The official business definition of VAV Unit HVAC is a type of air conditioning system that is designed to provide variable amounts of heated and cooled air, depending on the demand within a given space. It typically comprises a main air handler and several smaller units located throughout the premises, each providing heated or cooled air into the occupant spaces as required. This system can help reduce energy consumption by ensuring that only the amount of air necessary to satisfy comfort requirements is supplied, thereby helping to improve energy efficiency overall.