18 x 24 x 1 Filtrete Ultimate Allergen Reduction Filter - UA21DC-6

3M UA21DC-6 | Our#: 174852
6 pack

18 x 24 x 1 Filtrete® Advanced Allergen Reduction Filter from 3M - # UA21DC-6. 3M Performance Rating = 1900 . Highest performance for Filtrete 1" filters.

  • MERV 12 Rated
  • Change Every 3 Months
  • 18x24x1" Nominal
  • 17¾x23¾x⅞" Actual
$125.94 $163.99
Case of 6 Filters, $20.99 ea
In Stock
Ships Tomorrow, Dec. 17th
Est. Delivery By Dec. 24th

18" x 24" X 1"  Filtrete® Ultimate Allergen Reduction Filter from 3M - # UA21DC - 6 Pack

The Filtrete® Ultra Allergen Reduction Filter carries a 3M Microparticle Performance Rating (MPR) of 1900 - roughly equivalent to a MERV 12 rating


  • Meets the American Lung Association® Health House® Indoor Air Quality Guidelines
  • No unnecessary antimicrobial chemicals added; Filtrete filtering material will not support the growth of bacteria, mold, mildew or fungi in normal use
  • Contains electrostatically charged media to filter and attract particles in the air

93% effective at capturing large allergens like:

  • Pollen
  • Mold spores 
  • Dust mite debris

Attracts and captures microscopic allergens like:

  • Smoke
  • Pet dander
  • Household dust
  • Smog
  • Bacteria
  • Particles that carry viruses
  • Particles that can carry odors

* This filter should be changed at least every 3 months.  Certain conditions in your home will significantly add particles to the air - this will cause the filter to capture more particles, shortening it's life to less than 3 months.  These conditions would include: dirty ductwork, pets, construction work, sanding projects, tobacco smoke, burning candles, fireplaces and wood-burning stoves.


The  Heating, Ventilating and Air Conditioning (HVAC) industry uses the ASHRAE 52.2 Standard, which assigns a Minimum Efficiency Reporting Value (MERV) to a filter. One part of MERV reports a filter's ability to capture medium to large particles between 1 and 10 microns. This value is helpful in comparing the performance of different filters but it is not adequate alone because particles greater than one micron make up only about 1% of the contaminants in your indoor air.

Another part of MERV addresses submicron particles. 3M calls this the MPR or Microparticle Performance Rating. It measures a filter's ability to capture particles between 0.3 and 1.0 micron. Based on independent laboratory tests, 3M's MPR measures a filter's ability to capture submicron particles that make up 99% of the particles in the air, such as bacteria, smoke and smog.


by PowerReviews
3M18 x 24 x 1 Filtrete Ultimate Allergen Reduction Filter - UA21DC-6

(based on 1 review)

Reviewed by 1 customer

Displaying review 1

Back to top

(0 of 1 customers found this review helpful)


Bad odor from the filters.

By none

from Vicksburg, MS

About Me Professional

Verified Buyer


  • Filters Particles Great


  • Odor From Filters
  • Odor From Filters-chemica

Best Uses

  • Central AC

Comments about 3M 18 x 24 x 1 Filtrete Ultimate Allergen Reduction Filter - UA21DC-6:

The filters are emiting an odor-of either a chemical of metalic-type-something that is used in the filter. While it does a great job of filtering particles - its composition is emitting an odor that I have never experienced in 16 years, or form any other filters I have used.

Displaying review 1

Back to top