High Efficiency Air Filtration devices manufactured under the trademark HEAF are used to control emissions from sources where fabric filters cannot be used because they plug up with sticky or viscous particulate materials, where wet scrubber require excessive energy consumption because of extremely small size distribution of the particulate matter, or where electrostatic precipitators cannot be used, because the particulate matter fouls the collection plates and causes shorting between the electrodes.

HEAF devices are manufactured in four different types. These units are Mini HEAF, the Stationary Drum HEAF, the Flat Bed HEAF and the Rotary Drum HEAF.

The Mini HEAF is used for small air pollution sources and uses a manually changed cartridge filter for the capture of air pollutants. The stationary Drum HEAF is used only for a pressurized gas stream where a fully automatic operation is required. The Flat Bed HEAF uses roll type filters for moderate gas flows and fully automatic in operation. The Rotary Drum HEAF unit is a fully automatic filter used for individual emission control applications up to 210100 m3/hr (125000 acfm) in a single unit.