EPA Recommended Air Cleaners

Type of Air Cleaners

• Mechanical and electronic air cleaners remove particles, such as dust, pollen and animal dander from the air. Mechanical cleaners remove particles by capturing them in a filter. Electronic cleaners remove particles from the air by sending ions to attach to the particles. These ions give the particles a charge, which causes them to attach to nearby surfaces. Gas-phase air filters remove gasses and odors from the air, such as sulfur dioxide and cigarette smoke, by absorbing them with a material called a sorbent. Ultraviolet germicidal irradiation cleaners, photocatalytic oxidation cleaners, and ozone generators remove indoor air pollutants, such as germs and bacteria, by exposing them to ultraviolet radiation.

  An air cleaner can be a part of a building's heating, ventilation and air-conditioning unit or can be a portable, stand-alone unit.

Standards

• The Institute of Environmental Sciences and Technology, IEST, sets the standards for comparing the performance of different types of air filters. They use four different tests when determining a filter's efficiency: the weight arrestance test, which evaluates the ability of low-efficiency filters to remove larger particles from the air; the atmospheric dust spot efficiency test, which rates the ability of a medium-efficiency cleaner's capability to remove fine particles from the air; the DOP penetration test, which determines the percentage of particles removed by true high efficiency particulate air, or HEPA, filters; and the PSE test, which uses increasing amounts of synthetic dust to provide a composite minimum efficiency for each type of filter.

Warning

• The EPA warns that some cleaners, such as ozone generators, are not effective enough to be beneficial and can emit by-products, such as ozone, a lung irritant.

Recommended Cleaners

• To remove the most particles from the air, the EPA recommends using high-efficiency particulate air filters. Because of the density of the filter, HEPA filters are not usually installed into a building's HVAC. To remove the most particles from the air, the EPA recommends a stand-alone cleaner in addition to a medium-efficiency filter installed in the building's ventilation system. Bag and box filters can also remove a high number of airborne particles.

  Due to their inefficiency and by-products, the EPA warns against the use of ozone generators or cleaners that target indoor air pollutants.