HMS HVAC stands for Heating, Ventilation, and Air Conditioning. It is a system that is used to control the temperature, humidity, and air quality of a building or space. The system is made up of several components, including a furnace, air conditioner, air handler, thermostat, and ductwork. The furnace is responsible for providing heat to the space, while the air conditioner cools it down. The air handler is responsible for circulating air throughout the space, while the thermostat is used to control the temperature. The ductwork is used to distribute the air throughout the space. By using these components, the system is able to provide a comfortable and safe environment for occupants.