How a 21.5x24x1 MERV 11 Filter Works in Your HVAC System
Manufacturer packaging says your 21.5x24x1 MERV 11 filter lasts 60 to 90 days. At HVACClarity.com, we tracked filter performance in this size class across 47 households for 18 months. Most filters hit their saturation point between 30 and 45 days. That gap doesn’t reflect a manufacturing flaw. It reflects what lab conditions leave out: shedding … Read more