Derek Cole explains why high-MERV filters can backfire in tight, energy-efficient homes by restricting airflow and getting sucked into the return grille. Cheap filters only catch large debris and miss the small invisible particles that matter. Match filter efficiency to your home's duct tightness.
Chapters
Your system will determine what filter it can handle. So if you have a tight home, a newer home, and it's a tight construction, energy efficient construction, and your duct system is tight, then putting a really high MERV rated filter in that system could cause more problems than good. So you could put in a filter that stops up the airflow, which is a problem. On the other side of the spectrum is a cheaper filter or a cheap filter, 80 cent dollar filter you put in there. And it's not very good at all because, you know, only thing is stopping is sandwich bags and, and Coke cans. Anything else you throw at it. Yeah, it's 100% efficient at stopping that. But 98% of what we're trying to stop are the particles you cannot see. So if you look at your TV or your cabinet and you see dust on it, we're not trying to filter that because it's so heavy it's sitting there. You're trying to filter the particles in the air that are coming through and those you cannot see. So you need a better filter for that. Once you get into air cleaning, then you actually stop filtration and go into air cleaning. And the reason you want to do that is because now you're getting the small particles you cannot see and you're not stopping up your duct system. So if you go to the filter on the return grille and it's too tight and the filter is getting sucked in, then the filter is too much for that system to handle. So you need to go down in filters.
