4 Furnace Air Filters from $28

Add four of these HDX Furnace Air Filters to your cart and drop to as low as low as $27.96 total at HomeDepot.com. Plus shipping is free. That's as low as $6.99 shipped per filter, which is the lowest shipped price we found. Choose from several types and sizes, including the pictured Allergen Plus Pleated Furnace Air Filter (FPR 7, MERV 11) in size 20" x 20" x 1". Other sizes are available at the same price. Additional filter types are on sale for more when you purchase four.