Genius House Hacks · a GopherCentral & PulseTV publication
Home Comfort & Energy · May 13, 2025 edition

10 Air Conditioning Mistakes You Can't Afford to Make

From the Genius House Hacks archive.

Genius House Hacks

When summer hits and the heat is relentless, your air conditioner becomes your best friend. But just like any good friendship, it works best when you treat it right. A lot of people unknowingly make simple mistakes with their A/C that lead to higher energy bills, unnecessary repairs, and even total system failure — here are some common ones to avoid.

Forgetting to Change the Air Filter

A clogged filter can seriously mess with your system — when it's dirty, your A/C has to work harder to push air through, meaning less cool air for you and more stress on the unit. Check it once a month and change it when it looks dirty.

Setting the Thermostat Way Too Low

Slamming the thermostat down to 60 hoping your place will cool off faster doesn't work that way — the A/C cools at a set pace, so all you're doing is making it run longer and use more energy.

Skipping Maintenance

Your A/C needs a little TLC now and then, just like a car — it runs better and lasts longer with regular checkups. Having a pro look at it once a year can help catch small problems before they turn into big, expensive ones.

Cooling Empty Rooms

If no one's using the guest bedroom, there's no need to keep it icy cold. Close the vents and shut the door, and focus your cooling power where it actually matters.

Blocking Vents with Furniture

If your couch, bed, or bookshelf is sitting over a vent, you're preventing cool air from circulating properly. It's a quick fix that can make a big difference.

Ignoring the Power of Ceiling Fans

Fans don't cool the air, but they sure make it feel cooler. Using a ceiling fan with your A/C lets you raise the thermostat a few degrees and still feel comfortable, while helping move the air around so your home cools more evenly.

Letting the Sun Heat Things Up

Leaving blinds or curtains open during the hottest parts of the day basically invites in more heat, making your A/C work even harder. Keep the sunlight out during peak hours and you'll notice the difference.

Having the Wrong-Sized A/C Unit

Bigger isn't always better — an oversized unit might cool quickly, but it won't run long enough to remove humidity, leaving you with a cold but clammy house. A unit that's too small will just run constantly and still leave you sweating. The right size matters.

Putting the Thermostat in a Bad Spot

A thermostat near a window or a heat-producing appliance gets a false read on the room's temperature, which can cause the system to turn on or off when it shouldn't. Keep it in a central, shaded spot for the most accurate reading.

Leaving the A/C Running All Day

If you're out of the house for hours, there's no need to keep it icy cold the whole time. A programmable or smart thermostat can turn things up just before you get home, saving energy without sacrificing comfort.

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