If you have an air handler in your air conditioning unit, then you will probably have a vibration isolator that is designed to reduce the amount of noise produced by the blowers. These vibration isolators are usually kept in the duct, and deaden the sound produced by the AC unit. However, if they fail to work, you will quickly notice. Locating the cause of this problem is not always very easy.
Load Vibrations Occurring
This is the most common problem which occurs with air handler vibration isolators. There are a number of reasons for this problem, but the most simple one is that there is just too much noise for the isolators to cope with. These devices have to be carefully matched to the vibration they must reduce, so if there is too much noise, they will just not be effective. Change the size of your vibration isolators to correct the problem.
Noise Occurring in One Room
The air handler vibration isolators are often placed in the ducts near rooms, so if you find that you can only hear the noise from the blower in one room, this suggests that the isolators in that duct are no longer working. They may need to be cleaned, or simply replaced.