Aaron - Ours does the same thing - any time there is a 12 volt
drain (lights, fantastic fans, bath/shower vents, battery charge, radio, etc.) the power inverter is working and the fan cools it. Fridge is either propane or AC current and shouldn't cause this. Be sure not to block those vent louvers!
What color scheme did you get on your DDC? We have the orange and LOVE it! Visitors to our trailer in various parks are envious!
Have you towed it anywhere yet?
Best of luck -