The two major types of HVAC systems are the residential ones and the commercial ones. Residential HVAC system as the name suggests are installed in homes and small businesses whereas commercial HVAC units are installed in larger spaces like office buildings, shopping malls and other large buildings. Both the units function to heat and cool a given space. What varies is the amount of power used, capacity, manufacture etc. There are companies that deal with both commercial as well as residential HVAC system while there are also companies that specialize in just one type. The main difference between a commercial and residential unit is its size. A commercial unit is much larger than residential unit moreover commercial ones are more complex. They have a more complicated thermostat. The amount of power consumed also differs in a commercial unit and due its larger size it will consume more energy.
The location where both the units are installed also differs. A residential unit is usually installed in the backyard while commercial units are placed on the roof of the building. There are a number of aspects to consider while installing a commercial unit like the number of rooms, how many people will be using the space, the type of business etc are a few of them. Since residential HVAC units are less complex some of its maintenance works can be done by the owner while commercial HVAC maintenance need to be done only by professionals. A commercial HVAC unit requires multiple drainage pipes and panels unlike a residential unit that requires only a single pan.