Many years ago I purchased a retired school bus plus transformed it into my home.
I initially used a window bracketed air conditioner on the bus to keep it cool but I could only use the window bracketed air conditioner when I was nearby a power source.
When I heard about using solar power for window air conditioners plus other solar HVAC units I suddenly went to a local cooling plus heating supplier plus bought a solar powered window air conditioner! Now I could use this air conditioner unit to keep our bus cool all day. As the years passed by I decided I wanted to build a central air conditioner for our bus so that both the front end plus the back could be the same temperature. I did some research on zone controlled HVAC systems plus figured it would work in a school bus with a simple central air conditioner that had air ducts on the front plus back. I rented a small local garage that I used as an HVAC shop while I built the central air conditioner for our bus. I was so fortunate to find someone who wanted to purchase our window air conditioner for almost what I originally obtained it from the cooling plus heating business. I use the currency I save from the solar window air conditioner to purchase heating plus cooling units for our up-to-date central air conditioner. My last step in building the air conditioner was to purchase the best air filters plus put them inside the air ducts of the central air conditioner. These great air filters will ensure that our bus has great air quality plus that our SEER rating was terrific.