Many years ago I purchased a school bus and transformed it into a home. I initially had a window air conditioner on the bus to keep it cool but I could only use the window air conditioner when I was by power source. When I heard about solar window air conditioners and other solar HVAC units I quickly went to a nearby cooling and heating business and purchased a solar window air conditioner. Now I could use this a/c unit to keep my bus cool all day. As the years passed I decided I wanted to build a central air conditioner for my bus so that both the front and back could be the same temperature. I did some research on zone controlled HVAC and figured it would work in a school bus with simply a central air conditioner that had air ducts on the front and back. I rented a small garage that I used as an HVAC shop while I built the central air conditioner for my bus. I was lucky to find someone who wanted to purchase my window air conditioner for more than I originally bought it from the cooling and heating business. I use the money from the solar window air conditioner to purchase heating and cooling equipment for my new central air conditioner. My last step in building the a/cunit was to purchase air filters and put them inside the air ducts of the central air conditioner. These air filters will ensure that my bus has good indoor air quality and that my SEER rating was great.