Many years ago I found a decommissioned school bus & transformed it into a home. I initially had a window cooling system on the old bus to keep it cooled down but I could only use the window cooling system whenever I was near a power source. When I heard about new solar window cooling systems & other solar Heating, Ventilation plus A/C units I suddenly drove to a nearby cooling & heating supply shop & purchased myself a new solar window cooling system; Now I could use this cooling system component to keep my house/bus cool all afternoon. As the years passed I decided I wanted to build a central cooling system for my house/bus so that both the front & back could be the same temperature. I did some reading on zone controlled Heating, Ventilation plus A/C & figured it would do the job in a school bus with simply a central cooling system that had air ducts on the front & in the back. I rented a small garage that I used as an Heating, Ventilation plus A/C shop while I constructed the central cooling system for my bus. I was lucky to find someone who wanted to purchase my old window cooling system for more than I originally got it from the cooling & heating business. I use the currency from the new solar window cooling system to purchase heating & cooling component for my very sleek and modern central cooling system. My last step in building the cooling system was to purchase HEPA air filters & put them inside the air ducts of the central cooling system. These new air filters will ensure that my bus has enjoyable indoor air pollen levels & that my SEER rating stays great.