A HVAC system is a heating, ventilation, and air conditioning system that is used to regulate the temperature, humidity, and air quality in a building. The system is made up of several components, including an air handler, ductwork, and a thermostat. The air handler is responsible for circulating air throughout the building, while the ductwork distributes the air to the different rooms. The thermostat is used to control the temperature of the air. HVAC systems are used in both residential and commercial buildings to provide a comfortable environment for occupants. They are also used to help reduce energy costs by controlling the temperature and humidity levels in the building. HVAC systems are designed to be energy efficient and cost effective, making them a great choice for any building.