Filterbuy 18x20x4 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 6-Pack
Filterbuy 18x20x4 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 6-Pack
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Filterbuy 18x20x4 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 6-Pack

|20.9K ratings

Key item features

  • UNIVERSAL COMPATIBILITY: 18x20x4 replacement air filters for your furnace, air conditioner, or heat pump enhance HVAC system efficiency and support a healthy lifestyle (actual size: 17.50" x 19.50" x 3.63")
  • 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 8 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

4.6 out of 5 stars
stars
20.9K ratings7,021 reviews
How item rating is calculated
  1. 5 stars82% (17.1K)
  2. 4 stars8% (1,767)
  3. 3 stars3% (689)
  4. 2 stars2% (381)
  5. 1 star4% (899)
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Showing 1-3 of 7,021 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?3AX7UREWEUM9197734231
Aug 20, 2026
Reviewer name: Customer
5 out of 5 stars
5 out of 5 stars review

Affordable and effective

I love these filters. Affordable and effective. It's amazing to see how much they have collected when it's time to change them. The subscription service is great. A little extra savings and a subtle reminder that you forgot to change them. LOL. But I usually notice when it's time if I forget, I find myself sneezing and having itchy eyes in the house. Which always improves once I change them Highly recommend these and Filterbuy

Review from Filterbuy
Helpful?3AX7UREWEUM9197734231
Jul 7, 2026
Reviewer name: Customer
5 out of 5 stars
5 out of 5 stars review

Great Filter

I have been using Filterbuy filters for numerous years and change them out regularly. I have always been pleased with just how good of a filter they are compared to other filters that do not even compare in quality. The price is very reasonable so that is why I always purchase 12 filters at a time and I received them within 2 days of ordering. I will continue using Filterbuy so I do not have to worry about my filters being great!

Review from Filterbuy
Helpful?3AX7UREWEUM9197734231
Current price is $178.98
Price when purchased online
  • Free shipping
  • Free 30-day returns
Subscribe, Your usuals, on your schedule, Save time and stay stocked!, $178.98
Your usuals, on your schedule
Save time and stay stocked!
One-time purchase $178.98

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Arrives by Fri, Sep 11
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Sold and shipped by FilterbuyPro Seller
4.592502756339581 out of 5 stars
4.592502756339581 stars out of 5, based on 4535 seller reviews(4.6)
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