HVAC (Heating, Ventilation, and Air Conditioning) systems are designed to provide thermal comfort and indoor air quality in buildings. They are composed of several components, such as air handlers, fans, and ductwork, that work together to regulate the temperature and humidity of the air. Chiller systems, on the other hand, are designed to cool water or other fluids. They are composed of a compressor, condenser, evaporator, and expansion valve, and use a refrigerant to transfer heat from the fluid to the atmosphere. While both systems are used to regulate temperature, HVAC systems are used to regulate air temperature, while chillers are used to regulate fluid temperature.