18x20x2 Aerostar Air Filter

A nominal 18x20x2 return takes a filter measuring 17 1/2" x 19 1/2" x 1 3/4" actual, which is what this Aerostar is built to. Two-inch filters in this size were common spec on older residential furnaces and remain widely used in light commercial systems. The 2-inch depth holds roughly twice the debris of a 1-inch equivalent and runs at noticeably lower static pressure. MERV 8 is the baseline residential choice: dust, lint, pollen, no significant allergen load. MERV 11 covers pet households and most common allergy concerns. MERV 13 captures fine particulates - smoke, bacteria, virus carriers. The pleated electrostatic media is manufactured by Con-Air Industries in Orlando, Florida. The electrostatic charge built into the synthetic fibers catches particles smaller than the weave would stop on its own. Cardboard frame, reinforced to hold shape under blower suction. Plan on a 4-to-6-month change interval for MERV 8 and 11 in typical residential use, 2 to 4 months for MERV 13 under similar conditions. The 2-inch depth is what makes this filter outlast cheaper 1-inch alternatives - more media in the filter equals more capacity before pressure drop becomes the limit.