96/04259 How much air mixing is enough?

Abstract

The three charts presented in this article are intended to provide the HVAC system designer with a method that can be used to select the type of mixing system needed for each particular HVAC system. These charts are based on an economizer control strategy wherein 100% outside air is introduced into a system when the outside air temperature is equal to the mixed air temperature set point. As the outside air temperature drops below this set point, the control dampers reduce the amount of outside air to maintain the desired mixed air temperature.