All filters are made in the USA + Free Shipping on orders over $50

21.5x23.25x1 Air Filter Merv 8
21.5x23.25x1 AC Filter Merv 11
21.5x23.25x1 Furnace Filter Merv 13
21.5x23.25x1 Filter Merv 13 Titanium
21.5x23.25x1 Filter Merv 10 Carbon
21.5x23.25x1 Filter Merv 8 Carbon 21.5x23.25x1 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
{{ filter_count }} Pack of

21.5x23.25x1 Air Filter

AC Furnace Air Filter 21.5x23.25x1 -Inches

1. Select Filter Quality

Odor Eliminator

2. Select Quantity

${{ money(priceWithoutDiscount()) }} Save ${{ money(savePrice()) }} ({{ savePercent()}}%)


Product Description

Item Model Number: FKFB21.5X23.25A
Brand: Filter King
Filter size: 21.5x23.25x1
Actual Size: 21.5 x 23.25 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, 21.5x23.25x1 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.

21.5x23.25x1 Air Filter Reviews

What MERV Rating should I choose?

How Often to Change Your 21.5x23.25x1 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.

21.5x23.25x1 Air Filter

Filter King 21.5x23.25x1 size air filters are significant parts of any air systems' ability to clean out incoming airflow. These tools consist of a tight mesh weaving that was ergonomically designed to allow airflow to pass through but stop irritants from entering your systems. The clean air is then able to enter your home and cycle through its various rooms to provide a fresh, clean smell throughout. Indoor air quality rises while your home becomes safer to stay in as the air remains clean. The process is consistent, your air filter will not stop cleaning out incoming airflow, until the filters become too dirty to work effectively.

Your air systems use their filters continuously until they have become completely covered in the particles they are meant to capture. At this point, the filters become a blockage for your system that cause several problems throughout your home. When air is unable to travel through your systems then the air already inside your home will begin to dry out and stagnant over time. Your air systems are affected by the blockage as well, and in their attempts to fix the problem may cause more instead. Your air systems will try to push airflow through the dirty filter, which lead to a rise in energy billing and possibly even mechanical failure.

You will need to frequently swap out your old air filters for new ones in order to keep the air flowing into your home smoothly. Filter King has a full stock of available 21.5x23.25x1 size air filters ready for use in your home. We offer a delivery service to have the filters delivered right to you, with a subscription option that has them regularly shipped out. Orders of two or more filters are even shipped out for free. The filters have a MERV (Minimum Efficiency Reporting Value) rating of eight, showing that they can block out particles like:

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

21.5x23.25x1 Furnace Filters

The air filters you order are usable in multiple air systems, which includes your furnace systems. Furnace filters require frequent replacement in order to keep the air coming in smoothly and without any issues. Dirty furnace filters are a problem that will cause issues throughout your home as the heated airflow builds up over time. You need to keep the air filters in your furnaces clean, or they could cause temperature problems and suffer mechanical damage.