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4" MERV 8 Furnace & AC Air Filter by Filters Fast®

FF4M8E

$24.95
Retail: $34.99 /ea
You Save: 29%
As low as
$24.95
Retail: $34.99
You Save: 29%
FF4M8 Sizes :
Ships by Tomorrow 6/8/2026
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Frequently Bought With This Item

The 4" MERV 8 Furnace & AC Air Filter by Filters Fast® is a MERV 8 filter that effectively reduces contaminants from your indoor air. Removing these airborne particles can help improve allergies and alleviate sinus irritation that can cause watery eyes, itchy throat, coughing, and sneezing. The Filters Fast® MERV 8 filter media is electrostatically charged and constructed with spun micro-fiber that also will not retain moisture, which can lead to microbial growth. Aside from the health benefits, these HVAC filters will also extend the life of your heating and cooling system by making it work more efficiently.

Note: This filter does not contain fiberglass.

Specifications:

  • Brand: Filters Fast®
  • Part Number: FF4M8E
  • Pack Size: 1
  • Filter Life: 6 - 12 Months
  • MERV Rating: 8
  • Filter Type: Electrostatic pleated
  • Material: Synthetic
  • For commercial and residential use

Available Sizes:

The 4" MERV 8 Furnace & AC Air Filter by Filters Fast® is available in the following sizes:

Nominal Size Actual Size Alternate Part Number
12x24x4 Air Filter 11.375x23.375x3.625 PF8.0412243PFF
16x20x4 Air Filter 15.375x19.375x3.625 PF8.0416203PFF
16x25x4 Air Filter 15.375x24.375x3.625 PF8.0416253PFF
18x24x4 Air Filter 17.375x23.375x3.625 PF8.0418243PFF
20x20x4 Air Filter 19.375x19.375x3.625 PF8.0420203PFF
20x24x4 Air Filter 19.375x23.375x3.625 PF8.0420243PFF
20x25x4 Air Filter 19.375x24.375x3.625 PF8.0420253PFF
24x24x4 Air Filter 23.375x23.375x3.625 PF8.0424243PFF
25x29x4 Air Filter 24.375x28.375x3.625 PF8.0425293PFF

Custom Sizes:

  • If you don' t see your size, order a custom made air filter! Custom made air filters do not come individually wrapped.

How do you install the 4" MERV 8 Furnace & AC Air Filter by Filters Fast®?

  1. Once your air filters arrive, gather your supplies including a ladder (if needed,) safety goggles, gloves, a mask, and a disposable bag.
  2. Remove the metal grate from your air return.
  3. Carefully remove the used air filter and place it immediately and gently into the disposable bag. Then tie the bag sealed.
  4. Place the new air filter in place of the filter you just removed and replace the metal grille.

How often should you replace the 4" MERV 8 Furnace & AC Air Filter by Filters Fast®?

  • Changing your 4" MERV 8 Furnace & AC Air Filter by Filters Fast® is a very quick and easy process that should be done once every six to twelve months.

What contaminants does the 4" MERV 8 Furnace & AC Air Filter by Filters Fast® reduce?

  • The 4" MERV 8 Furnace & AC Air Filter by Filters Fast® is a MERV 8 air filter, which means that it reduces the following contaminants:

    • Dust
    • Pollen
    • Mold Spores
    • Other Common Airborne Allergens

Compatible Parts:

The 4" MERV 8 Furnace & AC Air Filter by Filters Fast® is the correct replacement for the following part numbers:

Part Number
PF80412241P
PF80416201P
PF80416251P
PF80418241P
PF80420201P
PF80420241P
PF80420251P
PF80424241P
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Customer Reviews:

Total Reviews: 1 Average Rating: 5 / 5.0

Filtersfast Reviews on Trust Pilot external site
customer2026-02-07

Only thing that I have a problem with is not having a 5 inch wide filter.

Collected by Trustpilot.com


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