• Spend $70 or more and your order ships free! We'll get your filters out the door fast so you can enjoy clean air and water.*

    * Orders under $70 ship for $5.99.

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  • Every order is carefully packed and shipped by our team in Indiana. Your purchase helps support American jobs and hardworking families right here in the Midwest. Our AIRx Furnace / AC Filters and ClearChoice Fridge Filters are made in the USA.

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  • Spend $70 or more and your order ships free! We'll get your filters out the door fast so you can enjoy clean air and water.*

    * Orders under $70 ship for $5.99.

  • Shop with confidence! If you're not completely satisfied with your purchase, you have up to one year to return it for a refund or exchange. We stand behind every filter we sell.

    Learn More

  • Every order is carefully packed and shipped by our team in Indiana. Your purchase helps support American jobs and hardworking families right here in the Midwest. Our AIRx Furnace / AC Filters and ClearChoice Fridge Filters are made in the USA.

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We don't know what's in your water,
but we know there's nothing in your cart.

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21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack

5
73 reviews
◆
 
Average rating 4.5/5
5 stars
(52)
4 stars
(13)
3 stars
(4)
2 stars
(2)
1 star
(2)
AIRx 21.5x23.5x1-ALLERGYOur#: 194970
Made in USA
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
21.5x23.5x1 AIRx ALLERGY Air Filter, 4-Pack
Compatibility guarantee — Wrong fit or not happy - we'll make it right, up to a whole year
Change every 3 months
Change every 3 months Swap on schedule for best performance
Made with pride in Greenwood, Indiana
Made with pride in Greenwood, Indiana Your purchase supports American jobs
MERV
MERV Find your ideal filtration level
Compatibility guarantee
Compatibility guarantee Wrong fit or not happy - we'll make it right, up to a whole year

Filter Description

If you want to promote superior air quality in your home, this is the air filter for you! The specialized media in the filter attracts and captures small particles that can cause allergies. We carry your size of air conditioner filter or furnace filter. We offer convenient online ordering and quick shipping right to your door!
Pleated media provides extended surface area for filtration, and low resistance to airflow
MERV 11 rating means the filter attracts household allergens like dust, pollen, mold spores, dander, smoke and smog
Replace every 90 days under normal use
Made with pride in the USA
100% free returns on all filters

$71.88

$89.85
Code DF20 · Save 20%
$17.97 per filter
Code DF20 · Save 20%
SAVE 0% 4-pack
In Stock, Ships onMonday, Oct. 5th
Only $70.00 more for free shipping! Add this — just more for free shipping! Buy this and your order ships free!

Orders over $70 ship free. $5.99 otherwise.

Your Order Ships Free!

Compare Side-by-Side

MERV Filter Comparison

Choose the filtration level that fits your home — then tap Select to update your cart above.

MERV 8
Standard
DUST
RECOMMENDED
MERV 11
Superior
ALLERGY
OPTIMAL
MERV 13
Optimal
HEALTH
Best For
STANDARD
Residential / Commercial
Healthy Families
SUPERIOR
Residential / Commercial
Allergy Sufferers
OPTIMAL
Residential / Commercial
Premium Protection
Comparable
Ratings		 MPR 600 & FPR 5 MPR 1000–1200 & FPR 7 MPR 1500–1900 & FPR 10
Filtration Captures ≥90% of large particles Captures ≥95% of large particles Captures ≥98% of large particles
Dust, Lint & Debris
Mold, Pollen
Dander, Dust Mites
Smoke & Smog
Bacteria
Odor, VOCs
Your
Filter
MERV 8
Standard
DUST
Best For Residential / Commercial, Healthy Families
Comparable MPR 600 & FPR 5
Filtration Captures ≥90% of large particles
Dust, Lint & Debris
Mold, Pollen
Dander, Dust Mites
Smoke & Smog
Bacteria
Odor, VOCs
RECOMMENDED
MERV 11
Superior
ALLERGY
Best For Residential / Commercial, Allergy Sufferers
Comparable MPR 1000–1200 & FPR 7
Filtration Captures ≥95% of large particles
Dust, Lint & Debris
Mold, Pollen
Dander, Dust Mites
Smoke & Smog
Bacteria
Odor, VOCs
OPTIMAL
MERV 13
Optimal
HEALTH
Best For Residential / Commercial, Premium Protection
Comparable MPR 1500–1900 & FPR 10
Filtration Captures ≥98% of large particles
Dust, Lint & Debris
Mold, Pollen
Dander, Dust Mites
Smoke & Smog
Bacteria
Odor, VOCs

Swipe or use arrows · tap to select

MERV (Minimum Efficiency Reporting Value) is an ASHRAE industry standard for measuring air filter efficiency.

Compatibility guarantee

Wrong fit, leak, or just doesn’t work? We’ll send the right one. Free return shipping for all orders.

365-day satisfaction

Not happy? Send it back any time in the first year — we’ll make it right. Yes, even an open pack you’ve been running for months.

No-hassle returns

No restocking fees, no return-merch authorization mazes — just start a return and our helpful Customer Experience team will assist.

Filter Maintenance

Is it time to change your Filter?

Generally, we recommend you replace your air filters every 90 days. Find out below if you should change your filters more often.

If someone in your home has asthma or allergies change your filter every

6 Weeks

to ensure indoor air quality is at its best.

If you have pets change your filter every

2 Months

to avoid shedding and odor buildup.

If you have young children change your filter every

2–3 Months

as having clean air is even more important with children in your home.

Filter Specifications

What does this filter remove?

Filtration capabilities
Nominal Size
21 ½ × 23 ½ × 1"
Actual Size
21 ½ × 23 ½ × ⅞"
Filter Media
Electrostatically charged 100% synthetic gradient media that does not support microbiological growth
Filter Support Grid
30 gauge galvanized expanded metal grid
Frame
Moisture resistant double-wall beverage board
Max Temperature
180F (82C) continuous service, peak 225F (107C)
Max Humidity
Resistant to 100% R.H.
Initial Resistance
0.18" WC
Rated Velocity
295 FPM

Performance Testing

Replaces These Filters

Bryant / Carrier

KFAFK0412XXL

National Filter Sales

PF-02-21.5x23.5x01-6

About This Product

Is this the right air filter for you?

If you want to promote superior air quality in your home, this is the air filter for you!   The specialized media in the filter attracts and captures small particles that can cause allergies.   We carry your size of air conditioner filter or furnace filter.  We offer convenient online ordering and quick shipping right to your door!

  • Pleated media provides extended surface area for filtration, and low resistance to airflow
  • MERV 11 rating means the filter attracts household allergens like dust, pollen, mold spores, dander, smoke and smog
  • Replace every 90 days under normal use
  • Made with pride in the USA
  • 100% free returns on all filters

Customer Reviews

4.5 4.5 out of 5 stars
73 verified reviews
5★
(52)
4★
(13)
3★
(4)
2★
(2)
1★
(2)
5
4.5 / 5 (73)
JONATHAN K. 8 days ago
5
Only manufacturer I found that offers odd sizes. Fits perfectly ?
Greg P. 290 days ago
5
I don't have the knowledge to compare filters, but we've been ordering from Discount filters for a bunch of years now. We are happy customers.
Myra C. 702 days ago
5
Love this product. Bern using it for years. It does what it’s supposed to do. Easy to install. Great value.
Vernon H. 974 days ago
5
The customer service is great and th we quality of the filters is very good
JONATHAN K. 1013 days ago
5
Happy to find a filter supplier for such an odd shaped one. Home Depot and Costco didn't have it. Great value and timely shipment!
Helene R. 1028 days ago
5
Excellent quality and great value for the money
Myra C. 1088 days ago
5
I have been using these filters for years and couldn’t be happier
Terry E. 1124 days ago
5
fits perfect
Christopher K. 1128 days ago
5
Great site, competitive price, good delivery and perfect communication.
Richard V. 1295 days ago
5
Great product
Lily 1323 days ago
5
My filters are an unusual size, hard to find in retail stores but thanks to discount filters I always have a supply on hand they’re of excellent quality and great price.
Larry M. 1707 days ago
5
Exact fit.
Raymond P. 2197 days ago
5
So far, the only thing we can say, : shipping was accurate and fast, staff very friendly. Experience of material will come with time :-)
George H. 2200 days ago
5
This filter size Lowe’s or Home Depot do not carry. Found it here and the prices were better than similar size filters at HD and Lowe’s, but not the right size. They were delivered quickly with no hassle. Very Good!
Edmund M. 2423 days ago
5
Does a great job pulling dirt, dust and debris from the air.
Sharon S. 2487 days ago
4
What I expect for a A/C filter, however I feel it's a bit expensive.
Ron M. 2629 days ago
4
Works well. Great response from customer service
kenneth j. 2634 days ago
5
If it wasn't for the discount from discount filters, I wouldn't have bought them.they are too expensive.
Daryl C. 2908 days ago
4
I have ordered this product before and it "gets the job done". However, I will NOT be ordering thru this company again. I can get the same filters at the same price on Amazon (without delivery and tax). They are supposed to be a "Discount ..." filter co. and I don't feel that they are.
Vernon H. 2985 days ago
5
It is very easy to order and have delivered. These filters are perfect for my use with the A/C. Much more convenient yhan running to the Lowes or Home Depot .
Dale C. 3069 days ago
5
Superior product, right size for our system, priced better than local suppliers and great Service from Discount Filters. I've recommended to others and will continue to do so.
Dale C. 3485 days ago
5
Thus far, no negative issues. Very pleased with our purchase. Will use again.
Greg P. 3512 days ago
5
Found the service to be fantastic, and the filters work great. Dust is noticeably reduced and the air seems healthier. Great price as well.
Charles R. 3528 days ago
5
The air in the house is a lot cleaner and smells fresher, I don't see dust floating in the like my old filter.
Nick K. 3716 days ago
5
I have used the product for many years and found it to be an effective filter medium
Rachel M. 3724 days ago
5
This was my first time ordering with Discount Filters. My filters came quickly and they fit perfectly. My filter size is not found at my local hardware stores, so this works great! Will definitely be ordering again.
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