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The Difference Between Allergen & HEPA Filtration

Indoor air pollution presents problems for homeowners, commercial buildings and any other indoor facility. Filtration systems clean indoor air of contaminants and other harmful substances. Allergen and HEPA filtration systems offer two means of purifying the air. The difference between the two involves the types and amounts of particles the systems remove.

  1. Mechanical

    • According to the Environmental Protection Agency (EPA), both allergen and HEPA filters belong to a class of filters designated as mechanical. They capture airborne contaminants by trapping the particles in the filter material. One drawback to both types is that many particles, particularly small ones, settle on the ground quickly and never reach the filtration system. Most large particles are removed by both systems. The difference lies in the efficiency of the filtration.

    Definitions

    • Allergens refer to any particle or substance that causes allergies in humans. Examples include pollen, dust, animal dander, dust, smoke and gases from appliances and household products like cleaners. An allergen filtration system is any filter system that is not a HEPA system. High-efficiency particulate air, or HEPA, represents the ultimate in air filtration. A true HEPA system is only used in commercial settings such as hospital rooms, burn centers and laboratories, according to the Environmental Doctor. Many products are sold as HEPA filtration, but they do not approach the high standards of the true system.

    Efficiency

    • The EPA outlines the rating system for mechanical filtration systems. The rating system is known as minimum efficiency reporting value, or MERV. The system rates systems from a low of 1 to a high of 20. The filters normally used in residential heating and air conditioning systems range from 1 to 4. They are used to protect the equipment, not keep the air clean. Allergen filtration with ratings of 7 through 13 are likely to come close to HEPA filters in removing particles, according to the EPA. Filters rated from 14 to 16 are often labeled as HEPA. True HEPA filters range from 17 to 20 and can remove up to 99.97 percent of all particles from the air.

    Choices

    • When choosing between an allergen and HEPA filter, check the MERV rating. The number tells you how efficient the system is at removing unwanted particles. Anything other than the numbers do not explain the difference.

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