The lead offer at Air Filters Delivered is the up to 40% off sale on 1 inch air filters, and it is best for shoppers who need standard 1 inch filters and want the largest single item discount on selected stock. The 40% deal applies to selected 1 inch products on the website while stock lasts, so it is the place to start if those exact filters match what you need.
If your order is under $65 (small purchase), pick the specific sale that covers the item you want. For example, if you need a 1 inch filter that is part of the up to 40% off sale, that sale will usually save more than the first order 8% option. If the item you want is a Trion Air Bear or Lennox model on sale, use the up to 20% off Trion or Lennox sale instead. If you are a new customer and the filter you want is not in any of the sale ranges, the up to 8% off your first order may be the better fallback for the same small order.
If your order is $65 or more (to get free shipping), factor in the free shipping on orders over $65. For example, a $100 purchase of a selected 1 inch filter at 40% off becomes $60 before tax, and you also qualify for free shipping. If the item is a Trion Air Bear or Lennox model on the up to 20% off sale, 20% off a $100 item gives $80 before tax; the 40% sale on an eligible 1 inch item still leaves you better off at $60.
If you want a subscription for ongoing deliveries, the subscription discount of up to 8% applies to subscriber orders and runs to October 31, 2026. Use that when you are setting up a recurring order for filters that are not covered by the bigger one time sale. If a filter is in the 40% sale and you can subscribe to it, compare the one time 40% price with the subscriber price to decide which gives the lower total over the period you plan to buy.
If you are buying a specific brand model such as Trion Air Bear or Lennox, use those up to 20% off sales when they apply, because those sales only cover those brand models and may beat a first order 8% saving on the same item.
Our records show the 40% sale is large compared with the typical percentage code of 15% in the 12 months to October 2026, but smaller than the biggest percentage sale recorded in that period, which reached up to 63% off. Our team carried out 26 checkout tests across 26 offers in the 12 months to October 2026.
To choose between the options that apply to your basket, work out the final price on the item: start from the original price, apply the sale percentage you are offered and compare the totals including whether you cross the $65 free shipping threshold. Take whichever option leaves the lower total. If an offer specifically says it applies to subscribers only, use that only when you are signing up to a subscription.