So, like Evan, we use Gen/AC A LOT.

In medium-sized Mono with a 6-7kW Generator you're likely to consume about 0.25-0.35 gal/hr while simultaneously running the AC and charging batteries.

We run the generator about 12-14 hours a day, so that's somewhere around 90 hours a week, consuming about 25-30 gallons of Diesel. At $2.50 a gallon that's about $75/week for everyone to sleep well for a week. Cheap.

On a larger cat (we just got off CYOA's Cuvee, 50-foot cat with 6 air conditioners) you might consume 0.5-0.6 gal/hour running most/all the AC units, watermaker, and charging batteries.