Question on Running Onan onboard Gen on hot days

Toy hauler fifth wheel. I didn’t run it, but am finding it is taking forever the the two 15000 btu AC’s to catch up. My infrared heat gun show it almost all areas of the camper over 100° when we parked. Two hours later high 90s. I finally open the turbo cool in both bedroom and in the garage which eliminated the duct system. Hoping to cool those down first and pull the heat out and will then work on the main living compartment as it gets cooler tonight