Air Conditioning Limbo – How Low Can You Go?

We can’t seem to help ourselves. We push the elevator button even though it’s already lit. It’s the same thing with the thermostat. We crank the thermostat down to arctic temperatures in the hopes that it will cool faster. I don’t know if it is misplaced optimism or simple impatience that motivates us. I suppose it makes us feel like that at least we’re doing SOMETHING to make things happen. I can’t speak for the elevator, but I can tell you that playing the Air Conditioning Limbo game (How low can you go!) can actually damage your AC unit. So QUIT IT!

I found the picture below on Pinterest and thought it was hilariously on point. Though I have a couple of issues with it. The first issue being that it is set really high for the warning. You should be able to get a LOT lower than the setting shown without freezing up the unit. I also think “die” might be overstating a bit. I don’t know the exact circumstances of the photo. This thermostat may be located in hell…Pinterest didn’t say. But the gist of it is true: an AC unit CAN freeze up if it is set too low.

Tstat too low

The typical AC unit uses refrigerant and compressors designed for medium temperature refrigeration. Unlike low temp refrigeration systems, like your freezer, your AC unit is not designed to take your space into freezing temperatures – not even close! An AC unit is happiest creating space temperatures no lower than 68 degrees fahrenheit. I know some of you out there are all, “I keep MINE at 66 and it’s FINE!” OK, sure, but you’re walking the line, tempting fate and living dangerously. If that’s your jam, proceed if you must.

At lower temps, the unit can freeze up – which literally means having ice or frost form on the coils and/or piping. Though I’m sure some of you are saying, “YES, freezing sounds great! Exactly what I was going for.” Unfortunately, a frozen AC unit cannot effectively cool your space, or you, and it can damage your compressor. So you’ll still be hot and your thermostat limbo may result in a significant repair bill, or early death of your AC unit, which are definitely NOT great.

There are other potential causes of your unit freezing including insufficient air flow (dirty filter, broken fan, blocked or dirty coils, etc.) or insufficient refrigerant in the system. These are issues that are usually addressed during your annual maintenance visit. If you find your AC unit frozen or frosted, the first thing to check is your thermostat setting. If you got antsy and lowered it below the 68 degree threshold, shame on you! Turn the cooling off, leave the fan on, let the unit melt. When you turn it back on DON’T put it below 68! If the thermostat setting is within normal range and your unit is still freezing up, or you’re not getting cool enough, check your filter. If that’s clean, it’s probably time to call your trusty AC technician because something more serious is afoot. By having the unit checked out at the first signs of trouble, you could save yourself the cost of a larger repair later and avoid serious damage to your unit.

So, if it makes you feel better, go ahead and push that elevator button twice. But stop messing with your thermostat, or we’ll have to come over there and lock it on you!