Window air conditioners should remove humidity from your space if they are working correctly and should not be increasing humidity levels in your space.
Window air conditioners take the hot air from your space and cool this air down, but they also extract humidity in the process.
If your window air conditioner is not removing humidity, but actually increasing it, there is something wrong with the size, the humidity in your space, or with the other components within the unit.
How window air conditioners cool down your space
Air conditioners do much more than lower the temperature of your room. Window air conditioning units work by taking in the hot air from your room and running it over a series of coils with refrigerant, which is warmed and cooled by a compressor in order to remove heat and moisture from this air.
In a window unit, excess moisture, which collects around the coils as the air is cooled down, drips into a drip pan and drains out of the back of the unit to the outside of your house.
Do window air conditioners cause humidity?
As a result of this process, all air conditioners, including window units, have a dual function, which is to remove the heat from the air and to extract moisture from the air.
This means that if your air conditioner is working correctly, it will make your room less humid, by removing humidity from the air as it is cooled down.
High humidity levels can be quite uncomfortable to live in and they are actually the perfect breeding ground for the growth of mould and other bacteria, which can end up being dangerous for your household.
For this reason, it is important that you use a hygrometer to determine whether the humidity in your home is increasing when you turn on your air conditioner, or whether it just feels like it is. If the humidity is increasing, then there are a few different reasons why this may be happening.
The most common reason why window air conditioners would be increasing humidity levels in a space is because the unit is too big for the space that it is in.
The second most common reason is that the humidity in your area is a lot to begin with, and your air conditioner cannot keep up.
Increasing humidity levels may also indicate that there is an issue with one of the components in your window air conditioner and it is not functioning properly.
Why an oversized window air conditioner can cause humidity
One of the vital factors to consider when you are buying an air conditioner is to choose an air conditioner that is the right size for the space.
Experts recommend that your air conditioner should have about 20 BTU for every square feet of space, but there are other factors that determine whether you need to size up or down when you are choosing a window air conditioner.
Although the BTU-to-room-size ratio is not precise, an air conditioner that is wholly too large will cool your room too quickly, which will cause it to short cycle.
When this happens, your air conditioner cannot run a complete cycle and the humidity will not be removed from the air in your room.
However, if you already have the oversized unit installed, a good way to combat the higher humidity is to install a dehumidifier in your home, like this Frigidaire dehumidifier, which is specifically designed for spaces with high humidity levels.
Why your window air conditioner is struggling if you live in a high humidity area
Although air conditioners have this dual dehumidifying and cooling function, if the humidity in your area is very high to begin with, your air conditioner may be struggling to keep up and this could be why it is not removing the humidity from your space effectively.
In this case it is best to try and eliminate as much humidity as possible from the inside of your home by installing vents in high-humidity areas like the kitchen and bathroom.
Which issues in your air conditioner could be causing humidity?
When your air conditioner is not dehumidifying your space optimally, this is most likely due to an issue with the unit’s compressor or with the drainage system. A blockage in the drain line or overflow of the drain pan will mean that moisture can be blown back into your space by the fans.