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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.

  • 10x20x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    10x20x1 NaturalAire Microparticle MERV 10

    $71.99
    $71.99
    Case of 6 $12.00/filter
  • 15x20x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    15x20x1 NaturalAire Microparticle MERV 10

    $167.99
    $167.99
    Case of 12 $14.00/filter
  • 20x22x1 NaturalAire Standard MERV 8 Filters (12 pack)
    MERV 8
    AAF Flanders

    20x22x1 NaturalAire Standard MERV 8

    $179.99
    $179.99
    Case of 12 $15.00/filter
  • 16x20x1 NaturalAire Microparticle MERV 10 85156.011620 (12 Filters)
    MERV 10
    AAF Flanders

    16x20x1 NaturalAire Microparticle MERV 10

    $116.99
    $116.99
    Case of 12 $9.75/filter
  • 20x25x3 NaturalAire Choice Allergen MERV 8 82655.032025 (3 Filters)
    MERV 8Contact Support
    AAF Flanders

    20x25x3 NaturalAire Choice Allergen MERV 8

    $210.99
    $210.99
    Case of 3 $70.33/filter
  • 15x20x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    15x20x1 NaturalAire Microparticle MERV 10

    $89.99
    $89.99
    Case of 6 $15.00/filter
  • 20x30x1 NaturalAire Microparticle MERV 10 85156.012030 (12 Filters)
    MERV 10
    AAF Flanders

    20x30x1 NaturalAire Microparticle MERV 10

    $171.99
    $171.99
    Case of 12 $14.33/filter
  • 18x18x1 NaturalAire Standard MERV 8 Filters (12 pack)
    MERV 8
    AAF Flanders

    18x18x1 NaturalAire Standard MERV 8

    $103.99
    $103.99
    Case of 12 $8.67/filter
  • 18x18x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    18x18x1 NaturalAire Healthy Ultra MERV 13

    $195.99
    $195.99
    Case of 12 $16.33/filter
  • 16x20x1 NaturalAire Microparticle MERV 10 85256.011620 (6 Filters)
    MERV 10
    AAF Flanders

    16x20x1 NaturalAire Microparticle MERV 10

    $69.99
    $69.99
    Case of 6 $11.67/filter
  • 20x22-1/4x1 NaturalAire Standard MERV 8 84858.01202225 (12 Filters)
    MERV 8
    AAF Flanders

    20x22-1/4x1 NaturalAire Standard MERV 8

    $173.99
    $173.99
    Case of 12 $14.50/filter
  • 20x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13Up to $40.31 off
    AAF Flanders

    WAREHOUSE DEAL 20x20x1 NaturalAire Healthy Ultra MERV 13

    Only 1 left
    $142.99
    $142.99 $183.30
    Case of 10 $14.30/filter
  • 14x20x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    14x20x1 NaturalAire Healthy Ultra MERV 13

    $230.99
    $230.99
    Case of 12 $19.25/filter
  • 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
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