Furnace Filters

Why is a furnace air filter important?

The air filter cleans air that passes through your heating & cooling system before it is pumped throughout your house. Furnace filters also filter air from central air conditioners. Filters help with home ventilation and can reduce or eliminate common allergens, dust and other impurities so you can enjoy cleaner air.
 

How often should you change your furnace air filter?

This depends on the size of your home, whether you have pets and the air quality where you live. A good rule of thumb is to replace filters every 3 months. You can also visually inspect your filter every 30 days and replace it if it looks dirty. If you have washable furnace filters, regular inspection will let you know when it’s time to clean them.

What does the MPR of an air filter mean?

The MPR rating refers to the filter’s ability to capture particles from the air. The higher the rating the better.

What size furnace air filter do I need?

Popular sizes include 16x20x1-in, 20x20x1-in, 16x25x1-in and 20x25x1-in, but be sure to check your furnace instruction manual or measure a dirty filter to find out what size you need. Some reusable filters come in a large size that can be cut to fit many different types of furnaces.
 

What features should I look for in a furnace air filter?

You will want to make sure that the filter fits your furnace and that its filtration level is what you need. Allergen-specific filters can make your home much more comfortable, especially during allergy season. A reusable filter can be a good investment to save money over time, though they do require regular cleaning to be effective.
 

What happens if you put a furnace filter in backward?

It all depends on the filter type. Some furnace filters, such as reusable and washable ones, work in either orientation. Other types of filters usually have clear markings on the sides, so you know you are installing it correctly.