HT pleat filters are designed as a pre filter operating at high temperatures up to 500ºF/260ºC, with low pressure drop and long service life. Filters are classified with MERV8/G4/EU4 efficiency. They are made with a pleat distribution of 13 pleats per linear foot and are recommended to operate up to 2000 ft³/min. Filter face area can be custom made in many dimensions and the maximum recommended pressure drop is 1.2 inWg/300 Pa.