Does your noisy air filter keep you up at night? Air filter noise is a very common problem in residential heating and air conditioning equipment, and there are many causes. Although the noise gets your attention, it may only be a symptom of a much bigger problem.
Common Causes of Noisy Air Filter
Undersized return grills and return ducts are, unfortunately, very common. They can also be the most difficult and costly problems to correct. However, there are some other solutions to this irritating problem that you may want to take a look at first.
The most common air filters used in residential heating and air conditioning systems are pleated filters, and they often don’t fit well into the return grill or air handler. Return air, like electricity and water, takes the path of least resistance and the path of least resistance is often around the air filter instead of through it.
Unfortunately, when air passes through these narrow spaces between the filter and the filter housing, it can cause whistling or even hissing noises that quickly become very annoying.
How to Fix Noisy Air Filter Problems – DIY
Here are 5 easy solutions to solve noisy air filter issues that don’t require a professional HVAC technician.
- Ensure your air filter is the proper size for the application.
This often means you have to buy custom-sized filters instead of the common sizes supplied at hardware stores, but the better the fit, the less likely it is that air will pass around the filter. - Install foam tape.
In the return grill or the filter rack, which is often difficult to Neoprene-Foam-Tapereach, you can install foam tape (gasket material) around the section where the filter sits. This helps to create a tighter fit. However, an easier alternative may be to add tape to each new air filter you install. Foam tape is available in 25-foot long rolls and two thicknesses; the thinner option is 1/4 in. thick x 3/4 in. wide. The thicker option is 1/2 in. thick x 3/4 in. wide and is best for filters that fit very loosely. - Use less efficient filters.
Pleated filters have MERV Ratings, and the higher the number is, the greater the resistance to airflow. Unfortunately, filters with lower MERV ratings won’t clean the air, as well as filters with higher ratings. - Change your filter more often.
If you only begin hearing air noises after the filter has been installed for some time, you may not be changing your filter often enough. As dirt builds up on the filter, airflow resistance increases, and this can result in the air going around the filter instead of through it. - Often when return grills are mounted in the ceiling and the filter is loose, it gets sucked up against the duct opening, causing a thud every time the fan starts. This can be corrected by building up the inner surface that the filter hits against so that the filter fits firmly into place and there is no space between the filter and the duct opening for the filter to move (as listed in number 2 above).
A better solution to fix noisy air filter problems is to install a return air filter which is designed specifically to be installed in return air grills. This is certainly not every potential problem that may cause your filters to be noisy, but these tips will help you to solve some of the most common problems you may encounter.
