Furnace Filters

Furnace Filters Profile:

Why You Should Replace Your Furnace Filter

The key to creating a healthy environment in your home or business is regularly changing your furnace filter. Furnace filters not only prevent airborne contaminants like dust, pollen, mold spores, bacteria, and other allergens from getting into your air, they will also increase the efficiency and longevity of your furnace, reduce energy costs, and improve airflow.

Furnace filters, air filters, AC filters, HVAC filters— no matter what you call them are all the same. FiltersFast.com is your one-stop shop to buy furnace filters online.

What Size Furnace Filter Do You Need?

When it comes to furnace filters, size is of the utmost importance. There is no “one size fits all” for furnace filters. Filters come in different lengths, widths, and depths. Making sure you have the correct size air filter is so important. Why? Installing the incorrect size furnace filter can cause harmful contaminants to get into your air. It can also cause dust and dirt to build up on your furnace’s coils which can lead to costly cleaning and repairs.

Where are furnace filters located?

Furnace filters are typically installed in or near your furnace. Depending on the design of your house or building, you will find your air return located in the wall, ceiling, and sometimes in the floor. Typically, you will have a return for each level of your home or business.

How to Measure Furnace Filters

Your furnace filter’s size is usually printed along the side of your existing furnace filter. If your filter doesn’t have the size printed on the side, you can measure the filter yourself to find out what size filter you need. When you measure your filter, you will usually find that these measurements include ¼ and ¾ measurements which is called the actual measurement. When shopping for furnace filters, you will usually see nominal measurements listed. Round up the actual measurement of your filter to find the right nominal size of your furnace filter.

What is a MERV Rating?

After figuring out what size furnace filter you need, the next step is to select the MERV rating you need. MERV stands for Minimum Efficiency Reporting Value. MERV is the industry standard set by the American Society of Heating, Refrigeration and Air Conditioner Engineers that rates the overall performance of a filter. Sometimes you might see a rating other than MERV listed, like FPR or MPR. You can learn more about the differences in the ratings on The Filtered Files Blog. The higher the MERV rating, the more airborne particles it will capture. We recommend MERV 11 for residential application.

Not sure what MERV rating you should use? Check out our MERV Rating Chart.

When Should You Replace Your Furnace Filter?

It’s recommended that you change your furnace filter every 1-3 months for maximum efficiency. Wish there was an easier way to remember what size filter you need and when it needs to be changed? Sign up for our Home Filter Club Furnace Filter Subscription! Simply select the frequency you’d like your filters delivered at and change it when they arrive!