What is the definition of a VFD HVAC? A Variable Frequency Drive (VFD) HVAC system is an advanced type of air conditioning system that uses a variable frequency drive to control the operation of the air conditioning system. This type of system is often used in commercial and industrial buildings due to its energy efficiency and cost savings. The term VFD stands for Variable Frequency Drive and is a type of motor control device that can control the speed, torque and direction of an electric motor. VFDs are used to control the speed of the motor, which in turn helps to regulate the flow of air from the air conditioning system. The VFD HVAC system is designed to save energy by adjusting the speed of the motor according to the temperature set by the user. This allows the user to more effectively control the flow of air in the building, which can result in significant energy savings. Additionally, the VFD HVAC system is designed to reduce the noise levels in the building