HVAC & furnace filters in every standard size

For most residential HVAC systems, MERV 8 is the everyday standard — strong airflow, captures mold spores, dust mites, pet dander, and pollen. Upgrade to MERV 10 or MERV 11 if you have pets, allergies, or want finer particle capture. MERV 13 is the top residential tier — excellent for smoke and fine allergens, but verify your system can handle the extra airflow resistance first. For older systems, stick with MERV 8 or lower unless your HVAC installer confirms a higher rating is safe.

It depends on depth and environment. A 1″ pleated filter typically lasts 1–3 months in a residential system. A 2″ pleated filter lasts 3–6 months. 4″ media filters in a dedicated cabinet can last 6–12 months. Homes with pets, wildfire smoke exposure, construction dust, or high occupancy should replace more frequently. The honest answer is never a single number — check your filter monthly and replace when it looks loaded.

Yes. We build custom filters to 1/8″ in both width and height — any depth from 1″ to 6″, any MERV from 1 to 13. Use our Custom Filter Builder to configure the exact size, depth, and MERV rating you need. Custom filters ship as a case (case count varies by depth) and are produced to PrimeShield specifications by our partner manufacturers.

Standard in-stock filters ship from the closest stocked location, typically arriving in 2–5 business days within the lower 48. Custom filters have a production lead time before shipping — see our production schedule for current timing. Free shipping on orders $50+ to the lower 48. We do not ship to PO boxes (filter boxes are oversized). UPS and FedEx are our primary carriers.

Yes — commercial accounts are a core part of what we do. We offer commercial filtration programs with dedicated account support, volume pricing, Purchase Order terms, tax-exempt purchasing, and filter-size tracking for multi-property portfolios. Request a quote for your specific facility or fleet and we'll build a program around your actual filter list and replacement schedule.

Our Filter Fit Guarantee™ covers you for 30 days. If the filter doesn't fit your equipment, we'll make it right — either by resizing a replacement, swapping to a different size, or refunding the order. The guarantee is one of the only ones like it in the industry.

Yes. Our Price Beat Guarantee covers identical filters from competing retailers — same brand, same MERV, same size, in-stock and shipping from a US address. Submit the competing listing and we'll verify and beat the price. We don't match overseas-sourced knockoffs or third-party marketplace sellers whose inventory can't be verified.

Our trusted manufacturer lineup includes AAF Flanders, Koch, NaturalAire, PrimeShield (our own line, treated as a peer brand), VariCel, DriPak, and others. We focus on filters made by established filtration manufacturers — no overseas knockoffs, no anonymous private labels. See the full brand lineup or shop by brand from the top navigation.

The size is printed on the cardboard frame of your current filter — typically something like 16x25x1 or 20x20x4. That's the nominal size (width × height × depth). If your filter doesn't have a size printed, or if it's a non-standard cavity, see our how to measure guide. Actual filter dimensions are usually 1/4″–3/8″ smaller than nominal so the filter slides freely.

Standard returns are accepted within 30 days. Filters must be unopened and in resalable condition. Custom-built filters (Exact Filters® and custom-size builds) are non-returnable because they're produced to your specifications — but the Filter Fit Guarantee™ covers fit issues for 30 days. See our full return policy for details.