Winterize Your AC Unit in 6 Easy Steps

Margaret Wack
Written by Margaret Wack
Updated November 23, 2021
Window air conditioning on a brick building
James –

Winter is coming!

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As autumn rolls around and the temperature begins to plummet, it's time to think about winterizing your window air conditioning unit. Properly preparing your AC for winter storage will help lengthen its life and ensure it stays in working order for the summer. Luckily, you can winterize your AC with just a few simple steps.

Difficulty: 1/5 You've got this!

Time: 1 hour

Tools and Materials Needed:

  • Towel

  • Screwdriver

  • New filter

1. Turn the AC Off

The first step is to turn your AC off. You’ll want to do this before you remove and clean the unit.

2. Remove the Unit

Because the appliance tends to be pretty big and heavy, removing an air conditioning unit is typically a two-person job. Be extra careful during this step to avoid dropping the air conditioner. 

First, unplug the unit and remove the front cover. Then, take off any insulation surrounding it. Finally, lift the unit out of the window and place it on a towel. Know that your air conditioner may leak slightly—this is normal and nothing to worry about.

3. Remove the Base

If applicable, remove the base of the air conditioner. Use a screwdriver to carefully remove the base from your windowsill.

4. Clean or Replace the Filter

Woman removing air conditioner filter with screwdriver
auremar –

After working hard to keep you cool all summer, your air conditioner’s filter is most likely a little worse for wear. Most AC filters should be removed and either cleaned or replaced on an annual basis to improve energy efficiency. In fact, cleaning or replacing your filter can improve efficiency by 5% to 15%, according to the United States Department of Energy

If you’re replacing your filter, go ahead and insert the new filter into the unit now, so you won’t have to in the summer. If you have a reusable filter, rinse it under running water and allow it to soak for a deep clean. Then, wipe down the AC coils and the outside of the unit with a wet rag.

5. Conduct Any Necessary Maintenance

The end of the season is a good time to conduct any necessary routine maintenance on your air conditioning unit. If your air conditioner has been experiencing any issues, get in touch with an HVAC professional near you. They can help you repair your unit and get it ready for the following summer. A professional can even help you decide if it's worth making repairs on your unit or replacing it altogether.

6. Store the Unit

You’ll need to store your air conditioner for the season until temperatures climb again. Store the unit in a cool, dry place and cover it in order to prevent it from getting dusty. Make sure that your air conditioner is elevated off the ground if you store it in the garage, and protected from pests if you store it in the attic.

Is it Okay to Leave an Air Conditioner in the Window During Winter?

It can be tempting to leave your air conditioning unit in your window throughout the winter, but it’s not a good idea. Removing your air conditioner and safely storing it is the best way to protect it from bad weather. It will also help to ensure that your room is air-tight and doesn’t let any cold air in.

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