Window air conditioners are a great way to cool different areas of your home without cooling the entire house. Sometimes, however, the old girl doesn’t cool like she’s supposed to. Is she on her last leg? Well, that may be the case, but likely it’s another cause. There are many reasons that the cooling may not be all it can be.
The first problem could be that the air cooling coils are blocked and need cleaning. A buildup of crud blocks the air flow that allows the heated coils to cool. Without the proper air flow through the coils, the unit heats up and the cooling capacity decreases. Without good air flow the moisture accumulated between the cooling coils isn’t blown out of the coils and freezes up.
The second problem could be that the air conditioner could be low on freon. This causes low flow within the unit, and although the unit does cool, it is not effective cooling. You will likely hear the compressor run, but many times the compressor will cycle on and off.
The next is a common problem, especially with smaller window air conditioners. By running the the unit on low fan, the coils can freeze up. You should always run the air conditioner on medium or high fan to allow enough air flow through the coils.
As an added thing to check, make sure the drain hole is clean of debris to allow it space to drain the moisture it collects from the air.