• 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.

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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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18x24x1 AIRx ALLERGY Air Filter, 4-Pack

5
77 reviews
◆
 
Average rating 4.6/5
5 stars
(65)
4 stars
(3)
3 stars
(4)
2 stars
(1)
1 star
(4)
AIRx 18x24x1-ALLERGYOur#: 194762
Made in USA
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 AIRx ALLERGY Air Filter, 4-Pack
18x24x1 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

$64.78

$80.98
Code DF20 · Save 20%
$16.20 per filter
Code DF20 · Save 20%
SAVE 40% 4-pack

Pack Size

Filtration Level

Compare all →
In Stock, Ships onTuesday, Sep. 29th
You're $70.00 away from free shipping! Buy this and you're only from 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
18 × 24 × 1"
Actual Size
17 ½ × 23 ½ × ¾"
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

Performance Rating

MERV (µm) PSE (%) 0.3-1.0 1.0-3.0 3.0-10 Airflow Rate (CFM) 443 664 885 1106 885 * * Max Rated Airflow
11 29 68 86 Initial Resistance (IWC) 0.09 0.13 0.19 0.25 0.19 *
MERV
11
(µm) PSE (%)
0.3-1.0 29
1.0-3.0 68
3.0-10 86
Airflow Rate (CFM) Initial Resistance (IWC)
443 0.09
664 0.13
885 0.19
1106 0.25
885 * 0.19 *
* Max Rated Airflow

Replaces These Filter

National Filter Sales

PF-02-182401-6

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

4.6 4.6 out of 5 stars
77 verified reviews
5★
(65)
4★
(3)
3★
(4)
2★
(1)
1★
(4)
5
4.6 / 5 (77)
Minda S. 33 days ago
5
This company had excellent customer service.
Ed 695 days ago
5
Needed special size filters. These arrived quickly and work very well.
James S. 734 days ago
5
Excellent quality, always a perfect fit. Super convenient to order.
Lrdvdrss 734 days ago
5
Can not believe how much it would cost elsewhere.
Bruce H. 768 days ago
5
Well constructed filters that fit as advertised and are performing well to date.
anthony p. 776 days ago
5
works goods
Bonnie F. 1115 days ago
5
I accidentally ordered the wrong size. (And then reordered the correct size when I discovered my error.) Customer Service was amazing and immediately refunded these. Thank you! It is so encouraging to discover such good will toward your customers! Very refreshing!
Robert G. 1127 days ago
5
Great value
Jan O. 1129 days ago
5
Excellent price. Fast shipping
Patricia B. 1256 days ago
5
They work and they're affordable. Shipment was expedient. I love Discount Filters!!!
Rick P. 1363 days ago
5
Quality quantity and price! Also having them on hand
Clifford K. 1580 days ago
5
Easy to order on line, always a great product that does the job.
Kenneth F. 1625 days ago
5
Good service
Jim E. 1652 days ago
5
great deal
Janice A. 1670 days ago
5
Love the 3 month filters
Mirna F. 1757 days ago
5
Good product!
Paul B. 1849 days ago
5
No review
Bernard S. 1861 days ago
4
Overall, the quality was equal to the price paid. These filters were less cost than my locally purchased filters. As such, they appeared to be less in quality as well. My biggest disappointment was the smaller filter size. Their overall advertised dimensions of 18x25x4 turned out to be smaller in each dimension. These filters fit very loose in my filter frame holder, where my prior 18x25x4 filters (actual dimensions) fit perfect, filling the entire filter frame. I prefer a proper fit filter for my furnace/AC unit.
RICHARD L. 1870 days ago
5
Filters are very good. Fair prices. Boxes were crushed during shipping. Filters are still usable. Better shipping boxes are needed.
Scott W. 1906 days ago
5
I received what I ordered in a very timely manner. Good value.
wtanders2891730 1917 days ago
5
We've been using this provider and product for for several years and like both. The Filters take the particles out of the air. The provider gives fast & accurate service.
Linda P. 1993 days ago
5
Great value great service
DEORTUBE/CONSUELO S. 2026 days ago
5
Fast delivery
Jorge M. 2030 days ago
5
Easy to order - very fast delivery... LOVE that they are MADE in the USA !!!
Madeleine L. 2210 days ago
5
Love these filters!
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