The definition of a Building HVACHVAC (Heating, Ventilation, and Air Conditioning) system is a set of mechanical systems that work together to provide thermal comfort and indoor air quality in a building. HVAC systems are designed to maintain a comfortable indoor environment by controlling temperature, humidity, air flow, and air quality. They can also be used to reduce energy costs by controlling the amount of energy used to heat and cool the building. HVAC systems are made up of several components, including air handlers, ductwork, fans, chillers, boilers, and other equipment. The components are connected to each other to form a complete system. The air handlers are responsible for providing fresh air to the building, while the ductwork is used to transport the air throughout the building. The fans and chillers are used to move the air and control the temperature. The boilers are used to heat the air, while the other equipment is used to filter and purify the air. HVAC systems are essential for providing a comfortable and healthy indoor environment, and they can also help to reduce energy costs.