A commercial HVAC (heating, ventilating, and air cooling) system has the same function as a residential HVAC system. The idea is to maintain the environment during a chilly night or a 72-degree hot summer day. Overall, the system's principle is the same, however, it is a more robust version of residential HVAC, capable of supporting large complexes. The heating is achieved by burning fuel like gas, oil, or electricity, and the cooling is achieved by a natural process where hot indoor air is extracted and cooled using a refrigerant or water colling system. Ventilation is provided by suction fans and filters.