Why Is My Window Air Conditioner Freezing Up?

Why Is My Window Air Conditioner Freezing Up

The summer heat can be unbearable, especially when you’re inside your home. It is because of this that many homeowners turn to window air conditioning units to keep their homes cool and comfortable all through the hot months. These units are fairly inexpensive and portable, which means you can place them anywhere in your home. However, like all other mechanical devices, a window air conditioner may start freezing up on you. This may seem very strange since these units are designed to get rid of heat and humidity from your home. The article below will show you some common reasons why your window AC unit might freeze.

Why Is My Window Air Conditioner Freezing Up?

Window air conditioners are great when they work properly. However, there are times when they don’t work as they should. If your air conditioner starts freezing up or you see ice on the inside of the unit, you may have a few problems that need to be addressed. Here are a few reasons why your window unit may be freezing up.

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Is The Window Air Conditioner Freezing Up?

1. Dirty Air Filter

The air filter in your window unit is there to help keep the air that is being circulated in your home nice and clean. If it gets too dirty, though, it can’t do its job properly. Clean or replace your air filter if you notice that it’s dirty.

2. Moisture Build Up In The Unit

Moisture can be a big problem for window units. It can make the entire unit freeze up and stop working properly. You can fix this by making sure all of the windows are closed when you turn on the unit and running a fan near the unit to help remove some of the moisture from the inside of it.

3. Window Not Properly Sealed

When your window unit doesn’t get enough cool air from outside, it will have to work harder to keep up with cooling off your home. If your windows aren’t sealed properly around the unit, this could cause excessive wear on them and lead to more problems down the line. Make sure that you check around each of the windows where they meet up with the frame each season before you turn on your AC for proper sealing.

4. Low Refrigerant Level

Your air conditioner uses a refrigerant called “Freon” to cool off your home or office while using as little energy as possible during operation. If this level gets too low, though, you may end up with problems such as freezing issues. Make sure that you keep an eye on your Freon level to make sure it’s not too low. If it is, you may need to have someone come out and charge your unit.

5. Dirty Coils

The coils that are a part of the air conditioner are what help the unit cool off your home or office. If they get dirty or clogged, though, they can’t do their job properly and your unit may freeze up as a result. Cleaning them out regularly can help prevent this from happening.

6. Blocked Exhaust System

If you notice that there is ice around the exhaust system on your window air conditioner, it could be because the system is blocked by debris or other items around it. Make sure that you check this area out to see if there are any problems with the exhaust system so that you can fix them and prevent further issues from occurring.

7 . Low Ambient Temperature

If the temperature outside is below freezing, your window AC may have trouble keeping up with cooling down your house or office because of low ambient temperature conditions. You should turn off your AC until temperatures outside rise above freezing to avoid any issues with this occurring again in the future. 

8 . Dirty Evaporator Coils

Dirty evaporator coils can cause an air conditioning unit to not cool properly and may lead to other issues as well. When the coils are dirty, they can’t effectively cool your home or office. The refrigerant in the coil won’t be able to do what it is supposed to do, and you will have problems with temperature control. Cleaning out the coils can help avoid this problem from occurring in the future.

9 . Duct Leaks

If you have leaky ducts in your home or office, it could be causing too much or too little airflow in different parts of your home or office. This can lead to issues with your AC unit as well since it will have to work harder when there isn’t enough airflow throughout your home or office. Make sure that you check all of your ducts for leaks and seal them up if you find any to avoid issues with your AC down the line.

10 . Ac Unit In An Unusual Location

If an air conditioner is located in an unusual spot like near a window that opens often, it may not cool properly due to hot drafts coming into the room from outside. While placing an air conditioning unit next to a window isn’t always possible, if it is necessary then make sure that you install some type of insulation around the area where the window meets up with its frame so that there aren’t many drafts coming into your room from outside during operation of the AC unit.

Your A/C May Be Too Old

  • If your unit is more than 10 years old, then it could be time to replace it. Even if your unit is still running well, it’s probably best to upgrade to a more efficient model.
  • If you’re using a window air conditioner in a room that’s too large, then your unit could be overworked and freeze up. The larger the room, the larger the AC unit necessary to keep it cool.
  • If you have very hot or humid temperatures outside, then you should upgrade your AC unit or install a whole-house system instead of relying on window units.
  • If you live in an area that has extreme winters or summers, then you should consider getting a whole-house system instead of relying on window air conditioners for heating and cooling.
  • If you live in a place where the temperature fluctuates wildly, then you should consider a whole-house system instead of using individual window units. A whole-house system will keep your rooms cool during the summer and warm during the winter.


If your window AC unit is freezing, then there is a problem with cooling your home. You should check the evaporator coils, the condenser fan, and the filters before replacing your unit. Also, make sure your unit is not too old. If none of the above applies to you, then you should get your unit looked at by a professional.