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

Call Us C877.570.9755

20x40x1 Air Filter Merv 8
20x40x1 AC Filter Merv 11
20x40x1 Furnace Filter Merv 13
20x40x1 Filter Merv 13 Titanium
20x40x1 Filter Merv 10 Carbon
20x40x1 Filter Merv 8 Carbon 20x40x1 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

20x40x1 Air Filter

AC Furnace Air Filter 20x40x1 -Inches

1. Select Filter Quality

Odor Eliminator

2. Select Quantity

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


Product Description

Item Model Number: FKFB20X40
Brand: Filter King
Filter size: 20x40x1
Actual Size: 19.5 x 39.5 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, 20x40x1 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.

20x40x1 Air Filter Reviews

What MERV Rating should I choose?

How Often to Change Your 20x40x1 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.

20x40x1 Air Filter

Filter King 20x40x1 size air filters are tools necessary to keeping the air pumped in by your home systems clean. The air filters consist of a tight mesh weaving designed to capture allergens and pollutants, while airflow goes through. The cleaned up air will cycle into your home and cycle through its room, raising indoor air quality. Without the filters, your home is subjected to any number of allergens and pollutants in the surrounding air. Your air filters will continuously clean out incoming airflow, but they become dirtier in the process.

Dirty air filters cause several problems to develop for their systems, and only become dirtier over time. Eventually, the dirty filters in your home will also begin to affect the entire household as they block incoming airflow. Without fresh air to cycle into your home, it will face issues of dryness and stagnation. Your air systems also have problems as they try to push airflow through the blockage. The effort will lead to possible mechanical damage and a rise in energy billing over time.

Your home systems work best when they have fresh, clean air filters installed and cleaning passing airflow. Filter King offers new 20x40x1 size air filters ready for order and capable of installation upon arrival. We offer a premium delivery service, orders of two or more are shipped for free. With our subscription option you could have new filters arrive at your home as often as monthly. Filter King model filters rate as an eight on the MERV (Minimum Efficiency Reporting Value) scale. This means that they filter out particles like:

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

20x40x1 Furnace Filters

Your furnace air filters are necessary to keep the heated airflow passing through the system clean of irritants. When the furnace air filters in your home become dirty they cause the regular problems with blocked airflow and loss of fresh air. They also cause additional issues since the heated airflow begins to build up and internal temperatures to rise. If not replaced, the dirty air filters may cause mechanical damages and a rise in energy billing for your home. Order new air filters now and enjoy air coming in without problems throughout your home.