Quality Comfort Home Services Logo

The question of how often to change a furnace filter comes up a lot, especially during the spring and fall seasons. The answer truly depends on your living environment and the type of filter you have.  Here are some circumstances that will increase the frequency of which you need to change your filter, no matter what type of filter you have:

  1. Pets in the home

  2. Large number of people occupying the home

  3. Allergy sufferers in the home

  4. Those with respiratory ailments in the home

  5. The level of pollution/construction around the home

If you can relate to any of those 5 items, be sure to change your filter a bit more frequently than what is commonly recommended to help your home’s air stay healthier.

Other than the living environment, the frequency of which you change your filter also depends on what type of filter is in the home.

There are 3 main types of filters:

  1. Throw away or fiberglass filter (usually 1″)

  2. Pleated filter (size can vary)

  3. Media filter (usually 4-6″)

Typically for a fiberglass filter, you should be changing these out every month. As the name suggests you can simply throw away the other filter each month. These are the least expensive type of filter, but obviously also the weakest and most temporary type.

You can usually change a pleated filter about every 3 months. 

For a higher rated filter, like a media filter or 4”/5” pleated filter, we recommend every 4-6 months.

Besides the type of filter and your living environment there is one final factor that can affect how often to change your furnace filter – that is the MERV rating, or efficiency, of the filter.

To figure out the efficiency of your current filter you can look up the MERV rating. MERV stands for Minimum Efficiency Reporting Value and ranges from a score of 1 to 20. This tells you the size of particles an air filter is designed to clean out. A lower MERV rating means only larger particles are captured. A higher MERV rating means more (and smaller) particles are being filtered out. If your filter has a higher MERV rating then it can go a bit longer between changes. It is also imperative to keep in mind that these high efficiency filters can be restrictive to your HVAC system since it has to work harder to force air through the filter. The highest MERV rating is not always the best for your home.

Lower MERV ratings are less efficient to catch particles but do allow more air to go through your filter, which can improve the operation of your HVAC system.

In summary, the four areas you should take into consideration in deciding how often to change a furnace filter are:

  • Your living environment
  • Personal health needs of home occupants
  • Type of filter
  • MERV rating of filter

Outside of air filters, there are other air quality solutions to help maintain healthy air in your home. Those include media air cleaners, UV lights, air purifiers & more. We always offer free estimates on any of these items.

If you have questions about which air filter might be right for your home HVAC system, please feel free to give us a call at 513-620-4822.