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Need a different depth?

Same size, deeper filter

Below is 18x20 at 1 naturalaire″. A thicker filter holds more before it loads up, so it lasts longer between changes and puts less strain on the blower — we carry the same width and height in the depths below.

18x20x2 Shop this size 18x20x4 Built to order

Ordering for a building? Ask for volume pricing or call 1-866-469-8556.

  • 18x18x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    18x18x1 NaturalAire Microparticle MERV 10

    $114.99
    $114.99
    Case of 6 $19.17/filter
  • 14x20x1 NaturalAire Standard MERV 8 84858.011420 (12 Filters)
    MERV 8
    AAF Flanders

    14x20x1 NaturalAire Standard MERV 8

    $96.99
    $96.99
    Case of 12 $8.08/filter
  • 12x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    12x20x1 NaturalAire Healthy Ultra MERV 13

    $268.99
    $268.99
    Case of 12 $22.42/filter
  • 15x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    15x20x1 NaturalAire Healthy Ultra MERV 13

    $281.99
    $281.99
    Case of 12 $23.50/filter
  • 18x25x1 NaturalAire Standard MERV 8 Filters (12 pack)
    AAF Flanders

    18x25x1 NaturalAire Standard MERV 8

    $246.99
    $246.99
    Case of 12 $20.58/filter
  • 15x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    Up to $10.39 off
    AAF Flanders

    WAREHOUSE DEAL 15x20x1 NaturalAire Healthy Ultra MERV 13

    Only 1 left
    $149.99
    $149.99 $160.38
    Case of 11 $13.64/filter
  • 18x18x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    18x18x1 NaturalAire Microparticle MERV 10

    $261.99
    $261.99
    Case of 12 $21.83/filter
  • 12x20x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    12x20x1 NaturalAire Microparticle MERV 10

    $109.99
    $109.99
    Case of 12 $9.17/filter
  • 10x20x1 NaturalAire Standard MERV 8 Filters (12 pack)
    MERV 8Up to $30.76 offContact Support
    AAF Flanders

    WAREHOUSE DEAL 10x20x1 NaturalAire Standard MERV 8

    $59.99
    $59.99 $90.75
    Case of 11 $5.45/filter
  • 13x20x1 NaturalAire Standard MERV 8 Filters (12 pack)
    AAF Flanders

    13x20x1 NaturalAire Standard MERV 8

    $232.99
    $232.99
    Case of 12 $19.42/filter
  • 14x20x1 NaturalAire Odor Eliminator with Baking Soda MERV 8 air filter
    MERV 8
    AAF Flanders

    14x20x1 NaturalAire Odor Eliminator with Baking Soda MERV 8

    $62.99
    $62.99
    Case of 4 $15.75/filter
  • 18x24x1 NaturalAire Microparticle MERV 10 85156.011824 (12 Filters)
    MERV 10
    AAF Flanders

    18x24x1 NaturalAire Microparticle MERV 10

    $148.99
    $148.99
    Case of 12 $12.42/filter
  • 18x30x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    18x30x1 NaturalAire Microparticle MERV 10

    $246.99
    $246.99
    Case of 12 $20.58/filter
  • 20x36x1 NaturalAire Standard MERV 8 84858.012036 (12 Filters)
    MERV 8
    AAF Flanders

    20x36x1 NaturalAire Standard MERV 8

    $186.99
    $186.99
    Case of 12 $15.58/filter
  • 12x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    Up to $79.21 off
    AAF Flanders

    WAREHOUSE DEAL 12x20x1 NaturalAire Healthy Ultra MERV 13

    Only 1 left
    $129.99
    $129.99 $209.20
    Case of 10 $13.00/filter
  • 14x18x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    14x18x1 NaturalAire Microparticle MERV 10

    $217.99
    $217.99
    Case of 12 $18.17/filter
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