Price-HVAC
Supplier of Preference for Air Distribution
Terminal Unit Sizing – Inlet Valves
May 10, 2011 by PriceHVAC
All variable air volume (VAV) terminal units—including single duct, bypass, system powered induction, fan-powered or dual duct—have a common function: regulate the amount of primary air entering the terminal unit.
This control of the primary air volume can be used for the following purposes:
- Occupied space temperature regulation
- Discharge air pressure regulation
- Discharge air temperature regulation
- Mixing of primary air with return air in an induction terminal
The primary air valve assembly contains an inlet tube, damper and air flow sensor. When sizing a terminal unit inlet, HVAC designers aim to minimize the sound generation of the terminal unit, as well accurately resolve the flow signal at both full and minimum cooling.
