heating, ventilating, and air-conditioning system

HVAC system) A mechanical system designed to satisfy the environmental conditions within an air-conditioned space, usually controlling the temperature, relative humidity, distribution and movement of air, and air cleanliness.
Types of systems differ, but a basic system often includes an outside-air intake, chiller, preheater, dehumidifier, heating coil, humidifier, fans, ductwork, air outlets, and air terminals.