MERV Rated Replacement Air Filter: AIRx Filters 20x25x4 (Actual: 19.38 x 24.38 x 3.63 in) MERV 11 air filter assures the effectiveness of your home HVAC system resulting to efficient heating ...

That’s one reason why you need furnace filters, and there’s another. Filters purify the air coming from the furnace so you don’t have to inhale microscopic dust particles and other contaminants. In ...