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Need a different depth?

Same size, deeper filter

Below is 18x25 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.

18x25x2 Shop this size 18x25x4 Built to order

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

  • 15x25x1 NaturalAire Standard MERV 8 Filters (12 pack)
    AAF Flanders

    15x25x1 NaturalAire Standard MERV 8

    $242.99
    $242.99
    Case of 12 $20.25/filter
  • 20x25x1 NaturalAire Microparticle MERV 10 85156.012025 (12 Filters)
    MERV 10
    AAF Flanders

    20x25x1 NaturalAire Microparticle MERV 10

    $152.99
    $152.99
    Case of 12 $12.75/filter
  • 18x18x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13Up to $34.13 offContact Support
    AAF Flanders

    WAREHOUSE DEAL 18x18x1 NaturalAire Healthy Ultra MERV 13

    $129.99
    $129.99 $164.12
    Case of 11 $11.82/filter
  • 18x30x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    18x30x1 NaturalAire Microparticle MERV 10

    $122.99
    $122.99
    Case of 6 $20.50/filter
  • 12x25x1 NaturalAire Standard MERV 8 84858.011225 (12 Filters)
    MERV 8
    AAF Flanders

    12x25x1 NaturalAire Standard MERV 8

    $149.99
    $149.99
    Case of 12 $12.50/filter
  • 17-1/2x29-1/2x1 NaturalAire Standard MERV 8 84858.01175295 (12 Filters)
    MERV 8
    AAF Flanders

    17-1/2x29-1/2x1 NaturalAire Standard MERV 8

    $170.99
    $170.99
    Case of 12 $14.25/filter
  • 16x25x4-1/2 NaturalAire Choice Allergen MERV 8 82655.0451625 (2 Filters)
    MERV 8
    AAF Flanders

    16x25x4-1/2 NaturalAire Choice Allergen MERV 8

    $104.99
    $104.99
    Case of 2 $52.50/filter
  • 20x20x1 NaturalAire Standard MERV 8 84858.012020 (12 Filters)
    MERV 8
    AAF Flanders

    20x20x1 NaturalAire Standard MERV 8

    $104.99
    $104.99
    Case of 12 $8.75/filter
  • 10x25x1 NaturalAire Standard MERV 8 Filters (12 pack)
    AAF Flanders

    10x25x1 NaturalAire Standard MERV 8

    $232.99
    $232.99
    Case of 12 $19.42/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
  • 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
  • 20x25x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    20x25x1 NaturalAire Healthy Ultra MERV 13

    $191.99
    $191.99
    Case of 12 $16.00/filter
  • 25x30x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    25x30x1 NaturalAire Healthy Ultra MERV 13

    $380.99
    $380.99
    Case of 12 $31.75/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
  • 18x20x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    18x20x1 NaturalAire Microparticle MERV 10

    $204.99
    $204.99
    Case of 12 $17.08/filter
  • 17-1/2x23-1/2x1 NaturalAire Standard MERV 8 84858.01175235 (12 Filters)
    AAF Flanders

    17-1/2x23-1/2x1 NaturalAire Standard MERV 8

    $156.99
    $156.99
    Case of 12 $13.08/filter
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