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Need a different depth?

Same size, deeper filter

Below is 21x21 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.

21x21x2 Built to order 21x21x4 Built to order

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

  • 22x22x1 NaturalAire Standard MERV 8 84858.012222 (12 Filters)
    MERV 8
    AAF Flanders

    22x22x1 NaturalAire Standard MERV 8

    $155.99
    $155.99
    Case of 12 $13.00/filter
  • 14x24x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    14x24x1 NaturalAire Healthy Ultra MERV 13

    $248.99
    $248.99
    Case of 12 $20.75/filter
  • 14x30x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    14x30x1 NaturalAire Healthy Ultra MERV 13

    $234.99
    $234.99
    Case of 12 $19.58/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
  • 20x22x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    20x22x1 NaturalAire Healthy Ultra MERV 13

    $329.99
    $329.99
    Case of 12 $27.50/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
  • 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
  • 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
  • 18x25x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    18x25x1 NaturalAire Healthy Ultra MERV 13

    $332.99
    $332.99
    Case of 12 $27.75/filter
  • 18x30x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    18x30x1 NaturalAire Healthy Ultra MERV 13

    $326.99
    $326.99
    Case of 12 $27.25/filter
  • 15x30x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    15x30x1 NaturalAire Healthy Ultra MERV 13

    $328.99
    $328.99
    Case of 12 $27.42/filter
  • 25x25x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    25x25x1 NaturalAire Healthy Ultra MERV 13

    $230.99
    $230.99
    Case of 12 $19.25/filter
  • 20x24x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    20x24x1 NaturalAire Healthy Ultra MERV 13

    $204.99
    $204.99
    Case of 12 $17.08/filter
  • WAREHOUSE DEAL 16x20x1 NaturalAire Standard MERV 8 84858.011620 (12 Filters)
    MERV 8Up to $17 off
    AAF Flanders

    WAREHOUSE DEAL 16x20x1 NaturalAire Standard MERV 8

    Only 1 left
    $79.99
    $79.99 $96.99
    Case of 12 $6.67/filter
  • 16x16x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    16x16x1 NaturalAire Healthy Ultra MERV 13

    $275.99
    $275.99
    Case of 12 $23.00/filter
  • 17-1/2x23-1/2x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    17-1/2x23-1/2x1 NaturalAire Healthy Ultra MERV 13

    $201.99
    $201.99
    Case of 12 $16.83/filter
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