Filterbuy 20x21x1 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 4-Pack
Filterbuy 20x21x1 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 4-Pack
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Filterbuy 20x21x1 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 4-Pack

|11.8K ratings

Key item features

  • UNIVERSAL COMPATIBILITY: 20x21x1 replacement air filters for your furnace, air conditioner, or heat pump enhance HVAC system efficiency and support a healthy lifestyle (actual size: 19.50" x 20.50" x 0.75")
  • MERV 11 PERFORMANCE: Protect your home or business from allergens, pets, and more with MERV 11 synthetic media (comparable with MPR 1200 & FPR 7) that captures 95% of dust without restricting air flow
  • LONG-LASTING FILTRATION: Electrostatically charged media with 14 pleats per foot traps more microscopic particles and lasts 3x longer than fiberglass models (replace every 90 days for optimal performance)
  • SUPERIOR CONSTRUCTION: Easy installation beverage board frames with dual wire backing outperform flimsy cardboard designs by improving durability, preventing warping, and resisting extreme temperatures
  • MADE IN THE USA: Built with industrial-grade, recyclable materials and proudly manufactured 100% in the United States for dependable indoor air quality that is trusted by millions of homes

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Customer ratings & reviews

4.7 out of 5 stars
stars
11.8K ratings3,956 reviews
How item rating is calculated
  1. 5 stars85% (10K)
  2. 4 stars8% (931)
  3. 3 stars3% (309)
  4. 2 stars1% (148)
  5. 1 star3% (403)
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Showing 1-3 of 3,956 reviews

Jul 6, 2026
Reviewer name: Customer
5 out of 5 stars
5 out of 5 stars review

Great filter

The filter is so solid. I previously bought this flimsy filter that bowed immediately and got sucked up into the HVAC unit. After that terrible experience, I had to find a better option. This filter is excellent—well constructed and filtering out inpurities.

Review from Filterbuy
Helpful?3ZK5LKA3F5H4963661265
Sep 12, 2026
Reviewer name: Customer
5 out of 5 stars
5 out of 5 stars review

To early to tell

Just received the filters. Best part is they actually fit properly. My 20x30 opening was 19 7/8”x 29 7/8”. Sam's filters were actual size and had to be bent to fit, which damaged the sealing edge. My 3 ton unit really moves some air and bows the filter pretty good. But, time will tell. Bought the six pack to start with. We'll see in 6 months if I buy again.

Review from Filterbuy
Helpful?3ZK5LKA3F5H4963661265
Sep 3, 2026
Reviewer name: Customer
5 out of 5 stars
5 out of 5 stars review

The quality of the cardboard

The quality of the cardboard used to stabilize the filter is far above anything I have bought at the big box stores. . I used to be in the HVAC industry so believe me when I say the cost is very reasonable. I will definitely be a customer for life. Thanks for making such a quality product. .

Review from Filterbuy
Helpful?3ZK5LKA3F5H4963661265
Current price is $74.96
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  • Free 30-day returns
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Sold and shipped by FilterbuyPro Seller
4.594300630846204 out of 5 stars
4.594300630846204 stars out of 5, based on 4597 seller reviews(4.6)
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