A VAV terminal unit, often called a VAV box, is a zone air flow control device. It is basically a quality, calibrated air damper with an automatic actuator. The VAV terminal unit is connected to either a local or a central control system which changes the damper
position pending on the demand from the thermostat or sensor. Historically, pneumatic control was commonplace, but electronic direct digital control systems are popular especially for mid-to-large size applications.
- A common commercial application for a VAV system consists of a VAV box with damper, ductwork, and registers.
- VAV boxes are supplied air from large air conditioning unit’s indoor fans. These types of systems are normally seen in large office buildings and malls.
- Little maintenance is required for a VAV box, bi-annual testing is recommended prior to summer and winter seasons.
As we like to say, “Preventative maintenance doesn’t cost… It pays!”