Will a 21.5x26x1 MERV 11 Filter Restrict Airflow in Older Systems?
Filter MERV rating is one of the first compatibility checks I run on any VentOwl inspection — especially in Florida homes with systems that predate the variable-speed blower era. The question I hear most is some version of this: “I want better air filtration, but I don’t want to damage my system.” When that question … Read more