<p>These terminal units, commonly referred to as VAV boxes, are<strong> </strong>used to control the volume and, sometimes, the temperature of air entering a designated space. There are a few different types of terminal units used in today's developments: single duct, parallel fan-powered, and series fan-powered. plenum air inlet , control valve , hot water coil , union , round duct for cold supply air inlet , hot water coil associated piping and fitting apply to heating and cooling terminal only , support rods from roof structure with vibration isolation A VAV terminal unit, often called a VAV box, is<strong> </strong>the zone-level flow control device. It is basically a calibrated air damper with an automatic actuator. The VAV terminal unit is connected to either a local or a central control system. for more details download this file.</p> <p> </p> <p> </p>