All filters are made in the USA  – Order Today


Premium Filters
Protects all against
Protects all against

21x21x1A – Merv 11

21x21x1A – Merv 11
AC Furnace Air Filter
Rated 0.0 out of 5
0.0 out of 5 stars (based on 0 reviews)

Select Filter Quality

Total Price
Price per filter $0
Quantity Price Per Filter
1 $0.00
2 $0.00
3 $0.00
4-5 $0.00
6-11 $0.00
12+ $0.00

Product Description

Filter Size: 21x21x1A

Actual Size: 21x21x1

Actual Size Fraction : 21x21x1

Customer Reviews

Rated 0.0 out of 5
0.0 out of 5 stars (based on 0 reviews)
5 Star0%
4 Star0%
3 Star0%
2 Star0%
1 Star0%

Review this product

Share your thoughts with other customers

Top Reviews

There are no reviews yet. Be the first one to write one.

Buy 21x21x1A Air Filters Online

A properly functioning air filter is a must for any home. If you have allergies or asthma, you may be especially sensitive to the buildup of dirt and bacteria that can be caused by a dirty filter, as well as the fumes that come with it. If you’re looking for ways to keep your house cleaner without breaking the bank, choose Custom Filters Direct 21x21x1A air filters.

Our air filters are not only made with the HVAC industry standards in mind but they are also built with strong construction which makes them last longer than ordinary filters available in the market.

These air filters ensure you always breathe clean and healthy air while reducing the hazards associated with allergens build-up in ductworks, no matter how harsh the environment in your home. They not only remove the unwanted allergens but also promote superior indoor air quality on your premises.

All of our AC and furnace air filters are manufactured in the USA in our own factory. So, you will get a cost-effective solution when you need high-efficiency filters for your home, office, or industrial building. Designed with charged synthetic media, these filters are proven to have a higher dirt-holding capacity and long-lasting filtration.

When uses for a longer period, the air filters get dirty. The dirty air filters will slow down the airflow and make your HVAC unit work harder to heat or cool your home. We recommend you check and replace your air filters every 2 to 3 months. The more frequently will you change your air filters, the more efficient it is, leading to energy savings. It also helps to prolong the life of the HVAC system.

Choose the Right MERV Air Filter


These AC and furnace air filters are a cost-effective way to improve indoor air quality. MERV 8 filters capture 85% of common airborne contaminants 3-10 microns in size. These filters will keep your home free of pollen, lint, dust mites, and more.


These air filters are designed to effectively capture and block more than 85% of air pollutants from your residential and commercial environment. MERV 11 filters will eliminate pet dander, mold spores, dirt, debris, smog, smoke, and more.


These air filters improve clean airflow and eliminate more than 90% of unwanted particles from your residential, commercial, and industrial environment. MERV 13 filters offer the highest protection against allergens and have the capacity to capture the smallest particles in the air.

21x21x1A Air Filters Delivery Services

Custom Filters Direct is the name you can count on when looking to buy the best quality 21x21x1A air filters online. We offer an auto-delivery subscription service that will remind you to check and change the old filter at regular intervals. You can also choose the one-time delivery option and get huge savings on bulk orders. Place your order now!