Gimpy, I would consider it, but where would I mount it? No trailers.
Mike, those things are true. One issue is how to cool the condenser.
About the controls, I do not like the modern electronic controls on the a/c units today. They tend to encourage less comfortable settings and if the power goes off and comes back, the a/c is not going to turn itself back on.
The vertical units usually cool at the back panel and fit flush with the outside of the enclosure, and the more common horizontal units cool themselves on the sides and back, and are made to stick out of the enclosure. I don't want anything to stick out. I do not mind cutting openings to facilitate condenser cooling.
A condenser needs an air in and out. A possibility is to sacrifice one window to perform one side of this. With an M109, it is possible to go through the floor for this, or through the side. I am still thinking of ways to avoid cutting the walls. A 12x18 grille in the floor, under a piece of machinery, that is OK, no one will notice.
In TX, a minimum of 12,000BTU is needed in an S-280 to achieve 70 degrees inside with 100 degrees outside and direct sun. Possibly more in an M109
Over 4 years of doing coms at an annual event I have this small set of data:
conditions: 100 +/-3 degrees, July, 60% humidity, full sunlight.
shelter: S-280 in M35 bed. No cover. Outer skin 120 degrees
Inside conditions:
8000 BTU: inside skin 100 degrees, inside air 80 degrees
12000 BTU: inside skin not measured. inside air 70 degrees.
18000 BTU: inside skin 90 degrees, inside air 65 degrees
So... me being a cold fiend, I am looking at maintaining a high capacity, more than a ton. Ideally, two small units can be installed so that one can be used alone when two are not needed. That is how I had the M35's S280 staged. First the 8000, then the 12,000.
As it's a 5-ton truck, I don't care about weight except that it is well distributed from one side to the other. It needs some weight in the back. I am open to different configurations, and I like vertical units because that is the kind of room in an M109.