Home air filters can help reduce indoor air pollutants and protect your health, but not all filters work the same way. When considering what type of air filter is best for your needs, it’s important to understand the different types, ratings, and maintenance requirements.

What Are Home Air Filters? 

Air filters are simple devices that you place in HVAC systems to prevent debris from being pushed into your home with the air that is distributed by your heating and cooling systems. Standalone appliances that treat air such as humidifiers, window air conditioning units, and air purifiers also have similar filters.

The Benefits of Air Filters for Your Health 


Air filters help prevent dust and debris, including dirt, pet fur, dander, cigarette smoke, and other allergens from circulating in your home. Using a clean air filter means you don't have to dust whenever you turn on your heat or air conditioning and reduces the irritation that allergens cause. People with allergies or asthma are especially susceptible, so adding an air purifier and changing the air filter in your HVAC system often can be helpful.

Air filters also help reduce substances from the air that contribute to lung cancer, including tobacco smoke and radon gas, and pull asbestos particles from the air.

In addition to these health benefits, air filters allow your home's HVAC system to work more efficiently by preventing debris from entering and damaging any mechanical parts.

Home Air Filter Types and Rating


Filters use a variety of materials and techniques to clean the air in your house. If your home has an HVAC system, it likely uses one of four filter types:

  • Flat-panel fiberglass filters protect your HVAC system more than your health. These filters are disposable.
  • Pleated media filters come in standard and high-efficiency options and remove more particles from the air than flat-panel filters. These filters are also single use.
  • High-efficiency air filters known as HEPA can catch up to 99.97% of particles but are more expensive than other types.
  • Washable filters remove particles from the air and are reusable. They may spread germs if replaced while still wet though.

Less common filters rely on activated charcoal filtering, UV light, or filtering via electric charge.

Regardless of the filter type, the filter has a square or rectangular frame that fits into the HVAC system or appliance, and will have a Minimum Efficiency Reporting Value (MERV) rating between 1 and 20. A higher rating indicates more effective air cleaning. A MERV rating between 13 and 16 is comparable to a HEPA filter, which catch particles as small as .3 microns, or 150 times smaller than a strand of hair.

While a system can be compatible with multiple filter types if it is the right size, always use filters with MERV ratings according to your system manual. Using an air filter that is rated too highly can damage your system.

What Maintenance Is Required for Home Air Filters?

Air filter maintenance involves washing or replacing the filter.


Check the manual for each appliance or system to find the filter location and directions for how to clean or replace the filter.

Once you have accessed your air filter, the next step is to clean or replace it.

To wash a dirty filter, spray it with a hose until the water runs clear. Let it air dry fully before replacing it. Replace the filter so that the arrow on the frame points into the system in the direction of airflow. You should also take this time to clean the vent if there is any visible dirt.

If you use your HVAC system regularly and have A typical one-inch filter, make sure to replace the filter monthly. The filter may not appear "full" or dirty, but this maintenance keeps your furnace running well and your air clean. Thicker, five-inch filters can be changed less often, about twice a year.

No matter the type, air filters clean the air in your home and require regular maintenance. Fortunately, this is simple and helps deliver the greatest health and mechanical benefits.

For more home maintenance and home health tips, click here to find a high trained WIN Home Inspector near you. Alternatively, call at (800) 309-6753 or email us at inquiry@wini.com and one of our experts will contact you promptly.