Micah Pollak had no idea the trouble he was getting himself into when he shared his preferred thermostat settings on social media. “I just discovered most of our friends set their AC at 68-73F during the summer,” Micah, who is an economist at Indiana University, posted on Threads in last June. “We keep ours at 77-78F. Are we monsters!?” Nearly a thousand replies later, the consensus was that, yes, Micah’s family are monsters, probably some type of lizard.
Although he didn’t realize it, Micah has been following a set of numbers from the Environmental Protection Agency that tends to spark an internet freakout every summer, often after a local news station does a segment on how to reduce your energy consumption and lower your utility bills. The recommendations include keeping your thermostat at 78º when you’re at home during the day, 82º at night, and 85º when you’re away during the warm months.
To many people, sleeping in 82º heat is simply outrageous. (Not to mention terrible for your sleep, according to experts.) But energy prices are crazy too, and they’re only expected to rise as utility companies spend more and more to make the grid more resilient to the effects of climate change. Extreme weather events are becoming more common, and heat waves in particular can strain the power grid, especially when thousands of people are running their ACs at full tilt.
So maybe cranking up your thermostat isn’t such a bad deal. Typically, I’m inclined to set my AC to 72 on a really hot day. If I could get used to a balmy 78º inside, I’d not only save money, I’d be doing my part to keep the grid running smoothly so that everyone can enjoy a little bit of air conditioning, too. And the savings are real. The EPA says that for every degree warmer you set your AC, you can save 6 percent on your cooling costs, although you get diminishing returns as you go higher and higher. Put simply, if your cooling bill is usually $170, setting your thermostat a single digit higher will save you over $10 a month.
There’s one big problem, though. That 78º baseline isn’t a real federal government recommendation. The EPA’s Energy Star program does have a guide for programmable thermostat settings, but it doesn’t recommend a specific number to set your thermostat to in the summer. The numbers that show up in the news actually come from a table in a 2009 document that offered examples of what energy-saving settings could look like.
“Your household temperatures are very much a personal choice, and ultimately people should do what makes them comfortable,” Leslie Jones, a public affairs specialist from Energy Star, told me.
The agency’s official position is that you can save “up to 10 percent on heating and cooling settings by simply turning your thermostat 7°-10°F for 8 hours a day from its normal setting.” In other words, if you keep it at 71 while you’re home, go ahead and set it to 78 if you leave for the day.
Then again, setting your thermostat at 78º at all times is not a monstrous idea. And setting it at 72º probably means you’re wasting some energy.
Nobody wants the government telling them to suffer more in the summer heat. A lot of our assumptions, though, about how air conditioning works, how to optimize the effectiveness of this century-old technology, and how to save energy in the process are just that: assumptions. To clear up the outrage over where we set out thermostats, I talked to experts in thermal comfort, HVAC technology, and the built environment.
It turns out, some of the most effective ways to stay cool are both simple and cheap.
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—Adam Clark Estes, senior technology correspondent
