How to seal a window air conditioner for the winter?

Do you have a window air conditioner in your home? If so, what are you going to do with it when the temperature drops below freezing? Sealing your window unit will protect it from moisture and dust so that you don’t have any leaks, cold air seeping inside, or potential condensation problems over the next few winter months. Here are some recommendations on how to seal a window air conditioner for the winter right.

How to seal a window air conditioner for the winter?

In the hot summer months, an AC unit can come in handy when every day lasts forever and temperatures soar. But during wintertime, your air conditioner will have a tough time fighting off harsh cold weather outside that may damage it. To keep your air conditioning unit healthy all year long through any type of season or weather conditions, it is very important to properly care of your window air conditioner, especially during the winter season.

Winterizing Steps

Before winter sets in and temperatures drop, you’ll want to prepare your air conditioning unit for the cold temperatures ahead. If you take a few steps now before it gets too chilly, your window ac unit will continue working well into future summers without any problems.

Step 1 – Switch the Air Conditioner Off

The best way to stop your air conditioner from freezing during the winter is by turning it off. You should open the control panel and turn off your AC unit to avoid it turning on during an unseasonably warm day. If you want to stop your AC from turning on, double-check that it is in the “off” position. And remember to turn it back on when summer comes around so as not to waste time wondering why the window ac unit isn’t working!

Step 2 – Cleaning the AC Unit

The first step in cleaning your air conditioner is to thoroughly wash it with water and dish soap. After rinsing, let the unit dry completely before repeating steps one through three. Make sure not to use a pressure washer because this can damage its components.

Use a hose or large spray bottle filled with plain water in order to completely clean its surface from dirt and debris that has accumulated over time while being exposed the sun’s UV rays outdoors. Once everything is washed away take some time for this part outside of the house as well if possible because there will be no residual odors remaining after rinsing off all traces of dish soap used during this process which should help minimize unwanted scents inside.

Step 3 – Clean your air conditioner While It’s Off Season

While it’s turned off for the season, take this opportunity to clean your air conditioner. Dust and lint have a way of collecting on window units so they should be cleaned periodically. Remove the front grille from the unit by pressing down firmly with something flat as you pull outwards; if that doesn’t work use a putty knife or even better yet, just yank towards yourself until it comes loose (this one will require some more elbow grease). Once removed find soap warm water along with scrub brush can help get stubborn dirt particles up before using vacuum cleaner attachment to finish cleaning surfaces thoroughly.

Step 4 – Insulate Exterior Parts

The final step before placing the unit back into its window frame is to insulate exterior parts of your window ac unit.

Because the appliance is placed in a window frame, there might be unwanted open spaces wherein the chilly winter breeze may come striking at you without notice. For this step, we hope that you’ve prepared even just a bit of money to purchase foam insulation.

Once you have purchased foam insulation, prepare to measure the width and length of the areas where they need to fit, then cut foam strip according to your measurements, and put them inside gaps between the window’s frame & ACs body as well ensure that it stays tight so no outside air enters from outside!

If temperatures drop particularly low, you may consider double-insulating instead, since this will protect both from heat loss and extreme weather conditions which can freeze up the machine itself causing serious damage.

Step 5. Cover the Entire Window AC Unit

Next, cover the entire air conditioner unit with plastic or vinyl and secure it using duct tape. Take extra care around the perimeter of your cover to ensure that it is waterproof because this step will protect both you and your home’s window ac unit from many types of damage including water leaks.

One way is to create a DIY cover for your window unit. You may find some nice AC cover DIY videos on Youtube. Another option is to find a fitting cover in local hardware stores or Amazon.

This type of insulation works double duty as well since throwing on a layer over cold winter days also protect against chilly breezes coming through windows where these units are installed.

Step 6 – Maintain your air conditioner

One of the best ways to make sure you’re taking care of your AC unit is by performing a weekly physical inspection. When it’s cold outside, be particularly careful removing snow and ice and making sure there are no twigs on or around the exterior units that could damage them if they fall off in harsh weather conditions. If you find any loose elements during these inspections don’t hesitate to take them off completely in order to inspect what might be causing problems underneath as well! Lastly, once everything has been taken care of, properly put all parts back where they belong so nothing gets damaged when winter rolls around again.


If you’re looking for ways to protect your AC unit from the upcoming winter, read on. The article gives a number of tips that will help keep your air conditioner clean and working next summer! Have you properly insulated your window AC for winter already?

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