Ac power is much more efficient as a power source for the frig. The frig will get colder faster and stay colder when on AC power.
If you leave the frig on 112vdc power you will work the converter harder. The energy expended to convert the 110vac to 12vdc will be released as heat. The converter cooling fan will come on more often sending this heat into the TM via the vents on the front of the power center in the hallway. At some point the 12vdc circuits (lights, fans, 12vdc TV, etc.) will start loading the converter down and your frig will get even more inefficient (warmer).
MJL
Ah, it all makes sense to me now :-). Thanks for the education Mike!
Sally