All furnaces come with the recommendation to change the filter at least once a month. We don't know about you, but it's really hard to remember that one small task. Maybe if we had a stock of filters nearby it would be easier and that's where Home Depot comes in handy. Today only, save 45% off select Honeywell air filters, with prices coming in at $22.99 each. These filters come an array of sizes are all rated Allergen Plus. Offer valid only on 10/15/2015.