The USP supply breath for restaurants, schools, flats, offices, etc. Key Elements Airtime: It varies from 50 to 800 m./h or 15 250 l/s. Supply: The element is supplied with circular duct connection that is under temperature 10C below the room breath temperature. Utility: USP is utilized for 1 way or 4 way pattern spread. Sizes: Available in 5 unit sizes of 100 to 250.