My '75 Argosy has a square screened opening in the bottom of the refrigerator cabinet, I'm assuming as a source of cooling and combustion air (the locker door for that compartment is not vented.) Since the belly pan is beneath that, it's protected from splashes and such, and between the volume of the belly pan area and the fact that it's not all that tightly sealed I guess it's sufficient.
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill