2021 test14 productsHome Appliances
Which HVAC Furnace Filter Brand Wins?
A head-to-head test of 14 hvac furnace filter options with the measured results for each. See how they ranked and watch the full test video.
Ranked first
AAF Flanders Easy Flow (no MERV rating, fiberglass)
Price shown in test: $1.08
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The measured results
Every number below is read straight from the test. Scroll sideways to see all measurements. Products are listed in the order they finished.
| Product | Rating/lifespan | Clean filter static pressure | Dirty filter test (1 cup flour) | Media analysis |
|---|---|---|---|---|
| 1AAF Flanders Easy Flow (no MERV rating, fiberglass)$1.08 | no MERV rating, fiberglass media, claims to stop up to 4 times more dust than competitors, lasts 30 days, made in North Carolina, high air flow design | baseline with no filter was 0.16 in of water column; Easy Flow added only 0.08 for a total of 0.24, an impressively low result | small particle count over 22,000, large particle count over 20,000 (worst filtering result of all filters tested), static pressure recorded as '26' (kept verbatim; almost certainly a garbled '0.26' given every other static pressure figure in this video is on a 0-2 in-of-water-column scale, not corrected) | not tested |
| 23M Filtrete Basic$4.97 | no explicit MERV number given; described as a very basic filter designed to stop lint and household dust only, explicitly not designed to stop dust mite debris, mold spores, or pollen; lasts up to 90 days, made in Mexico, 14 layers of filter media | added 0.27 over the 0.16 no-filter baseline for a total of 0.43, described as very restrictive and not good | small particle count 1,400, large particle count 1,100 (much better filtering than Easy Flow), static pressure 0.87, described as very high and likely to cause blower motor damage over time | not tested |
| 3Air Care Indoor Air Quality Specialists washable electrostatic filter$49.99 | permanent, washable, never needs replacement; claims to remove pollen, dust, and pollutants with no harmful ozone emissions; made in USA | 0.38, described as much better than the 3M Basic but a little higher than desired | small particle count 4,100, large particle count 3,200 (did not do too well); static pressure 0.53, described as much better than the 3M Basic | not tested |
| 4DuPont 7500$3.99 | MERV 8, claims to reduce 75% of airborne particles from 3 to 10 microns; made in USA, 14 layers of filter media; described as the most affordable MERV 8 filter tested | 0.39, described as still a little bit high | small particle count 3,100, large particle count 2,400; static pressure was very high at 1.18 | not tested |
| 5True Blue FPR 5 (MERV 8 equivalent)$4.74 | FPR 5, stated as equivalent to MERV 8; stops dust, lint, pollen, dust mite debris, and pet dander; made in USA, 15 layers of filter media; described as the second most affordable MERV 8 filter tested | 0.33, the best MERV 8 clean-airflow result at the time it was tested, and it 'holds onto the lead' through several subsequent MERV 8 filters per the narrator's running commentary | small particle count over 9,000, large particle count 7,600 (worst dirty-filtering result of the MERV 8 filters); static pressure 0.95, high but better than DuPont's 1.18 | not tested |
| 6Aerostar MERV 8$4.99 | MERV 8, made in USA, 15 layers of filter media | 0.37, better than DuPont but not as good as True Blue | small particle count 5,000, large particle count 6,100, better filtering than True Blue; static pressure 0.74, the best static pressure of the MERV 8 filters up to that point | not tested |
| 7Nordic Pure MERV 8$5.86 | MERV 8, made in USA, 20 layers of filter media | 0.38, a little higher than desired | small particle count 4,100, large particle count 5,000, better filtering than Aerostar; static pressure 0.73, a slightly better result than Aerostar, the best static pressure of the MERV 8 filters at that point | not tested |
| 8Natural Air MERV 8 with baking soda odor eliminator$5.99 | MERV 8, claims to also handle mold, bacteria, and virus carriers in addition to the usual MERV 8 claims of pollen/dust/dust mite debris/pet dander; made in North Carolina, 16 pleats | 0.35, described as actually pretty good | small particle count 6,600, large particle count 5,500, worse filtering than DuPont, Aerostar, or Nordic Pure; static pressure 1.07, described as really struggled | not tested |
| 93M Filtrete 600 (NPR rating)$9.08 | MERV 8 but also uses 3M's proprietary NPR rating; lasts 3 months; 15 pleats; described as almost twice as expensive as other MERV 8 filters | 0.35, did pretty good | large particle count 500, small particle count 400, by far the best filtering result of any MERV 8 filter; static pressure 1.31, very high as expected given how well it filtered | not tested |
| 10Best Air (Honeywell) MERV 8, 2-inch$5.48 | MERV 8, lasts up to 90 days, made in USA, 12 filter pleats, a thicker 2-inch filter | 0.28, described as a very impressive performance that took the lead among clean-filter results at that point | small particle count just under 300, large particle count around 200; static pressure only 0.34, the best dirty-filter static pressure result up to that point, described as showing a lot of life left in the filter | not tested |
| 11Best Air (Honeywell) MERV 8, 4-inch$22.99 | MERV 8, lasts up to 1 year, made in USA, 12 filter pleats, the thickest filter tested at 4 inches | 0.23, the best clean-airflow result of any filter tested | small particle count 300, large particle count 200, almost identical to the 2-inch Honeywell; static pressure only 0.22, extremely impressive and barely different from its own clean-filter reading | not tested |
| 123M Filtrete 1085 (MERV 11 equivalent / MPR 1085)$11.97 | MERV 11 equivalent, MPR 1085 rating; lasts 90 days; made in Mexico; 20 pleats; more than twice the price of many MERV 8 filters | 0.38, a little high but not surprising for a MERV 11 filter | pre-flour baseline particle count was 57 small and 4 large; after the flour test there was no increase in particle count, described as a fantastic job; static pressure 0.8, high | disassembly and microscope inspection found only 760 square inches of filter media, a very tightly woven design that restricts both dust and air flow and has limited surface area to handle dust load before static pressure becomes critical |
| 13Honeywell FPR 7 (MERV 11 equivalent)$11.97 | FPR 7, stated as equivalent to MERV 11; captures dust, lint, airborne dust mite debris, pollen, pet dander, mold spores, and bacteria; lasts up to 3 months; made in USA; 19 pleats | 0.37, a little high but not surprising for a MERV 11 filter | no increase in particle count after the flour test, described as a fantastic job just like the 3M MERV 11; static pressure 1.01, higher than the 3M MERV 11's 0.8 | disassembly and microscope inspection found only 640 square inches of filter media, a very tightly woven design with limited surface area |
| 143M Filtrete 1900 (MERV 13)$19.97 | MERV 13, marketed for premium allergen/bacteria/virus/smoke/smog/cough and sneeze debris capture; lasts up to 3 months; made in USA with globally sourced materials; 54 pleats | 0.37, a little high but expected for a MERV 13 filter | increase of 70 small and 50 large particles after the flour test, described as still really good though slightly more passthrough than the two MERV 11 filters; static pressure only 0.52, much better than both MERV 11 filters despite the finer filtration rating | disassembly and microscope inspection found 1,560 square inches of filter media via its 54 pleats, more than twice the surface area of any other 1-inch filter tested, which the narrator says is how it overcomes the static pressure penalty normally expected from such a tightly woven MERV 13 media |
How it was tested
- clean (new) filter static pressure/airflow test using a custom test stand, manometer, and particle counter, baseline 0.16 in of water column with no filter
- dirty filter test: 1 cup of flour spread across each filter, then blower run for 1 minute, measuring small (1-5 micron) and large (5+ micron) particle passthrough and resulting static pressure
- filter media disassembly and microscope comparison, including measured surface area in square inches