Only as a point of reference (and related specifically to a truck camper)...
Lance specs an Onan 2.5 kW propane generator as their standard on board generator when purchased as a factory option.
Lance provides two different air conditioners as factory installed options from which to choose. One is a 9K BTU model and the other is an 11K BTU model. While these are sized to provide relief inside the small volume found in a truck camper, neither unit would be adequate for a mid-range TT, let alone a FW.
This thread did get me thinking about running air off a genny so I checked the specs on the Onan 2500 and learned that;
1. Power output decreases 1% for every 10 degrees of ambient air temperature above 77F.
2. Power output decreases 3.5% for every 1,000 feet above a baseline of 500 feet.
Cowboy math approximates that one would lose about 9% of output at 97 degrees and 2500 feet of elevation.
Onan also warrants that the 2.5kW propane unit will start and run one 13,500 Btu high efficiency air conditioner plus a 600 watt base load with no additional watts of power available...provided one is at/below 77F and 500 feet of elevation.
Fuel consumption is rated at 0.3 gal/h at no load; 0.4 gal/h at half load and 0.6 gal/h at full load.
Oh yeah...125 pounds!!!
