propane/electric 2 way refrigerator

[cherv]

which is faster cooling propane or electric? I have noticed by switching to propane in 90+ degree weather from electric the frig. stays cooler yet I have read that electric gives a more stable cooling. on electric frig. was at 50 degrees, on propane frig. was at44 degrees. coach was warm, no AC on parked in our driveway and frig. side of coach in shade.

[shootist]

44 is not near cool enough, turn it to 9 and see what happens on propane. Give it another day to cool. Propane should cool better.

[cherv]

our frig. has 5-***** stars. we set it to 3-*** which usually keeps frig. at 36 degrees. will set it to 4-**** and see. never had to go beyond 3-*** before.. thanks

[Unplanned Tourist]

We spent 5 days dry camping, no AC and our 4 door 1210 never went above 4 F and 38 F. It was up to 90 F and we had no shade, only the awning facing West.

Do a couple modifications like an extra fan behind controlled by a “Fridge Defend” and also a couple or 3 small fans in the fridge blowing air on the cooling fins.

We were using strictly propane as well. So with a few modifications, even with the factory cooling system, they can work well.

[sibe]

Originally Posted by Unplanned Tourist

We spent 5 days dry camping, no AC and our 4 door 1210 never went above 4 F and 38 F. It was up to 90 F and we had no shade, only the awning facing West.

Do a couple modifications like an extra fan behind controlled by a “Fridge Defend” and also a couple or 3 small fans in the fridge blowing air on the cooling fins.

We were using strictly propane as well. So with a few modifications, even with the factory cooling system, they can work well.

I have older typical rv 2 way norcold... I use propane alot and AC when I can..

Since I added a set of fans to the plenum and a thermostat to turn on .
Freezer stay frozen and the fridge works well.. naturally dont open/close door 20 times a day.. LOL

After the mods maybe Propane is faster to cool on start up but once cool it seems the same...

[Fridge Defend]

Originally Posted by cherv

which is faster cooling propane or electric? I have noticed by switching to propane in 90+ degree weather from electric the frig. stays cooler yet I have read that electric gives a more stable cooling. on electric frig. was at 50 degrees, on propane frig. was at44 degrees. coach was warm, no AC on parked in our driveway and frig. side of coach in shade.

Let's address the ambient temperature first, then let the facts drop out.


Based on the ambient temperature, one has to take into account that the propane gas puts heat into the cooling unit compartment.


Thus, you fridge should cool as well or better on shore power due to the fact that the 120VAC allows the cooling unit compartment to run much cooler because there is not the heat from the flue to reject.


I did not see which fridge make and model you have, I can better advise when I know what fridge, and what the configuration is?


Click here for the configuration I am asking about.



Thanks Unplanned Tourist for the kind comments, I would say that the boiler temperature is critical for troubleshooting in the situation. Unplanned Tourist, use your Display button to read the difference in boiler temperature between your propane gas and shore power boiler temperatures, you will see that they are going to be a little different, but not too much.


It sounds like Cherv has an issue with his electric heaters from what I hear.


Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts, Paul and Mao

[powercat_ras]

Originally Posted by cherv

which is faster cooling propane or electric? I have noticed by switching to propane in 90+ degree weather from electric the frig. stays cooler yet I have read that electric gives a more stable cooling. on electric frig. was at 50 degrees, on propane frig. was at44 degrees. coach was warm, no AC on parked in our driveway and frig. side of coach in shade.

The refrigeration cycle uses heat from either a propane flame or electric heating element to drive an absorbtion refrigeration cycle to extract heat from the freezer and refrigerator sections. The cycle is controlled by the control board based on the temp probe in the refrigerator section. Normally the cycle is being started and stopped to maintain a temperature range and not continuous.

The propane flame puts out less heat as altitude increases. Dometic and Norcold size the propane flame to operate the refrigerator at up to 8,000 feet.

At 8,000 feet the electric and propane modes would provide the same amount of maximum cooling.

As you drop in altitude the max cooling of electric stays the same but max cooling on propane increases.

Bottom line, when you need max cooling you will do better on propane unless you are at high altitude.

[cherv]

this am outside temp was 58 a far cry from 95 yesterday. frige is back to normal temp. thanks.....will look at use of multiple inside frig fans. had one running yesterday, thanks...

[ArtJoyce]

I have had it both ways on the campers I have owned. But most time electric is the winer.

You just have to test your to come up with the winer. They should come out about the same. But electric coil not running at the right watts or a dirty propane burner makes a diffrence.

[avfordguy]

Absorption fridge will work better if you keep the condensor at the proper temp, there are a lot of variables that need to be considered. Normal convection is not adequate at 90+ temps, a computer fan under the condensor fins will help the convection. Never put a fan in the lower section as it will cool the boiler and produce less interior cooling.

[Old-Biscuit]

Both Gas & Electric TRANSFER roughly the SAME amount of heat to the boiler (perk tube)
Electric is roughly 325*F via 'Conductive' heat transfer (contact...metal to metal)
Gas is roughly 350*F via 'Radiant' heat transfer (spiral baffle absorbs heat from flame and radiates it to the perk tube)

Gas is bit quicker to Start the process due to temp of propane flame/radiant heat
But once freezer starts cooling down ......both should perform roughly the same

Absorbtion fridges........need to be 'level' and can take 12 hrs to reach temps ---hotter the ambient temps & inside RV temps the longer cool down can take
Airflow/DRAFT is critical to cooling ----heat generated by ammonia being boiled then condensed has to be removed.