When a High MERV Filter Becomes an Airflow Problem

Cool Talk with Hartzell's | Your HVAC Questions, Answered! · Sep 19, 2026 · 22m · transcript

Give Use A Shout

CO-HOST: Welcome back to Cool Talk. Dave, homeowners are trying to make their indoor air cleaner. They go buy a high MERV filter, put it in the return, and a few days later the AC is not cooling right or the coil freezes. Can a better filter actually make an AC worse? DAVE: It can if the system was not built for that filter. I want to be clear. Filtration matters. Clean air matters. But every filter is also a restriction.

I'm Dave Hartzell at Hartzell's Heat & Air in Kingfisher, Oklahoma. 47 years in the trade, Master HVAC license. On Cool Talk I cover the stuff central…