I use a small dorm-sized 120V fridge in my trailer. When 120V shore power is not available, it is powered by a Xantrex 1000W inverter. Power is supplied by 300AH of battery capacity and a single 235W solar panel. The small fridge draws 80W, when operating (considerably more during instantaneous LRD, when starting) In a typical MN Summer,it operates at a 1/4 duty cycle. The compressor draw is about average for 120V fridges, I've found. An owner can calculate draw from the yellow "smart tag" on the new appliance.
I have eliminated the vents that were in the fridge compartment. My small fridge has the cooling fins on the sides and there is no big build up of heat since it resides in an open area underneath a kitchen counter top. Depending on how tight the enclosure is around the fridge, you may wish to leave some passive venting. I'd leave the roof vent since they are difficult to either eliminate or block and heat rises.
My fridge is plugged into the standard duplex receptacle behind it when on shore power or is plugged directly into the inverter when on inverted power.
Everyone's battery bank(s) are different as are vehicle specific trailer charge values. The largest part of operating a fridge from 12V inverted power is having enough battery bank so it will last until sunshine is on the solar panel. For some, that is overnight. For others, it may involve days of bad weather. First step is knowing what the fridge draws.
