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21×23.25×1 – Merv 11

21×23.25×1 – Merv 11
AC Furnace Air Filter
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Product Description

Filter Size: 21×23.25x1A

Actual Size: 21×23.25×1

Actual Size Fraction : 21×23-1/4×1

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Shop Quality 21×23.25×1 Air filters Online

A quality air filter reduces the chance of spreading the irritants around your home while allowing clean air to pass through.

Custom Filters Direct designs premium quality 21×23.25×1 air filters that help to minimize the allergen levels in the indoor air while creating a clean, healthy environment. The filters prevent dust and debris from accumulating on the parts of your HVAC system.

Unlike other flat filters, our 21×23.25×1 filters are made with pleated media that provide a large surface area and a superior dust-holding capacity. Due to the greater surface area, our AC and furnace air filters trap and hold more than 90% of tiny particles, preventing them from inevitably settling on the surfaces in your home.

All of our air filters are manufactured in the USA with superior quality material. This will ensure you get the best quality products at the prices you love.

Custom Filters Direct recommends you check and replace your HVAC filters regularly. If you ignore replacing the dirty air filters regularly, they can increase the energy bill and may cause damage to the HVAC unit. So, we recommend replacing the air filters every 30 to 60 days.

We have MERV 8, MERV 11, and MERV 13 Filters


When looking to improve the indoor air quality of your home, MERV-8-rated air filters are an economical solution as these filters capture 85% of harmful contaminants 3 – 10 microns in size.


MERV 11 filters capture 85% of harmful allergens 3.0-10.0 microns in size and 50% of particles 1.0-3.0 microns in size. These filters are ideal for homes with pets, commercial spaces, schools, and more.


MERV 13 AC and furnace air filters capture more than 90% of harmful allergens 3.0-10.0 microns in size and 75% of particles 0.3-1.0 microns in size. These filters are designed for industrial buildings, hospitals, surgery units, and other places where superior air filtration is required.

21×23.25×1 Air filters Delivery Services

Enhance indoor air quality and extend the life of your HVAC unit with Custom Filters Direct. Our 21×23.25×1 air filters are manufactured in the USA so that you will get superior quality products at very reasonable prices. All of our filters are available in packs of 4, 6, 12, and more. You can use our auto filter delivery service plan which ensures your home will stay clean and healthy all year long. We also offer a one-time delivery option with special discounts. Place your order now!