Furnace-filters - Free Shipping & Returns

Select your filter’s thickness:

1” or 2”

3” or more

Why finding the right thickness of filter is important.

Ensuring that your filter fits properly in your HVAC system means making sure that you have not only the right length and width, but also thickness of your filter. Most standard air filters are 1 - 2 inches in thickness. Whereas media filters are typically 3 to 5 inches in thickness. The best way to measure your air filter size is to get out the measuring tape and measure it directly.

Regularly replacing your air filter will help improve the efficiency and longevity of your furnace.

A dirty filter in your HVAC system will raise your energy bills. A dirty filter restricts the air flow into your HVAC systems air handler, causing it to work harder to cool or heat your home.

A dirty clogged filter can restrict HVAC airflow and potentially cause problems with the system. They also cease to filter allergens and other particulates out of your air.

Dirty, unchanged filters can make your HVAC system fail completely. Repairing a broken HVAC system can end up costing you a pretty penny.

...or find your filter by brand

  • Aprilaire Air Filters
  • 3M Filtrete Air Filters
  • Trion Air Bear Air Filters
  • American Standard Air Filters
  • Carrier Air Filters
  • Honeywell Filters
  • Bryant Air Filters
  • Goodman Air Filters
  • Trane Air Filters
  • GeneralAire Air Filters
  • Lennox Air Filters
  • Space-Gard Air Filters
  • Skuttle Media Filters
  • White Rodgers Air Filters
  • Dynamic Air Cleaner Refills

Breathe easy with DiscountFilters.com - we have the best selection of discount furnace filter replacements at the best prices on the web. We carry all of the top OEM and aftermarket filter models in a variety of sizes and MERV ratings. We have the right discount furnace filters for whatever you need - including custom filters for hard-to-find sizes.

Did you know that the air inside your home is up to five times dirtier than the outside air? Indoor air can be contaminated with dust; allergens like pollen, dust mites, and pet dander; mold; and other impurities. A good furnace filter is electrostatically charged to capture these impurities, protecting your home and your family from odors, bacteria and germs, and other respiratory irritants. If you or anyone in your home suffers from allergies or asthma, air filters for your furnace are especially important.

A good furnace filter not only protects the health of your family - furnace filters were originally designed to pick up dirt and dust from being sucked into your furnace, air conditioner, or HVAC unit. When these particulates enter your HVAC system, they burn up and leave carbon deposits and residue on the heating elements and inside the ventilation system. This residue makes your system less efficient and results in additional wear and tear on your system, leading to costly repairs and shortens the life of your furnace or air conditioning system.

Protect your home, your HVAC system, and your family with a high-quality furnace filter. DiscountFilters.com has the best selection of discount air filters, including custom filters, at the best prices on the web. 

We Love Filters

Save Your Furnace Tip #8:

If you have a 6-month filter, schedule your filter changes when daylight savings changes. When you "spring forward" or "fall back" setting clocks around the house, change your filter at the same time.