Air Filters Buying Guide

Pick the best air filters for your home

High-efficiency air filters are a cost-effective way to help improve indoor air quality, which may be beneficial to family members sensitive to allergens and other particles in the air.

Air filters helps to keep your furnace’s coils and heat exchangers clean, which may prolong furnace life and keep it running efficiently. 

Replace your air filters four to six times a year for cleaner air and a healthier HVAC system.

This guide will help you understand The Home Depot’s Air Filter Performance Rating system so you can easily choose the air filter that best fits your needs.

The Home Depot Air Filter Performance Rating (FPR) System


The Home Depot Air Filter Performance Rating System (FPR) ranks all brands of filters The Home Depot sells by measuring their ability to capture large and small particles. It also factors in the weight gain caused by the filtration process over the filter’s lifetime. 

The FPR creates a weighted average for each filter, which is then ranked on a 1-10 scale: 1 being the lowest performance, and 10 being the highest performance air filter. 

Sixty percent of the rating is determined by the filter's ability to capture large particles, thirty percent is determined by its ability to capture small particles, and weight gain over the filter's lifetime determines the final ten percent.

Premium Air Filters: FPR 10

  • Large particles like household dust, lint, dust mites, pollen and pet dander
  • Small particles like bacteria and mold spores
  • Smoke, smog, microscopic allergens plus particles that can carry viruses
  • Particles that carry odors


Best Air Filters: FPR 9

  • Large particles like household dust, lint, dust mites, pollen and pet dander
  • Small particles like bacteria and mold spores
  • Smoke, smog, microscopic allergens plus particles that can carry viruses


Better Air Filters: FPR 7

  • Large particles like household dust, lint, dust mites, pollen and pet dander
  • Small particles like bacteria and mold spores


Good Air Filters: FPR 4

  • Large particles like household dust, lint, dust mites, pollen and pet dander 


In addition to the filter's strength, the FPR also indicates which type of airborne contaminants each filter is ideally suited to capture.

air filter contaminants
Contaminants Captured by these FPR Ratings:


Dust/Lint
Pet dander
Dust mite
Pollen

FPR 10, 9, 7, 4


Bacteria
Mold

Tip: Use electrostatically charged air filters for best filtration of these contaminants.

FPR 10, 9, 7


Microscopic allergens
Smog
Smoke
Virus carriers

Tip: Use electrostatically charged air filters for best filtration of these contaminants.

FPR 10, 9


Odor 

Tip: Use electrostatically charged air filters for best filtration of these contaminants.

FPR 10


Filter Types


Fiberglass, polyester, washable, pleated and electrostatic filters each offer different air filtering capabilities. Electrostatic filters provide the highest level of filtration for small particles. 

Tip: While most filters are disposable, some may be cleaned with water or by vacuum. An advantage of disposable filters is you’re not exposed to the trapped contaminants during cleaning.

Filter Type Benefits

Fiberglass or Polyester

  • Inexpensive
  • Disposable
  • Good for capturing large particles like lint and dust

Washable/Reusable

  • Can be cleaned and reused
  • Require replacement only every few years
  • Protect furnace motor and trap larger particles

Pleated

  • Disposable
  • Larger surface area captures more particles

Electrostatic

  • Disposable or reusable options
  • Charged fibers help to capture small and large particle


Air filter Size and Installation


Filters are sized in two ways: nominal and actual. Nominal is the approximate size of the filter, rounded up to the nearest inch. Actual is the filter’s exact size. 

In addition to standard height and width dimensions, air filters also vary by thickness. They can be less than one inch thick, or up to six inches thick.

The most popular air filter sizes are listed below, sorted by width x height x depth in inches.


Getting an exact fit is crucial to having an effective air filter - the wrong size won't fit and will cause the filter to stop working properly . To ensure you get the right fit, take your current air filter out and check the size printed on the frame.

Installation Tips:

  • When inserting your air filter, make sure it fits snugly in the chamber. Loose filters may let air pass around the filter instead of through it.
  • Make sure your filter is sturdy. The frame should be strong enough to withstand pressure caused by the air that moves through it. Check the frame after installation to see if it is intact and that the joints are secure.