The definition of HVAC operation is the process of controlling the temperature, humidity, and air quality of a building or space. This is done through the use of heating, ventilation, and air conditioning (HVAC) systems. HVAC systems are designed to provide a comfortable environment for occupants by controlling the temperature, humidity, and air quality of the space. HVAC systems can be used to cool, heat, humidify, dehumidify, and filter the air. HVAC systems can also be used to improve indoor air quality by controlling the amount of pollutants in the air. Proper HVAC operation is essential for providing a comfortable and healthy environment for occupants. Proper HVAC operation requires regular maintenance and inspection to ensure that the system is functioning properly and that all components are in good working order. Proper HVAC operation also requires the use of energy efficient systems to reduce energy costs and improve the overall efficiency of the system.