Why is my air conditioner so loud and what can I do about it?
First of all, just what is loud? A unit making a bit of noise when it starts up on the other side of the house when you live on three acres is different than a unit that is loud on startup and shuts on and off every 15 minutes under your window when you work the nightshift and are co-sleeping with your 6-month-old. There are so many reasons your air conditioner can be loud but let’s focus on the most common issues.
Usually changes in the way the ac sounds are the warning signs of repairs or replacements. but that doesn’t mean that it isn’t an easy fix – here are a few things for you to think about when your air conditioner gets loud, most of which you can do yourself with just a little time and some basic household tools.
First thing to consider is where is the noise coming from.
Is if from the fan or the compressor? Inside the house or outside? Is it loud just at startup or loud the whole time? What about the fan by the condenser coil?
If you are going to poke around in the ac first thing to do is start by turning our HVAC circuit breaker into the off position. You can do this from your main electrical panel. And turn off our air conditioner at the thermostat.
Is is the fan motor squeaking?
There are two fans in split systems. One on the inside air handler and one in the outside condensing unit. To check out the outside unit remove the outside casing so you can see the inner part of the air conditioning unit. You will see a fan right on top. Is there any debris? If so remove it while checking the unit for dings and dents. One common problem that causes noise is dirt accumulated on the fan blade. This can cause an imbalance in the fan which will then rattle and shake as it is spinning (think tennis shoes in the dryer). If your blades are bend or imbalanced then them may rub against the casing or fan cage. This will be very loud. A damaged blade will need to be replaced. Try spinning the fan by hand to see if it will spin. If it spins easily but makes a squeaky noise you can try to add some lubricant like WD-40. If the fan seems loose you can give a an adjustment with a wrench to tighten it up. If it doesn’t spin you hit the repair lottery and at the least the bearings will need to be replaced. If the sound is grinding then they will likely need replacement.
Do you hear rattling sounds from the outside unit?
While working and air condition vibrates. This vibration slowly causes screw to come loose. Loose screws are loud. The mounting screws that are holding the unit in place can also be loosened as the unit operates. Both situations will produce a rattling noise when the air conditioner is putting out air. These can all be easily fixed with a few turns of your screwdriver. Try to tighten the inside screws before the outside screws.
Do you hear rattling inside the house especially when the unit first comes on?
Examining Rattling AC Ducts – This will require you to go into the attic.
In the attic be careful not to step on the ceiling walking just on the support joists. Check all of our metal ductwork for loose fittings and screws and tighten them or tape them down with duct tape (yes that’s where duct tape comes from)
This is sometime escaping refrigerant which will require some professional service. Sometimes it is just loose ductwork.
I will have quiet!
If nothing works to quiet the system and the unit is just loud in how it operates and it is a serious issue for you than you may need to consider a new unit. With improvements in fan-blade shape and compressor technology, some models make one-twentieth the noise of old units. Could be for you.