One thing I have noticed when it comes to the 2 types of commercial heating plus s, is that one os more powerful than the other. I am speaking of the difference between rooftop Heating plus Air Conditioning systems plus your basic commercial heating plus s. With rooftop heating plus s, you get more power for some reason. At least that’s what it feels like. It seems that in every commercial building I have been in that had a rooftop heating plus , it was much more cooler or warmer (depending on the time of year). While in buildings that had official commercial heating plus s, it was nice, but not as powerful. I am speaking of course as a general consumer. I am not a company owner nor do I work in a building that has a rooftop heating, ventilation plus A/C method to compare to. The office I work in has official commercial heating, ventilation plus A/C. This is what I am comparing it to. I may very do some more research into this on my own time because I am seriously curious if it is just me, or if what I assume is really correct, and never the less, my opinion on the matter sticks as rooftop commercial heating plus s are the best occasion of choice to go with if you are going to set out to heat plus cool a commercial building. If you have a smaller building, then of course your basic central heating, ventilation plus A/C method would work just great as it would in a apartment or small store.