Furnace Filters
Best 20x20 AC Filter (2026): Our 5 Picks Ranked
As an Amazon Associate I earn from qualifying purchases. Specs below come from each product's Amazon listing; we do not test products in person.
For the best 20x20 ac filter search, the Aerostar MERV 13 6-pack leads with electrostatically charged pleated fibers and a 3-month service life, while the Filter King MERV 8 12-pack suits buyers who keep spare filters on hand. The Filtrete MERV 14 2-pack carries the highest MERV rating here, and the Reair washable filter covers buyers who prefer washing over replacing.
Starting out? See the main guide: Best Furnace Air Filters
Top picks at a glance
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Best OverallAerostar Air Filter 20x20x1 MERV 13 AC9.8 View on Amazon -
Runner-UpFilter King 20x20x1 Air Filter MERV9.7 View on Amazon -
Also GreatSimply 20x20x1 Air Filter9.5 View on Amazon -
Also GreatFiltrete 20x20x1 Air Filter9.5 View on Amazon -
Also GreatReair 20x20x1 Air filter9.2 View on Amazon
Compare the specs
Ranked on pack size from each listing, plus how many buyers have rated it. A dash (—) means we could not confirm that figure from the listing.
| Pick | MERV rating | Pack size | Weight | Warranty |
|---|---|---|---|---|
| 1. Aerostar Air Filter 20x20x1 MERV 13 AC | MERV 13 | 6-pack | — | — |
| 2. Filter King 20x20x1 Air Filter MERV | MERV 8 | 12-pack | — | — |
| 3. Simply 20x20x1 Air Filter | MERV 13 | 6-pack | — | — |
| 4. Filtrete 20x20x1 Air Filter | MERV 14 | — | — | — |
| 5. Reair 20x20x1 Air filter | MERV 8 | — | — | 5-year |
Aerostar Air Filter 20x20x1 MERV 13 AC
MERV 13 filtration in a 6-pack, with electrostatically charged pleated fibers and a 3-month service life.
- MERV rating: MERV 13
- Pack size: 6-pack
Good for
- Buyers who want MERV 13 filtration for a 1-inch slot
- Buyers who want six filters in one pack
Skip it if
- You need a MERV rating above 13
- You want more than six filters per pack
Actual size 19.75 by 19.75 by 0.75 inches, fitting a standard 1-inch filter slot. The MERV 13 media captures up to 98% of airborne particles, and the heavy-duty beverage board frame with moisture-resistant backing runs up to 3 months.
Filter King 20x20x1 Air Filter MERV
MERV 8 filtration in a 12-pack, with a pleated design and up to 90 days between changes.
- MERV rating: MERV 8
- Pack size: 12-pack
Good for
- Buyers who want twelve filters in one pack
- Buyers who want MERV 8 filtration
Skip it if
- You need a MERV rating above 8
- You need MERV 13 filtration or higher
The pleated design traps airborne particles without cutting airflow, and the maker recommends changing a 1-inch filter every 30 to 90 days, with up to 90 days of service here.
Simply 20x20x1 Air Filter
MERV 13 filtration in a 6-pack, with a higher pleat count and a 3-month service life.
- MERV rating: MERV 13
- Pack size: 6-pack
Good for
- Buyers who want MERV 13 filtration at a higher pleat count
- Buyers who want American-made filters with recycled materials
Skip it if
- You need a MERV rating above 13
- You want twelve filters in one pack
Actual size 19.75 by 19.75 by 0.75 inches, working with almost any brand in a 1-inch slot. The pleated media traps 95% of airborne particles, and each filter runs up to 3 months with airflow arrows for the slot.
Filtrete 20x20x1 Air Filter
MERV 14 filtration with MPR 2800, in a 2-pack, with 3-in-1 technology from 3M.
- MERV rating: MERV 14
Good for
- Buyers who want MERV 14 filtration
- Buyers who want MPR 2800 ultrafine particle reduction
Skip it if
- You need a MERV rating above 14
- You want more than two filters per pack
Actual size 19.69 by 19.69 by 0.81 inches for a 1-inch slot. The 3-in-1 technology traps microscopic particles, with 81% small particle capture for 0.3 to 1 micron particles, and the maker advises changing 1-inch filters at least every 90 days.
Reair 20x20x1 Air filter
A washable, reusable MERV 8 filter with a snap-on frame, a storage case and a 5-year warranty.
- MERV rating: MERV 8
- 5-year warranty stated
Good for
- Buyers who want a washable filter instead of disposables
- Buyers who want a 5-year warranty on a filter
Skip it if
- You need a MERV rating above 8
- You prefer throwaway filters over washing one
Pressure drop is 0.38 w.g. at 1367 CFM and 0.54 w.g. at 1750 CFM, and the filter washes every 30 to 60 days with a snap-on frame and storage case included.
How to choose
Match the MERV rating to your need
MERV 13 and MERV 14 filters capture smaller particles than MERV 8 filters, and this list splits that way: the Aerostar and Simply sit at MERV 13, the Filtrete at MERV 14 with MPR 2800, and the Filter King and Reair at MERV 8. A higher rating is not automatically better for every system, since the Aerostar media traps particles without restricting airflow. Pick the rating your system manual allows, then compare pack size and service life.
Count the pack and the service life
Service life runs up to 3 months for the Aerostar and Simply and up to 90 days for the Filter King, while the Filtrete maker advises changing 1-inch filters at least every 90 days, and the Reair washes every 30 to 60 days.
Check the actual size before ordering
Filters sold as 20 by 20 by 1 inches carry actual sizes in their listings, so compare the actual size with your slot: the Aerostar and Simply measure 19.75 by 19.75 by 0.75 inches, the Filter King 19.5 by 19.5 by 0.75 inches, and the Filtrete 19.69 by 19.69 by 0.81 inches. The Reair is sized 20 by 20 by 1 inches with a snap-on frame. Measure the slot first, then match the actual size, since a filter that does not fit the slot cannot do its job.
FAQ
What does a MERV rating tell you?
It ranks how finely a filter captures particles: this list runs from MERV 8 for the Filter King and Reair up to MERV 14 for the Filtrete, with the Aerostar and Simply at MERV 13.
When should a 20 by 20 by 1 inch filter change?
The Aerostar and Simply run up to 3 months, the Filter King up to 90 days, and the Filtrete maker advises changing 1-inch filters at least every 90 days, while the Reair washes every 30 to 60 days.
Can one washable filter replace disposable filters?
The Reair is machine-washable with a honeycomb structure and a snap-on frame, and it washes every 30 to 60 days, so it serves across many changes instead of one throwaway filter per change.
