Most North Americans treat their air conditioners like a light switch. Hot? Turn it on. Cold enough? Turn it off. Pay the bill at the end of the month and don’t think about it.

That works fine, but it leaves a lot on the table—comfort, money, and the quiet satisfaction of running a household with a more positive impact on Earth. This week’s step is to swap out the light-switch approach for a wiser strategy where your air conditioner control is the last tool you reach for, not the first.

This step sits squarely on the Energy pathway—the set of practices that help us use energy more efficiently and shift the energy we do use toward cleaner sources. Cooling is worth attention here because its share of energy consumption is growing.

The U.S. Energy Information Administration’s most recent Residential Energy Consumption Survey put residential air conditioning at about 254 billion kilowatt-hours nationally each year, far more than our data centers (estimated at about 183 billion kWh in 2024), even after the recent buildup due to artificial intelligence. Nearly 9 out of 10 American households now run AC, up from 27% in 1980 with central air. When households trim just a few percentage points from their summer cooling loads, the load on our public power grid eases, peak-hour blackouts grow less likely, and the air stays a little cleaner for everyone who breathes it. None of the steps below asks anyone to suffer in a hot house. They just ask for some forethought that makes cranking down the thermostat less necessary.

The Order Matters

The reason most homes overspend on cooling isn’t that they run the AC. It’s that the AC does unnecessary work. Think of summer cooling as a stacked strategy with four layers, with the air conditioner sitting on top.

1. Stop the heat from getting in. Roughly a third of summer heat gain in a typical home comes through windows. The Department of Energy reports that smart use of window coverings can reduce that heat gain by up to 77 percent. Awnings on west-facing windows alone can cut solar heat gain by about 75 percent. Properly fitted cellular shades block up to 60 percent. DOE field studies of optimized interior and exterior shades have shown whole-home summer cooling savings of 15 to 25 percent. Most of this is free or nearly so. You probably already own blinds or curtains. The question is whether you have a plan and a practice to close them on the south and west sides of the house during the hottest part of the day.

2. Let the night do the work. In any climate where overnight temperatures dip below about 70°F, your house can let out the heat every evening. Open the windows after sundown, let the cool air in, and close them in the morning before the heat builds. A 2015 Lawrence Berkeley National Laboratory study of residential ventilation cooling found that nighttime ventilation strategies could save more than 2,000 kilowatt-hours of cooling energy per year in mixed-climate zones and reduce peak-period compressor use by 40 to 50 percent in California field tests. The technique has limits—it doesn’t work well in humid climates where pulling moist air in at night creates worse problems than it solves—but for much of the country, opening the windows at 9 p.m. is the cheapest cooling decision you can make.

3. Move the air around you. Ceiling fans don’t cool rooms. They cool people. The wind-chill effect from moving air lets you stay comfortable at a higher thermostat setting, and that is the entire savings. Leave both your fan and your AC off when you’re not around to enjoy them. Turn them both on when you need them. Research from UC Berkeley’s Center for the Built Environment found that pairing smart ceiling fans with higher setpoints delivered 39 percent compressor energy savings during the cooling season across multiple field sites, and that every degree of setpoint increase reduces HVAC energy use by roughly 5 to 7 percent. DOE estimates each degree above 72°F saves about 3 percent on cooling costs. A ceiling fan on low draws 15 to 30 watts, while your air conditioner pulls thousands of watts when the compressor cycles on. We covered the winter side of ceiling fan use in The Warmest Air in Your House Is Trapped at the Ceiling; the summer setting for the same fan has the blades spinning the other direction, pushing air down.

4. Tune up what you do run. Central air conditioners and heat pumps drift downward in efficiency a few percent each year, while many owners notice nothing. Two steps this week prevent that insidious waste. First, replace the air filter. DOE estimates that swapping a clogged filter for a clean one can reduce an AC’s energy consumption by 5 to 15 percent. Second, walk outside to the condenser unit, pull weeds and clear leaf litter from around it, and gently rinse the fins with a garden hose from top to bottom (power off first). Vegetation crowding the unit or a dirty coil forces the compressor to work harder for the same cooling. If you haven’t had a professional service visit in two years or more, schedule one. Heat pump owners: spring is your tune-up season too, because your unit is about to spring back into action in cooling mode.

Your One Step This Week

Walk to your thermostat. Raise the setpoint by three or four degrees from wherever you usually have it. Then pair that one decision with one supporting move that makes the new setting bearable: close the west-facing shades in the afternoon, run the ceiling fans in cooling mode (pushing air down, not sucking air up), replace the filter, or open the windows tonight before bed. Pick the one you can do today. Add another next week. The DOE’s specific guidance—78°F at home, up to 85°F when you’re out—is a useful target, but the most important number is whatever gives you relief from the heat.

If windows and fans don’t get your house comfortable when the real heat arrives, then run the AC—just run it less, in a house where less is more than enough.

For more on the Energy pathway and dozens of other science-based practices, visit www.suspra.com or pick up a copy of the Sustainable Practices: Your Handbook for Effective Action. Our April 26 article Plant One Tree, Cut Home Energy Use covers the longer-term version of step one: shading your house with deciduous trees. And Your Home Deserves a Manual lays out the seasonal maintenance approach that keeps all systems working at peak performance year after year.

References and Resources

Primary Research

U.S. Energy Information Administration. “How much electricity is used for air conditioning in the United States?” Residential Energy Consumption Survey (RECS) 2020.
https://www.eia.gov/tools/faqs/faq.php?id=1174

Raftery, P., Bauman, F., Schiavon, S., et al. “Cooling energy savings and occupant feedback in a two year retrofit evaluation of 99 automated ceiling fans staged with air conditioning.” Energy and Buildings (2021). Center for the Built Environment, UC Berkeley.
https://cbe.berkeley.edu/research/epic-integrating-smart-ceiling-fans-study/

Less, B., Walker, I., Tang, Y. (2015). “Development of an Outdoor Temperature-Based Control Algorithm for Residential Mechanical Ventilation Control.” Lawrence Berkeley National Laboratory, LBNL-180960.
https://eta-publications.lbl.gov/sites/default/files/lbnl180960.pdf

Cort, K., et al. “Window Attachments for Solar Control and Energy Efficiency.” Pacific Northwest National Laboratory / DOE Building America Solution Center.
https://basc.pnnl.gov/resource-guides/window-attachments-solar-control-and-energy-efficiency

ANSI/ASHRAE Standard 55-2023: Thermal Environmental Conditions for Human Occupancy. American Society of Heating, Refrigerating and Air-Conditioning Engineers.
https://www.ashrae.org/technical-resources/bookstore/standard-55-thermal-environmental-conditions-for-human-occupancy

Authoritative Resources

U.S. Department of Energy — Programmable Thermostats (set-point and setback guidance)
https://www.energy.gov/energysaver/programmable-thermostats

U.S. Department of Energy — Air Conditioner Maintenance
 https://www.energy.gov/energysaver/air-conditioner-maintenance

U.S. Department of Energy — Energy Efficient Window Coverings
 https://www.energy.gov/energysaver/energy-efficient-window-coverings

U.S. Department of Energy — Fans for Cooling
 https://www.energy.gov/energysaver/fans-cooling

ENERGY STAR — Heat and Cool Efficiently
 https://www.energystar.gov/saveathome/heating-cooling

Related One Step Articles

Plant One Tree, Cut Home Energy Use — strategic tree placement for cooling and windbreaks (April 26, 2026)

The Warmest Air in Your House Is Trapped at the Ceiling — ceiling fan direction and thermal stratification (February 1, 2026)

Your Home Deserves a Manual — building a home maintenance log that catches efficiency drift (February 22, 2025)

Chill Without the Bill: Sustainable Cooling — last year’s broader look at passive cooling (June 29, 2025)

This article explores a step on the Energy pathway—one of seven pathways to sustainability in the Sustainable Practice framework. To expand your positive impact on Earth, join Sustainable Practice as a Core or Complete Member.