Heating & Cooling

Storing A Window AC Outside In Winter: We Ask The Pros

midea window ac

After the hotter summer months start to come to a close, it might be time to start cleaning and storing your window units. But there are a few questions you might have. 

These questions might be, “Where should I store my window unit?” or “Can I store my window unit outside during winter?”

Storing your window air conditioning unit is a vital part of its longevity. With that said, keeping your window unit outside or in cold areas can make the coils freeze over. If the window unit’s coils freeze over, it can cause your window unit to no longer work. 

To properly store your window air conditioner, you should fully clean the device. 

Once your window unit is spotless, you can wrap it in a sheet or a blanket to prevent dust build-up over the coming months. Storing your window unit in an ideal environment away from cold or moist areas. A perfect place is a closet or even your attic.

As you continue to read this article, it will provide you with the necessary steps you should follow when you want to store your window unit. 

Can I Store My Window AC Unit Outside During Winter?

If you are looking to safely store your window air conditioning unit, the last place you should keep it is outside. Storing your window unit outside will leave it fully exposed to the elements. As previously stated, leaving your window unit out during the winter months can lead to irreparable damage.

For example, suppose your coils freeze over and are left frozen for an extended period. In that case, it will severely damage your window unit’s coils and the compressor. 

Furthermore, other things can happen that will be out of your control. For example, animals might rub up against or hit your unit’s fins. 

Damaging the fins will decrease the air your unit can take in and thus reduce its cooling effectiveness.

How To Properly Store My Window Unit During The Winter Months

When it comes to storing your window unit, there are a few things you will need to do. You will first need to clean your device thoroughly. Cleaning your window unit before storage will increase its overall lifespan.

Once your window unit is spotless, you should wrap it in a heavy blanket or plastic. Covering the window unit in a blanket will protect the device from being damaged while it is not in use. 

In addition, the blanket will prevent dust build-up and can even prevent some damage from stuff falling on your window unit.

When you have wrapped your window unit in a blanket, you need to store it. The area in which you hold your window unit is significant. Try to find a dry and preferably a dry place as well.

How To Clean A Window Air Conditioner

Cleaning your window unit is possibly an essential step you will need to take when you want to store it. Cleaning your window air conditioner has many different benefits. 

  • Firstly, a clean air conditioner will use less energy to cool air than a dirty one. 
  • Secondly, cleaning your air conditioner regularly and before storage will prevent mold and mildew from growing on your device. 
  • Lastly, keeping your window unit clean will give it a longer life span.

The process you will need to take to clean your unit is not very complicated. However, if it is your first time doing so, it might take some time to clean it thoroughly. 

Below we will discuss the tools and steps you need to take to clean your window unit.

The tools you will need to have on hand while cleaning your window unit are as followed:

  • Lots of warm water
  • Reusable washcloth or dish towel
  • Dish soap
  • A spray bottle filled with 3% hydrogen peroxide
  • A soft-bristle brush
  • Some compressed air
  • A vacuum cleaner
  • A screwdriver
window ac air filter lg

1. Cleaning Your Window Units Air Filter

Cleaning the air filter on your window unit is the most crucial step. It is recommended to clean your filter on your window unit monthly, even if you do not plan to clean the entire device. 

The first thing you will need to do is unplug the appliance and remove it from the window. 

Once it is safely on the floor, unscrew and remove the unit’s faceplate. After you have successfully removed the faceplate, take out the air filter. Then you will need to vacuum as much of the dust and hair as you possibly can. 

After cleaning the filter, please take it to your sink and gently wash it with warm water and dish soap.

Leave the filter to dry completely before returning it to your air conditioner. If you are cleaning the entire device, leave it to dry and place it back in after cleaning the rest of the unit.

window ac grill lg

2. Clean The Grill And The Exterior Of Your Window Unit

The next step is to wash the grills and the outside of your window unit. The best way to do this is to wash it with warm water with a bit of dish soap. 

After cleaning it with soap and water, use a damp washcloth to wipe away the soap. 

If you do not want to use soap, you can use a damp washcloth and wipe away any dirt and grime on your window unit. Be sure to get into the crevices of your unit where dust and grime can build up easier.

Once you have sufficiently cleaned the outside of your device, allow it to sit and fully dry before you continue.

dust coils lg

3. Clean The Dust Off Of The Fins And Coils

Once you have cleaned the outside of your window unit, it is time to start cleaning the inside. Start by cleaning the dust off of the fins. Next, get your soft bristle brush and softly brush and scrape the dust build-up on the fins inside the window unit. 

You must be careful during this step because the fins are flimsy and sharp. If you accidentally bend a few fins, try your best to softly turn them back into place. 

Leave them be if you feel like you are unable to. You have to be careful with the fins because that is where the air comes into your window unit. 

If any of the fins bend, it reduces the amount of airflow. It thus reduces the overall cooling effectiveness of your window unit.

You do not need to clean the coils whenever you want to thoroughly clean your window unit. However, manufacturers recommend that you do this step at least once every four to six months to prolong the unit’s life.

Once you have brushed the fins, take the same brush and thoroughly brush the coils to remove dust and dirt build-up. After successfully brushing off both of these parts, spray the inside of your window unit with condensed air. 

This will help remove all of the dust that you just cleaned off. Do this step and be as thorough as possible. Any leftover debris can make your device not work when you plug it back in.

drip tray lg

4. Clean The Drip Tray And Water Drainage Tubes

Now it is time to finish cleaning the inside of your window unit. Take the drip trap and wash it in your sink with hot water and dish soap. Cleaning the drip tray will rid any possible mold or mildew that might have grown in it. Leave the tray out to dry. 

Next, you will need to check the drainage tubes inside your window unit. See if anything is clogging the pipe. If there is, using a wet/dry vacuum will most likely clear the tube. 

If you do not have one, using a flexible wire bent with a hook at the end will do you justice. Just be sure not to damage the drainage tubes while unclogging them. 

After checking or unplugging the drain tube, wipe the tube’s opening to ensure a clean and clear path for the water to come out.

window ac lg

5. Time To Reassemble Your Window Unit

After you have completed every step and everything that needs to dry is dried, you will need to put everything back together. Start by reattaching the drip tray. 

You can then re-dust the device’s inside with more compressed air if you want to. Now, reattach the air filter and faceplate.

After everything is back together and clean, take your bottle of peroxide. You will spray the areas where air flows in and out of your window unit. This will sanitize those areas and provide you with cleaner air.

Storing Your Window Unit After Cleaning

Once you have thoroughly cleaned your window air conditioner, it is time to wrap it up and safely store it away. Take a heavy blanket and wrap your unit. You can also put it in a heavy-duty garbage bag and place it in a box for safekeeping. 

Wrapping your window unit in a blanket or putting it in a bag and box will prevent dust build-up and potential damage from other objects falling on it. 

After you have wrapped it in its safety blanket, all you will need to do is store it. Of course, the ideal area where you will want to store it is in a dry and preferably warm area.

A perfect example of this is in a closet or a dry attic. Either of these is an excellent place to store your window unit.

Final Thoughts

Storing your window unit correctly is integral if you want to use it for as long as possible. With that said, cleaning it beforehand will also help prevent damage. 

You should store your window air conditioning unit in a warm, dry area inside your home. Storing it outside can leave it exposed to animals and the outside elements. Both of which can end up causing irreparable damage.


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.