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21.5x24x1 Air Filter Merv 8
21.5x24x1 AC Filter Merv 11
21.5x24x1 Furnace Filter Merv 13
21.5x24x1 Filter Merv 13 Titanium
21.5x24x1 Filter Merv 10 Carbon
21.5x24x1 Filter Merv 8 Carbon 21.5x24x1 Filter Merv 8 Carbon
Protects All Against
  • Pollen protection
  • Dust protection
  • Mold protection
  • Dust Mites protection
    Dust Mites
  • Bacteria protection
  • Pet Dander protection
    Pet Dander
  • Smoke protection
  • Viruses protection
  • Cooking Smoke protection
  • Odor protection
  • Smog protection
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21.5x24x1 Air Filter

AC Furnace Air Filter 21.5x24x1 -Inches

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Odor Eliminator

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Product Description

Item Model Number: FKFB21.5X24A
Brand: Filter King
Filter size: 21.5x24x1
Actual Size: 21.5 x 24 x .75
1-Inch Filter
MERV 8 Filter Rating
Protection From: Pollen, Dust, Mold, Dust Mites, Bacteria, Pet Dander, Smoke, Viruses
Residential / Commercial Use

Manufactured in the US

Why Buy Air Filters From Filter King?


In comparison to fiberglass filters, 21.5x24x1 pleated air filters are at least 20 times more effective. All Filter King air filters are made in the US.


Filters frames are made out of heat resistant paperboard with horizontal grid supports. Able to withstand temperatures of up to 200° F and resistant to moisture, the paperboard frames do not support microbial growth and outperforms traditional cardboard frames.


Chemical free, electrostatically charged synthetic polyester media is pleated, maximizing the surface area, to capture a high number of airborne particles as small as 0.3 microns with low air flow resistance. To increase durability, the media is supported with a corrosion resistant steel wire.

21.5x24x1 Air Filter Reviews

What MERV Rating should I choose?

How Often to Change Your 21.5x24x1 Air Filter?

Filter King AC & furnace filters aren’t the typical fiberglass filters that need to be replaced every 30 days. Our filters can typically be used for 3 to 5 months before requiring to be changed. Naturally, a variety of things influence filter lifespan.

Some of the factors that influence your filter’s life include outdoor air quality, whether pets are in the home, and how well your HVAC system is maintained.

Your air filter becomes clogged over time by trapped particles, preventing airflow. The efficiency of the HVAC filter declines. Your system must work harder to heat and cool your home. The extra strain on the HVAC system causes higher energy bills. Regular home air filter replacements can prevent expensive system repairs or replacements down the road.

You should change your filter more frequently if you notice:

  • Household dust build-up
  • The air isn’t cooling as is used to
  • There’s more dust near the air vents
  • A dirty filter surface
  • Higher energy bills
  • Burning smells near your HVAC system.

21.5x24x1 Air Filter

Filter King 21.5x24x1 air filters are an important part of your air systems and keep air flowing in clean of irritants. The filters themselves consist of a tight mesh weaving that allow airflow to pass through smoothly while also being cleaned. This process raises home air quality and makes your residence more comfortable and safe. The air filters in your systems will continue to work until they become completely covered in particles. As they become dirty, they start causing issues for their systems and your home as a whole.

Dirty air filters are a problem for your home since fresh air flow is not able to pass through effectively. Without fresh air, your home will begin to experience problems with dryness and stagnation over time. There may also be issues with particles like smoke or dander when your air systems cannot pump them out. The air systems themselves will become strained as they try to push airflow through the dirty filters. This may lead to mechanical damage and a rise in energy billing over time.

Your home will need new air filters installed frequently in order to keep the airflow coming in without any issues. Filter King offers fresh, new 21.5x24x1 size filters ready for delivery and use in your homes air systems. We also offer a subscription option where new air filters are delivered regularly to your home. Any orders of two or more filters are shipped out for free. Our filters have a MERV rating of eight and block out irritants like:

  • Pollen
  • Dust
  • Mold
  • Dust Mites
  • Bacteria
  • Pet Dander
  • Smoke
  • Viruses

21.5x24x1 Furnace Filters

Your furnace filters will clean out the heated air flow passing through into the vents throughout your home. The filters become dirtier over time and begin to cause issues for their system and your home as a whole. The heated airflow will build up behind a dirty filter and cause temperatures to rise to problematic degrees in the systems. Your home will also suffer from temperature fluctuations since no heated air is coming through. Avoid these issues and order new air filters for your home today.