TO-98-21-2 -- Mixing Box Damper Testing PDF

To meet the controlled ventilation requirements proposed for the revision of ANSI/ASHRAE Standard 62-1989, it is important that the correct type of damper be selected to accurately provide and maintain the volume of air required in the mixed air plenum. Testing of the dampers commonly used in manufactured air-handling units has shown that the mixed air dampers can drastically affect the intake ventilation air and the overall performance of the air-conditioning system. Therefore, selecting the correct blade action can improve the variability to achieve the correct ventilation air quantity. This paper focuses on testing and recommends the blade action to be used on manufactured air-handling units.

Units: I-P