On sweltering days, the temptation to crank the air conditioner can be as hard to resist as the siren song of the ice cream truck. But finding ways to keep your home cool without AC can ease both energy bills and emissions. In the U.S., AC alone accounts for about 17% of a home’s electricity consumption, and the average utility bill can jump by 8% as temperatures climb between June and September.
Blasting cool air from a conventional condenser is also one of the biggest contributors to greenhouse gases. About 3% of global emissions trace back to AC, nearly twice as much as those generated by the airline industry. And, as human-caused climate change spurs more frequent and intense heat waves, demand for indoor chillers could triple by 2050, according to a 2023 report from the United Nations.
Even when the temperature outside makes shutting off AC a hard “no,” it is totally feasible to dial down the thermostat a few notches. It might not always be possible to physically lower the temperature of your home, but making it feel cooler is. Doing so comes down to two things: harnessing the physics of airflow and heat transfer, and leaning into tactics that leverage your body’s natural cooling system. Many of these tricks are especially handy for renters looking to make their homes more efficient.
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If your home gets too hot during summer days and too cold during winter, poor insulation might be the culprit. “The most important thing is to make sure that that heat is not penetrating your home in the first place,” says the DOE’s Plog. “Air leaks are a really big source of energy loss.” Effective insulation can help you reduce your energy costs by about 11%, according to Energy Star, because it reduces any “heat leaks” going either in or out of the house. “Heat can either escape in the winter or come in through the summer. When you’re trying to cool your home and your AC is on full blast and the heat from outside is coming in, it’s going to increase your energy cost,” says Alison Knasin, lab manager at Indiana University’s Energy Justice Lab. “Insulation is good year round.”