All too often, homeowners write off their noisy air conditioners as just being "old." Indeed, older air conditioners are more likely to become noisy than new ones in pristine condition, but the noise your AC unit is making is not an issue you should ignore. Noises mean something is wrong with your AC unit, and they usually mean it needs one or more of the following repairs.
Ball Bearing Replacement
The fan associated with your AC unit has a lot of moving parts. There are ball bearings between those parts to allow them to slide over one another more easily. If one of those ball bearings becomes worn down, then there will be more friction between the ball bearing and the parts on either side of it. This will often lead to a grinding or scraping noise, which will be most obvious when the fan is starting and stopping. An HVAC repair contractor can replace worn ball bearings fairly easily. Each ball bearing should only cost a few dollars, and the labor to install them is not much.
New Fan Belt
The motor that drives your AC fan has a belt that goes around and around. This belt suffers a lot of wear and tear over the years, and eventually it may start to fray. The frayed part of the belt may make a whirring noise as the AC unit operates. Or sometimes, you'll notice that your air conditioner squeaks or squeals. The easiest way to solve this problem is simply to replace the fan belt. This may take your HVAC contractor a few hours as there are a lot of bolts and screws for them to undo and redo, but it's not that complicated for an expert.
Leak Repair
If the noise could be described as buzzing or humming, then you may be dealing with a refrigerant leak. When an AC unit leaks refrigerant, the remaining refrigerant expands too much, which means it gets colder than it should. The buzzing noise may be frozen parts struggling to move. You may also hear some crackling as the metal components freeze and thaw. An AC contractor can locate and repair the leak. Then, they can top your unit off with some more refrigerant.
If your AC is noisy, it's probably not just because it is old. Contact an HVAC company in your area, and have them come take a look, as they are equipped to deal with ac repair.
