20x36x1 Aerostar Air Filter

At 19 3/4" x 35 3/4" x 3/4" actual, the 20x36x1 Aerostar fits a nominal 20x36x1 return. Long-rectangle returns in this size show up on larger residential air handlers and some commercial applications. Three MERV grades cover the standard residential range. MERV 8 for baseline household dust and pollen filtration - the standard choice without pets or specific allergy concerns. MERV 11 for pet households, smoke residue, and most common allergens. MERV 13 for fine particulate capture including bacteria, virus carriers, and wildfire smoke - recommended for households with respiratory health issues. Pleated synthetic electrostatic media construction. The pleats give you substantially more surface area than a flat fiberglass filter at the same nominal size, which is why this filter outlasts cheaper alternatives even at higher MERV grades. The electrostatic charge built into the fibers improves capture in the sub-micron range, where the physical weave alone reaches its filtration limits. Manufactured by Con-Air Industries in Orlando, Florida. Cardboard frame, reinforced to hold shape under blower suction - frame collapse is a common failure mode in cheaper filters and allows unfiltered air to bypass the media entirely. Plan on 60 to 90 days between changes for MERV 8 and 11, closer to 30 to 60 days for MERV 13.