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21x21x1 – Merv 11

21x21x1 – Merv 11
AC Furnace Air Filter
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Product Description

Filter Size: 21x21x1

Actual Size: 20.5×20.5×1

Actual Size Fraction : 20-1/2×20-1/2×1

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Shop 21x21x1 Air Filters Online

Unfortunately, a number of pollutants can easily make their way into the indoor space, and these can have a variety of negative effects on the health of your family. This is why it’s important to invest in quality air filters like Custom Filters Direct 21x21x1 air filters. By removing contaminants from the air, you can help to protect your family against a number of potential health issues. Plus, using our air filters will help to keep your home smelling fresh and clean, which is always a good thing.

These filters are designed with the latest technology which makes our AC and furnace filters very efficient, durable, and long-lasting. Built with pleated media, these air filters provide a great surface area and reduced pressure drop. They are ideal to use in almost any environment, like residential, commercial buildings, surgery units, hospitals, manufacturing facilities, LEED green buildings, and other applications where superior air filtration is required.

One of the most important things to remember when it comes to air filters is that you should clean out your air filters regularly to remove any build-up of dirt or debris. This will improve the performance of your HVAC unit, keep your home’s air clean and healthy and protect you and your family from respiratory illnesses.

Choose the Right MERV Air Filter


These AC and furnace air filters easily capture particles like dust, pet dander, dust mites, mold, and many other airborne allergens 3.0 to 10.0 microns in size.


These air filters are designed to greatly improve clean airflow in both commercial and residential environments by eliminating more than 85% of annoying particles ranging in size from 3.0 to 10.0 microns and 50% of particles ranging in size from 1.0 to 3.0 microns.


These HVAC air filters have the capacity to eliminate more than 90% of particulates ranging in size from 3.0-10.0 microns and up to 75% of particles ranging between 0.3-3.0.

21x21x1 Air Filters Delivery Service

How often you should change your air filters depends on certain factors, mainly on the level of pollution around your home. We recommend you change your air filters once every 2 to 3 months. Replacing the air filters is easy when you choose the Custom Filters Direct subscription service. You only need to select the number of filters you need and the time interval between the deliveries. We will send you a pack of 21x21x1 air filters at regular intervals. We also offer a one-time delivery option to try our air filters. We offer huge discounts on bulk orders. So, place your order now!