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Air Furnace AC Filters

How to replace a furnace filter

Air filters for the home on sale at Filter Outpost. 


Save with our Filter 6-packs. Most filters are bundled into 4-packs or 6-packs so the price you see is the price for all 6. (except washable filters and other singles)

You will notice there are a wide range of filter options and prices. The filters that cost more tend to capture smaller particles and more particles in general.

Find filters by width (shorter side):
10 inch     11 -13 inch     14-15 inch     16-17 inch     18-19 inch     20 inch     21-23 inch     24+ inch

High efficiency electrostatic filters filter the air but also attract contaminants magnetically. They are good for filtering out smoke, bacteria, pollen, mold spores, dander and more.

If you are not as concerned with capturing smaller particles, or are concerned with higher airflow efficiency in your furnace, then you could go for the lower priced pleated filters. These tend to need changing every 3 months or so. Cheap filters are disposable fiberglass, but they don't stop pollen and mold.

The Pleated Filters and ElectroStatic filters are better for trapping particles, dust and dirt. 

A higher MERV (Minimum Efficiency Reporting Value) rating on a scale from 1-11+ means the filter is more efficient at removing small particles. Learn more about air filters on our filter guide page.

When replacing furnace air filters, be sure that the arrow is facing the direction of air flow. See the video for tips on replacing your furnace filter. 


To change your furnace filter, remove the old one and discard it in a trash bin with a lid. Have the new filter ready (make sure you check the size before ordering - is written on the side of the filter.)

Push the new filter back in with the arrow on the filter edge pointing TOWARDS the blower motor. If you install it incorrectly, it will decrease the filter's efficiency. See the video for tips on replacing your furnace filter. 

Get Filtrete and other top name brand filters at online discount prices through Filters Outpost USA.


Links found in the Air Filters section are currently pointing to off-site affiliate companies that offer great prices on air filters.  We will be stocking filters in the near future. For now, we are providing these links as a service to find nice quality air filters online at great prices.