Many years ago I purchased a university school bus to transform into a home. I initially had a window mounted air conditioner unit on the bus to keep it cool however I could only use the window mounted air conditioner unit when I was by power source. When I heard about solar window mounted air conditioner units plus other solar HVAC units I abruptly went to a nearby cooling plus heating tech plus purchased a solar window mounted air conditioner; Now I could use this air conditioner component to keep our bus cool all through the afternoon. As the years passed I decided I wanted to build a central air conditioner for the bus so that both the front plus back could be the same temperature. I did some research on zone controlled HVAC systems plus figured it would work in a university bus with only a central air conditioner that had air ducts on the front plus back. I rented a small mechanic’s garage that I used as an HVAC shop while I built the central air conditioner for the bus. I was lucky to find someone who wanted to purchase our window mounted air conditioner for more than I originally bought it from the cooling plus heating tech. I use the currency from the solar window mounted air conditioner to purchase heating plus cooling equipment for our modern central air conditioner. My last step in building the air conditioner was to get air filters plus put them inside the air ducts of the central air conditioner. These HEPA air filters will ensure that our bus has fine air quality plus that our SEER rating was excellent.