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11.5x21x1 Air Filter Merv 8
11.5x21x1 AC Filter Merv 11
11.5x21x1 Furnace Filter Merv 13
11.5x21x1 Filter Merv 13 Titanium
11.5x21x1 Filter Merv 10 Carbon
11.5x21x1 Filter Merv 8 Carbon 11.5x21x1 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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11.5x21x1 Air Filter

AC Furnace Air Filter 11.5x21x1 -Inches

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Odor Eliminator

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Product Description

Item Model Number: FKFB11.5X21A
Brand: Filter King
Filter size: 11.5x21x1
Actual Size: 11.5 x 21 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, 11.5x21x1 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.

11.5x21x1 Air Filter Reviews

What MERV Rating should I choose?

How Often to Change Your 11.5x21x1 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.

11.5x21x1 Air Filter

Filter King 11.5x21x1air filters create an active layer of protection for air systems to help keep airborne irritants out of your home. Depending on its location, your home may be subject to a full range of airborne pollutants and allergens. Your home’s indoor air quality suffers over time if the incoming airflow is not filtered properly. This is where air filters come in, the tools clean up airflow so that when it comes in all it brings is freshness. The filters themselves become dirty in the process and will inevitably require replacement.

The air filters in your home become dirty over time and when they do that becomes an issue for your entire home. Airflow cannot properly travel through dirty air filters, which deprives your home of fresh air. The dirty air filters will also cause problems with their accompanying air systems by creating a rise in energy usage. The electrical spike a system undergoes affects your home’s billing and causes the mechanical parts of your air systems to wear down faster. The problems that come up only make it more important to replace your dirty air filters as soon as possible.

Filter King offers new 11.5x21x1 size air filters that are easily installed in any accompanying systems. The new filters will allow airflow to pass easily while also protecting your home against irritants. Our 11.5x21x1 size air filters have a rating of eight on the MERV (Minimum Efficiency Reporting Value) scale. The filters are capable of blocking irritants like:

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

11.5x21x1 Air Filter Delivery

Filter King offers premium 11.5x21x1 size air filters at affordable prices with quality delivery services. We also offer discounts where your orders become even more affordable, like our offer to have orders of two or more filters shipped for free. Order now and see how our services make ensuring fresh air for your easier than ever!