Keeping a Window Air Conditioner From Freezing Up

An air conditioner unit in a window.
What You'll Need
Air Compressor
Soap and water

In the summer months, an air conditioner sitting in your window can make life a little more bearable. But as great as these types of units are, they do not come without their own set of problems.

Aside from running up your electric bill in the summer, a window air conditioner has also been known to form ice on the vents or freeze up altogether. Some people will attribute this problem to having too much refrigerant in the air conditioner, or to running it continuously. Here are a few reasons why your window air conditioner might freeze up and what you can do to remedy the situation.

Step 1 — Purchase the Right Size Air Conditioner

One of the most common problems associated with window air conditioners freezing up is that they are either not big enough for the room, or are too big for the room. Either extreme sizing issue will cause ice to form on the vents. A unit that is too small will have to run much harder than it should in order to keep a large room cooled down. This will result in a lot of condensation forming and resulting in ice.

On the other side of that, an air conditioner that is too large will eventually form ice on the vents because it does not run enough. Condensation from sitting in the sun will form on the coils and condenser. When purchasing your window air conditioner, make sure it is the right size for the room it will be cooling to prevent it from freezing up.

Step 2 Check Filter and Change

A routine check of the air filter in the unit will help to prevent you from having any issues. A clogged or dirty filter can cause it to malfunction by not getting an adequate flow of air. Keep the filter clean by removing it and cleaning it with a vacuum, air compressor, or soap and water.

This should be done every couple of weeks during the middle of summer, or when there is an abundance of dust or pollen.

Step 3 Clean Cooling Coil

During the use of the window air conditioner you might seem some condensation forming on the cooling coil. If it begins to turn to freeze up, it means that it needs to be cleaned out. This is a job for a professional cleaner because it needs to be flushed out, but you should always keep your eye on this.

This should be cleaned regularly, every one to two years.

Step 4 Do Not Run in Cold Temperatures

When the temperatures outside begin to drop, even during the nighttime, this will cause the temperature in the cooling coil to also drop. This coupled with the rising moisture and heat from the house will cause the unit to freeze up. Once the evenings begin to cool off, and the daytime temperatures are comfortable, you should remove the unit from your window so it does not cause frost and ruin it.

Follow these tips and you are sure to keep your window air conditioning unit from freezing up!