Recently, a reader had a question about their home air filter:
Good day. I’ve been using the Dupont Filtrete filters for about five years and since we run a landscaping business and track alot of dirt in with us at the end of the day, I change out our filters about every three weeks. Within the past couple of years though, I’ve noticed that the metal mesh within the filter makes a flexing noise similar to water dropping for the first couple seconds after the condenser shuts off. It doesn’t make the noise when first installed and also when the a/c is not run for long periods of time, like during the middle of the day. Definitely nothing is leaking and even a Trane representative verified that the noise is made by the filter. Could you recommend a good filter that either doesn’t have the metal mesh or one that is sufficient in thickness that it doesn’t flex enough to allow this noise to occur? Thank you for your time and help.
I’ve chosen to answer the question in a post, as this may require a bit more explanation than a comment can handle.
Now, for the more complicated part. This air filter should not be “sucked up” into the AC unit, as described by this commenter. Additionally, a filter without the metal mesh will only be more flimsy and may even be sucked up into the coils of the unit.
So, what’s the solution?
Well, I’ve had a similar issue with an AC unit that would crumple the air filter. I later determined that the unit used a custom-sized air filter that you could only get from the AC manufacturer. It had strange dimensions that made store-bought filters not fit, properly. This could be the issue, here.
It could also be an issue with a necessary pre-filter, post-filter, humidifier, or other component that needs to be in place. I would think the Trane representative would have mentioned this in the visit, but they miss stuff, too.
Regardless, the AC unit should not be sucking-up or otherwise deforming the filter. I would call out your local HVAC professional to take a look at the unit and filter to determine the proper solution for that unit, after confirming that you have the right size air filter. Every unit is different and even HVAC companies specialize or represent specific brands, so make sure it’s a Trane endorsed contractor.