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20x21.5x1 Air Filter Merv 8
20x21.5x1 AC Filter Merv 11
20x21.5x1 Furnace Filter Merv 13
20x21.5x1 Filter Merv 13 Titanium
20x21.5x1 Filter Merv 10 Carbon
20x21.5x1 Filter Merv 8 Carbon 20x21.5x1 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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20x21.5x1 Air Filter

AC Furnace Air Filter 20x21.5x1 -Inches

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Odor Eliminator

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Product Description

Item Model Number: FKFB20X21.5A
Brand: Filter King
Filter size: 20x21.5x1
Actual Size: 20 x 21.5 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, 20x21.5x1 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.

20x21.5x1 Air Filter Reviews

What MERV Rating should I choose?

How Often to Change Your 20x21.5x1 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.

20x21.5x1 Air Filter

Filter King 20x21.5x1  air filters protect your home by cleaning out incoming airflow free of harmful irritants. The airflow in your home is constantly coming through your systems, but they have no way to tell the clean air from the dirty. AC and furnace filters are made of a tight mesh weaving that allows airflow to pass through naturally, while particles are captured and absorbed. The process cleanses the airflow, but the filters become dirtier over time and cause indoor air quality to dip. Eventually, air filter replacement is required in order to keep the air coming in without any issues.

Your air filters will become covered in particles over time as they continue to capture and absorb them. The dirty air filters eventually become so covered in particles that they are cannot effectively allow airflow to pass through. Without fresh airflow, the air inside your home is subjected to drying out and stagnation. Your air systems also become more strained as they try to push airflow through the blockage. The resulting effort caused mechanical problems and leads to a rise in energy billing.

Your home air filters need regular maintenance in order to keep airflow coming in smooth and clean. Filter King offers new, fresh 20x21.5x1 air filters that are installable upon their arrival. We also have air filter delivery service, along with a subscription option, where orders of two or more filters are shipped for free. Filter King model filters have a MERV  rating(Minimum Efficiency Reporting Value) rating of eight and block out more than 90% of all particles less than 3 microns. Such particles include:

  • Pollen
  • Dust & Lint
  • Mold & Mildew
  • Fine dust & other dust particles
  •  Fumes & Odors
  • Dust Mites
  • Bacteria
  • Smoke
  • Viruses
  • Mold spores
  • Allergy, asthma, and other airborne particles

Furnace Air Filter 20x21.5x1

Your AC and furnace filters work in the system to clean heated airflow before distribution into your home. Your filters will continue working until they become dirty, and at this point they become a problem that needs addressing. Heated airflow needs release, or the furnace temperature begins to rise to a high degree. If the temperatures are too high, then the furnace may become damaged and require some expensive repairs. Your home will also see temperature fluctuations when the heated airflow is not able to warm its rooms. Order our new high-quality filters today and keep airflow coming in through your systems without issue.