to the DOE.

When should I replace my HVAC system?

ENERGY STAR suggests considering it after 10 years for a heat pump or AC and 15 for a furnace or boiler, especially with frequent repairs and rising bills.

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