Refrigerator Cooling, Propane vs. Electric

[k9dad]

Question about refrigerator cooling during preparation for a trip. Does it cool faster when plugged into electric (in my driveway) or just leaving the propane on and cooling that way?
Thanks for any input.

[wa8yxm]

k9dad wrote:
Question about refrigerator cooling during preparation for a trip. Does it cool faster when plugged into electric (in my driveway) or just leaving the propane on and cooling that way?
Thanks for any input.

The answer is ... Sometimes.

Ideally the fridge should cool at exactly the same speed on either Gas or Electric but in practice it is very hard to balance the two systems that close.. So one (and the only way to tell which is with a thermometer and a stop watch) will be faster.

Though the difference may be a good race. (that is 23 hours on one and 22:50 on the other kind of race).

[DrewE]

Jim@HiTek wrote:
If you turn it off whenever you return from a trip, you'll likely get 7 to 10 years of useful life so I always leave mine plugged in and on all the time. The pluses for leaving it plugged in and running continuously (it's ready to go when you are!) far outweigh the minimal power usage. Your batteries are always ready too.

As far as which method cools fastest? Never saw a much of a difference those few times I had to shut it off. But my gut feeling is for my Dometic, gas was faster. Slightly. My Norcold? Seems faster with electric. I'd tend to agree that there's not enough difference to be concerned.

That "minimal power usage" of an RV fridge is somewhere in the rough vicinity of 2000 kWh per year, or perhaps $400 for the year depending on your electric rate. Maybe that's minimal to some people, but it's more than enough for me to shut it off when not in use and start it up (or do without) before taking a trip.

For a quick trip, I usually just toss perishable food into a cooler and dump in the ice from my (house) freezer.

[Jim]

If you turn it off whenever you return from a trip, you'll likely get 7 to 10 years of useful life so I always leave mine plugged in and on all the time. The pluses for leaving it plugged in and running continuously (it's ready to go when you are!) far outweigh the minimal power usage. Your batteries are always ready too.

As far as which method cools fastest? Never saw a much of a difference those few times I had to shut it off. But my gut feeling is for my Dometic, gas was faster. Slightly. My Norcold? Seems faster with electric. I'd tend to agree that there's not enough difference to be concerned.

[gbopp]

Good question.
I don't know. I have never cooled the refrigerator on propane. I use electricity to cool it down before a trip.
I'm guessing there is not enough difference in cooling time to be concerned.

[dougrainer]

The BTU output of 120 and LP are almost identical. There are factors that affect how well and fast either source cools better. BUT, BOTH will be equal as long as all operational parameters are to spec.
1. 120 line voltage will affect 120 operation. Anything below 114 volts will not allow best 120 cooling.
2. LP gas pressure and the condition of the burner and burner Chimney will affect best LP cooling. Low(below 11 inches W/C) it will not cool as well. Dirty burner or Chimney will not allow the Heat BTU's to be efficient.
Last, for some reason some think because it is a HOT flame, it MUST cool better. NOT SO. The Flame itself cannot heat the boiler system to operational temps. So, ALL RV refers have a metal spiral baffle in the Chimney just above the flame. THAT spiral baffle causes the LP flame to disperse into a round heat source to heat the Boiler system efficiently. The 120 element is attached to that boiler system and is 6 to 8 inches long and transfers its heat directly to the boiler system. Remove that baffle and the LP would not cool at all. So, BOTH LP and 120 are even in cooling. A reason to run on LP would be if you have verified that the CG or source of 120 is below 114 volts. This may happen in areas where high RV usage and AC running has dropped the line voltage. Doug

[bluwtr49]

My Dometic doesn't seem to care which power source is used for the initial cool down or at any time as far as I can tell. Earlier this year I used my IR gun to see which started heating the fastest but checking the temp of the burner tube over the course of an hour No significant difference as I recall. Since the electric is easier for me in the barn, that's what I go with. 24 hours and the fridge is at 32 or lower.

Mine does't have the ice maker so that might makes a small difference.

[Crazy_Ray]

Electric. NAC

[BobR]

We have always run it on electric and store frozen food in freezer to assist in cool down. The frozen foods in freezer is a suggestion in my refrigerator owner's manual.

[pianotuna]

Jump start with dry ice if speed is your concern.

[Kayteg1]

Different manufacturers use different elements, but generally propane burner is the most powerful, AC element is 2nd and 12V element is the smallest.
Don't think the difference is a major, so at home I prefer to cool it down using 120V starting night, or day before and use 12V or invented 120 on the road.
Even there is nothing wrong with running propane while on the road, it is just too easy to forget about turning everything off entering the gas station. Tunnels is other issue.
My 12V element takes 16 amp, what is nothing for 120 amp alternator.

[Steeljag]

I would think equal ! I have used both methods over the years and noticed no difference.

Turn it on in the afternoon with a frozen water bottle or two, loaded it that night, and hit the road in the morning! Now, I have the standard two door fridge.....not the larger four door model!

[Dutch_12078]

Ideally, there should be no significant difference between the cooling capacity on either source, but the reality is that individual refrigerators react a bit differently for a variety reasons. We've had various models of both major brands that performed better either way, and our previous Norcold fridge performed about the same on either source.

[mike_brez]

k9dad wrote:
I am not concerned about use of propane. Just want to cool the refrigerator as quickly as possible. Which will do it? electric or propane? Or, will they both cool at the same rate?

Not shure from a initial start up what would cool down faster. I always have our rig pluged in so it's always ready to go and in the summer at home it stores all my extra beer.

[Mr_Mark1]

I find that 'solid' ice lasts longer when we transfer food to the ice chest.

I fill a zip-lock bag with water, zip it closed and put it in the house freezer. It does not melt as fast as loose ice and then I can put it back in the freezer to refreeze for the next 'transfer of food from the house to the coach'.

I also have the small ice packs to keep in the freezer so that the freezer doesn't change temp too much during defrosting.

MM.

[donn0128]

Turn it on 48 hours before departure. Fill with food 24 hours before. Done it this way for years, works just fine.