During my childhood summers, leaving the house was a process: Turn off the AC, dash to the door, and close it as quickly as possible to minimize the loss of cooled air.
Those old energy-saving habits can be hard to break—I’ve only recently accepted that it’s okay to leave the lights on when I’m not in a room.
It got me wondering: Is it really worth it to shut off the AC when you leave the house?
I’ve been testing at least a dozen AC units every year since 2019, and air-conditioner efficiency has come a long way since the summer when ska was popular. So I ran some tests.
As it turns out, the most efficient way to keep your home cool and the bills low is to leave the AC running—ideally, with the temperature turned up toward the upper 70s.
