Commercial air conditioning systems and heaters are, of course, much larger than conventional residential AC units. Otherwise, there are not many differences between commercial systems and residential systems; they all run on refrigerant and use coils and blower fans to remove heat and cool a space.
However, there is typically a difference in the way air conditioners are installed on commercial buildings and the way they are installed in homes. A rooftop packaged HVAC unit is the best choice for many commercial properties (though not all). This type of AC and heating system sits on the rooftop of the building, and it tends to be the best choice for many of the commercial air conditioners and heaters in our area.