Check out a Norcold manual. The preset temps for the already installed vent fans are much much higher. We spent summer 2018 in N Mex and with the sun, our frig could not stay cool enough. We added a computer fan at the bottom of the exterior access blowing upward helping the hot air to move up and out thru the roof venting. After making this alteration, we were able to keep the frig at a good temp. Now that cold weather has arrived we have shut that fan off as you do need some heat for the frig to function properly and in extreme cold may even need to partially block the opening so that there is enough heat.