Should You Leave the AC On or Off When Away? Experts Explain

It’s the summertime question everyone seems to ask: “Should I leave AC running while I’m gone, or turn it off to save money?” 

Air conditioning makes life bearable when temperatures soar, but it also racks up the biggest portion of our summertime electricity bills. 

And finding the sweet spot between comfort and savings can feel like a bit of a guessing game. Thankfully, energy experts have some clear advice on how to balance the scales.

Experts Reveal Best Way to Run Your AC Efficiently

If you’re heading out for a full workday, most experts agree that turning off the air conditioning or at least raising the thermostat several degrees is the better option. 

The U.S. Department of Energy says that adjusting your thermostat seven to ten degrees for about eight hours can help save up to 10% annually on cooling costs. That’s some real money shaved off your summer bills.

Of course, if you’re just running to the grocery store for 20 minutes, don’t bother fiddling with the thermostat. The energy savings won’t be noticeable, and your AC will likely kick back on before you’re even out of the parking lot. 

Why Leaving It On Might Make Sense

Still, the answer isn’t always one-size-fits-all. In very humid regions, completely shutting off your AC can backfire. That’s because your system doesn’t just cool, it also controls indoor humidity. 

Too much moisture in the air can lead to mold growth and make your house harder to cool when you return home. In those climates, experts say it’s better to raise the thermostat a few degrees instead of shutting the system down entirely.

Another thing to keep in mind is system strain. Air conditioners don’t reach peak efficiency until they’ve been running for 15 to 30 minutes. Constantly shutting it off and then demanding a rapid cooldown can wear out the parts faster. 

So, if you live in a humid or older, poorly insulated home, consider keeping it running at a higher setting during the day.

AC Efficiency Tips for Every Home

Whether you turn it off or let it hum along throughout the day, there are easy ways to boost your air conditioner’s efficiency. 

Close your curtains and blinds during the hottest part of the day. If it’s really bad, you can even use reflective window coverings or films to keep the sun out.

Insulation also plays a big role. Drafty houses warm up quickly, so adjusting the thermostat when you step out even for just a few hours may make a difference. 

Meanwhile, well-insulated homes with brick or concrete walls tend to hold cool air longer, meaning you don’t need to push the AC unit as hard. These small AC efficiency tips can add up to noticeable savings over time. 

Smart Tools to Save Energy on Air Conditioning

Technology can also do the heavy lifting. Smart thermostats like Nest or Ecobee automatically adjust temperatures based on whether you’re home. 

They can learn your schedule and bump the AC up when you leave, then cool things down before you return. According to some estimates, this can save us about 12% to 15% annually.

Window units, on the other hand, tend to be less efficient since they can’t seal out hot air as well as central systems. A quick fix is to apply weather stripping or spray foam around the unit to keep the cold air inside where it belongs. 

Small tweaks like this can improve efficiency and help reduce electricity bills from ACs.

Making Air Conditioning Work for You

So, what’s the verdict on the age-old AC on or off when away debate? The best approach depends on your climate, your home’s insulation, and how long you’ll be gone. 

As with most things in life, it’s all about moderation. Cranking it full blast all day is wasteful, but shutting it down completely may not be the best move, either. It may take a bit of trial and error, but it’s all about finding the sweet spot. 

With the right mix of small changes, you can save energy on air conditioning, reduce your electricity bills, and keep your home comfortable without unnecessary costs. That leaves a little extra wiggle room for one more weekend getaway before school starts up again.