The 4 Types of HVAC Air Filters

HVAC filters remove impurities from the air and help keep indoor air clean. During allergy season, it is especially important to make sure HVAC filters are clean and able to continue removing pollen, dander, dust and other allergens from the air.

How Air Filters Are Rated

Filters are rated using a system called MERV, which stands for Minimum Efficiency Reporting Value. The MERV system has a rating range of one to 16.

Filters in the MERV range one through four can remove pollen, dust mites, standing dust, spray paint dust and carpet fibers. The next level, five through eight, can remove mold spores, hairspray, cement dust and fabric protector. Filters rated nine through 12 can remove humidifier dust, lead dust, auto emissions and milled flour. The highest range, 13 through 16, can remove bacteria, most tobacco smoke and droplet nuclei (from a sneeze).

Home HVAC Air Filters

There are four types of HVAC air filters and each one is uniquely different.

Flat-paneled fiberglass filters

Flat paneled filters are the least expensive type of filter and, as expected, the least efficient. This type of filter removes dirt, pollen, pet hair and lint but is unable to filter out smaller contaminant particles. Flat panel filters made of synthetic material are denser and more efficient. This is the most common type of HVAC air filter used in homes.

Pleated media filter

A pleated filter has a MERV rating between five and 13 and is able to remove more contaminants because it is pleated like an accordian. Its greater surface area and density helps trap smaller particles of pollen and pet dander as well as mold spores. Pleated media filters last longer and are made of a synthetic material or a cotton-polyester blend.

Reusable air filter

Reusable air filters can be washed and don’t need to be completely replaced. These air filters have a MERV rating between one and four and can attract mold and mildew growth if installed before they are completely dry. Washable filters offer low efficiency and become dirty pretty quickly.

HEPA filter

HEPA filters have a MERV rating between 17 and 20 and are the most recommended type of HVAC filter. They can trap tobacco smoke and bacteria and offer homeowners the greatest health benefits. To install a HEPA filter, a contractor will need to make modifications to the HVAC system.

If you notice your home’s air quality is not what it used to be, reach out to Hamilton Plumbing Heating A/C Rooter to have your HVAC filter replaced.