The definition of a HVAC VAV<VAV (Variable Air Volume) system is a type of heating, ventilation, and air conditioning (HVAC) system that uses a single, central air handler to control the temperature and air quality of a building. It is designed to provide the right amount of air at the right temperature and humidity levels to keep occupants comfortable. The system works by using a series of dampers and fans to regulate the air flow and temperature in each room. The dampers are used to control the amount of air that is released into the room, while the fans help to distribute the air evenly throughout the space. The system also uses sensors to monitor the temperature and humidity levels in the room and adjust the air flow accordingly. HVAC VAV systems are often used in commercial buildings, such as office buildings, hospitals, and schools, as they provide a more efficient and cost-effective way to maintain comfortable temperatures and air quality.