How to Protect Your Window Air Conditioner over The Winter (Without Removing it)

Window air conditioners are one of the most amazing inventions of modern history.

Nothing is as wonderful as walking into a nice cool home from the sizzling heat of summer.

But as the days start to grow shorter and colder, you might be wondering what to do with your new window AC unit.

You’ve spent a lot of money putting in the new unit and you don’t want it to get damaged over the winter. So what should you do?

Your air conditioner’s manufacturer may have some recommendations, such as removing and storing it, but that’s not always possible.

If you can’t, or don’t want to remove your window air conditioner, you may be wondering if you can leave the AC unit in the window during the winter.

Yes, you can, however if you want to avoid damaging the unit, there are some precautions you must take.

Like any other electronic device, harsh weather conditions can damage window air conditioners. Water and ice can do a lot of damage over the winter, so it’s important to protect your window AC from the elements.

Not only can your unit get damaged, unless you have the AC unit well insulated, but the installation area could also become a cold spot in your home, increasing your heating costs.

How to cover your window AC unit

Measuring your window AC unit

If you plan to cover your window AC unit using a purchased cover measure the depth, height, and width of your window AC unit to ensure a good fit.

Before installing the cover read through the manufacturer’s directions to ensure proper installation.

DIY air conditioner cover

If you’re feeling really crafty, you can make your own using styrofoam and reflexive foil.

Alternatively, cover all sides of the unit with a rug, plastic bag, or tarp, then secure with bungee straps.

The idea is to avoid letting moisture get trapped inside the unit. Not only can mold develop, but the water can also freeze and damage the interior of the unit.

Covering your unit also keeps leaves, sticks, and other debris from collecting over the winter as well.

Finally, once you’ve covered up the AC unit use foam insulation strips to insulate any gaps between the AC unit and the window (assuming you haven’t already done this when you installed the unit). 

Tip: Do this on a warm, dry day to avoid trapping water inside the unit.

To learn more about winterizing, read these:

Air Conditioners and Winter Heating Tips: Are You Letting Cold Air In?

How to Prepare Your Furnace for Winter

Winter Maintenance Tips To Get Done Before Family Comes to Visit