RODALE NEWS, EMMAUS, PA—We’ve all wondered this at some point, usually after coming home to a stifling house on a long, hot, summer day: Do you save energy by shutting off your air conditioner when you’re gone for the day? Or is it better to just let it run at the same temperature setting all day long, so you don’t expend extra kilowatts starting it up and getting the premises to a comfortable temperature? Wasting energy not only costs you more money, it leads to more burning of coal and other fossil fuels that contribute to global climate change. We contacted Jennifer Thorne Amann, MES, buildings program director for the American Council for an Energy-Efficient Economy (ACEEE), to help us figure it out.
THIS: Leave the AC running, set at the same temperature all day.
The theory: If you leave the AC running with the temperature set at a comfortable setting, the stable temp means the air conditioner won’t have to work as hard.
THAT: Turn the AC off when you leave; turn it on when you get home.
The theory: If you let the house get hot when you’re away, the air conditioner will use more energy when it’s time to cool things down.