• Share:
The Best Furnace Filters to Buy

A high-efficiency furnace filter can slow airflow too much, but low-efficiency filters don't filter dust very well. Get a better understanding of the issues and learn how to find the right filter for your furnace.

By the DIY experts of The Family Handyman Magazine

The Best Furnace Filters to Buy

A high-efficiency furnace filter can slow airflow too much, but low-efficiency filters don't filter dust very well. Get a better understanding of the issues and learn how to find the right filter for your furnace.

Choosing the right filter for your furnace

The choice of which filter to buy for your furnace depends on how much you want to spend, what you're trying to filter, and how diligent you are about changing the filter.

The minimum efficiency reporting value (MERV) scale goes from 1 to 16. Most residential filters range from 4 to 12. Furnace manufacturers prefer the traditional spun fiberglass filters (MERV 2) because they filter out enough of the large particles to protect the furnace while providing maximum airflow. Maintaining the furnace manufacturer's specified airflow is critical to achieving energy efficiency and maximum life from the blower motor and heat exchanger. An inexpensive MERV 4 filter captures 80 percent of the particles 50 microns and larger, but only 25 percent of the particles in the 3 to 10 micron range.

For most homeowners, a more expensive MERV 7 or 8 pleated filter provides a good balance between cost and filtration efficiency. These filters trap 80 to 95 percent of the particles 5 microns and larger—more than enough filtration for most households.

Furnace efficiency is one thing. But if you're a clean freak or have family members with allergies or low-immunity issues, spend more on a high-efficiency (MERV 11 and higher) filter. Then just make sure you stay on top of filter changes to protect your furnace.

High-efficiency filters capture 99 percent of airborne particles as small as 0.3 microns (bacteria and viruses, fumes and pollen). But you'll have to run your furnace fan full time to get the maximum benefit from a high-efficiency filter, and that will cost more. Figure the extra cost into your decision.

Finally, never switch from a fiberglass filter to a high-efficiency filter without first talking to your HVAC technician. The technician can boost fan speed to compensate for the reduced airflow. Even then, you still have to be diligent about replacing the filter regularly. A clogged filter can burn out the blower motor, damage the heat exchanger and cost you hundreds of dollars in wasted energy.

Back to Top

Comments from DIY Community Members

Share what's on your mind and see what other DIYers are thinking about.

1 - 3 of 3 comments
Show per page: 20   All

February 22, 7:02 AM [GMT -5]

No doubt it is very informative to read. I really persuade others to look your furnace maintenance. Filters are very important to replace on time. I have quality high efficiency for good home heating system.
Thanks

February 03, 9:54 PM [GMT -5]

I was hoping you would rate/discuss the washable filters on the market and whether they are a good value.

January 21, 12:55 PM [GMT -5]

Thank you very much for this very helpful information on the proper use of air filters. I was not aware of the importance of using the proper type of air filter. I have been considering having a professional come look at my furnace so that it is up to snuff for the long cold winter, but I'm not sure who I should call. Has anyone heard of Airtron ? If so, would you recommend them? Thanks for your input!

+ Add Your Comment
closeX

Add Your Comment

The Best Furnace Filters to Buy

Please add your comment
closeX

Log in to My Account

Log in to enjoy membership benefits from The Family Handyman.

  • Forgot your password?
Don’t have an account yet?

Sign up today for FREE and become part of The Family Handyman community of DIYers.

Member benefits:

  • Get a FREE Traditional Bookcase Project Plan
  • Sign up for FREE DIY newsletters
  • Save projects to your project binder
  • Ask and answer questions in our DIY Forums
  • Share comments on DIY Projects and more!
Join Us Today
closeX

Report Abuse

Subject
Reasons for reporting post

Free OnSite Newsletter

Get timely DIY projects for your home and yard, plus a dream project for your wish list!

Follow Us

Featured Product

Buy Now