I drove the ambulance to one of the largest ambulance dealers in the US yesterday. They regularly remount (new truck, rebuilt ambulance module) ambulances, and their customers nearly always want new air conditioning. They had just removed the 120 VAC air conditioning unit (a Hoseline unit) from a module they were rebuilding, and I was able to buy it for a whale of a lot less than new.
It will have a front-of-module condenser, a compressor probably mounted under the module, and a dual evaporator to handle both the engine AC, and the 120 VAC AC. It needs a control module to get the two systems to cooperate with each other, and an 80 amp 12 volt supply to run the condenser fans and the AC blower. The end result is about 12,000 BTU.
That will make it more humane for me to work in the module in the summer, and I can also plug 'er in somewhere else. A 4000 watt generator is also in the works - I've looked at both the Onan Emerald series and the new Microquiet generators. The Emeralds are an older design that are fairly bulky (and are no longer made), but only 1800 RPM, while the Microquiet units are 3600 RPM units that are probably both half the size, and half the weight. I've always leaned towards an 1800 RPM unit, but then I realized that virtually every generator Onan sells for RVs is 3600 RPM (gasoline & propane). I can only assume that the design of modern engines is a lot more sophisticated than the old B&S or Kohlers that I remember from only 30 years or so ago. I haven't seen any postings of engine problems - the most common problem seems to be a control card.
The old Emeralds use the same engine I remember fighting with in an arc welder many many moons ago, so I have a bit of prejudice against them - but I'm starting to think that the new Microquiets might be the way to go. I still have months to figure it all out, but the Micros might win out.
Tune in tomorrow....
In other news:
I finally have a handle on the beast's heating system. As near as I can tell, it has a hot water circulating pump that comes on with the AC/HEAT switch, and that pump also supplies the cab's heating system. I'd always thought that the AC/HEAT switch was just for the module, but then I saw that it can be on with the module being off (based on the pilot light). When it's on, I have plenty of cab heat -- when it's off, no cab heat. EUREKA!