High efficiency particulate air (HEPA), originally called high-efficiency particulate absorber/arresting/arrestance, is a type of air filter. The filters must satisfy certain standards of efficiency set by the United States Department of Energy (DOE). These filters can be used in medical facilities, automobiles, aircraft and homes.

Standard requirements: The air filter must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 µm.

Ventilation systems are used in conjunction with the HEPA filtration systems to achieve a high standard or air quality for the area they service. These specialised systems which work together to maintain strict pressure ratings and are highly durable to avoid any duct leakages. Hospitals, clean rooms and pharmaceutical manufacturing sites are some of the places which need this type of ventilation system. These ventilation systems need to be severely pressure and quality tested.