2020-07-04 00:00:00 The duct size is calculated from the air flow rate by the equal friction loss method (equal pressure method or constant pressure method). The constant pressure method (equal friction loss method or equal pressure method) determines the duct dimensions by using the same value for friction loss per 1 m of all ducts. On the setting screen, you can change the temperature, humidity, and atmospheric pressure of the air passing through the duct, change the material of the duct, or change the unit.