Add four of these HDX Furnace Air Filters to your cart and drop to 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 HDX FPR 10 premium pleated furnace air filter. Other sizes are available at the same price. Additional filter types are on sale for more when you purchase four. We are still in the middle of one of the hottest summers on record. If you’re not changing your air filter regularly this could lead to problems. The lack of air flow and cold air are just a couple of signs you may need repairs soon. Take advantage of this deal from Home Depot now.