fridge temp difference AC vs. GAS

[agate]

When I am running my Dometic 3-way on gas, the temps can get very cold. I like that. When I am home and plug it in, the temps do not get nearly as cold? Why is that do you suppose? Each time the temp selection is set on "5" the highest setting. Id say 5 is the real deal on gas and about a 1 or 2 at best when plugged in. Still cold enough to keep veggies etc... but I like my beverages colder than that.

Anyone have these experiences?

 

[MarkBC]

I think this is why:
In 3-way (gas-absorption) fridges, what the propane or the electricity do is to heat the refrigerant fluid. But the propane does it by a burning flame and the electicity does it with an electrical resistance heater. The propane flame just works better (at heating the fluid) than the relatively-wimpy electrical heater.
For practical purposes, a 3-way is really a one-way (propane). At least, that's been my experience.

Here's a diagram of a generic 2-way (propane or electric) gas-absorption refrigerant system. It's pretty complicated...even though I'm a chemical engineer and should understand this well I'd have to spend some time to really figure it out . The point is, though, that at the lower right of the diagram it shows schematically the burner and an electrical element, and either one or the other is used to heat that vertical tube.

 

[agate]

That is what I suspected, althouh you summed up what my wife and I were thinking. A little sun on the camper mid-day and that addis to the heating. Thanks.

--mike