High Efficiency Particle Arrestor filters are replaceable extended-media dry-type filters that remove a minimum particle collective efficiency of 99.97 percent for a 0.3-micron particle. (Some HEPA filters remove up to 99.9997% of such particles)

Filters with a minimum efficiency of 99.97% for 0.3µm particle size as determined by test. The test can be by the monodispersed dioctyl phthalate (DOP) method or other equally sensitive method. When operated at design velocity, larger and smaller particles are captured at higher efficiencies. HEPA filters are made of compressed and bonded micro-fiberglass or Teflon® corrugated to produce a high surface area in a small area panel of filter medium. Employed in unidirectional airflow benches, air handlers, and as terminal air supply filters in cleanrooms.

This acronym stands for high efficiency particulate air filter.

special filters that can be used in ventilation systems to help remove droplet nuclei from the air

High Efficiency Particulates Air Filter Units characterized by having particle efficiencies better than 99.97% for 0.3 micron particles and larger. Go to top

High efficiency particulate air filters are replaceable extended-media dry-type filters in a rigid frame having a minimum particle collective efficiency of 99.97 percent for a 0.3 micron particle, and a maximum clean filter pressure drop of 2.54 cm (1") water gauge when tested at rated air flow capacity.