Fridge question

[tinstartrvlr]

Hello all,

 

I learned recently about a quirk the typical rv fridge has, and after a search on the internet and the forums, there seems to be something to it. The quirk being that the fridge doesn't cool very well when the outside temp is near or below freezing.

 

I see where some members have covered their outside vents for the fridge to help the heating element when it's cold out, but I didn't see specifics beyond just covering the lower vent.

 

For anyone who has done this, what did you use? How much did you cover? Etc.....

 

Any input is appreciated.

[Dutch_12078]

Before our Norcold fridge started failing, I kept a piece of 6 mil plastic sheeting on hand cut to fit behind the lower fridge vent for use in colder weather. I also found that at temps close to 0 deg F, running the fridge on gas seemed to maintain more consistent temps, perhaps because of the waste heat generated by the burner. Since switching to a residential fridge, I've just left the lower vent blocked all the time.

[Kirk W]

What you want is enough air for some movement but you need to keep the internal temperature warm enough that the heat source and cause the refrigerant to boil as it has to do that in order for it to change into a gas and move through the cooling coils. What I used to do was to cover all but a few of the vent openings at the bottom of the refrigerator access panel and if really cold I would run the cord for a drop light out through the open ones to plug it into the 120V power and keep that light bulb burning inside of the rear of the refrigerator to keep things warm.

 

To understand the way that an RV refrigerator works and why it needs to not freeze up inside the back, read the series of articles written by Paul Umark in the last three issues of the Escapee magazine.

[tinstartrvlr]

Thanks folks. Will check the magazine too. With any luck it won't be an issue again till later this year!

[tlerchba@sbcglobal.net]

Something else to consider, you may want to do a little research on the impact cold weather has on propane assuming you are using propane to cool your fridge.

 

Regards

Tim

[Kirk W]

Something else to consider, you may want to do a little research on the impact cold weather has on propane assuming you are using propane to cool your fridge.

I'm not sure what you refer to? I've used propane to heat with in the RV and in our WY years our home furnace burned propane?

[KodiakJack]

At very cold temperature propane will not exit the bottle. I have watched folks melting ice with a weed burner (torch connected directly to a portable propane tank) have to occasionally heat the tank with the weed burner in order to keep the gas flowing. Granted -40 is not normal RV'ing weather but keep in mind that as the temperature drops so too will the vapor pressure and hence flow.

 

Later,

J

[Kirk W]

Propane will boil, or change from liquid to gas at -43.6° F and I doubt that many RVs would be comfortable to live in anywhere close to that temperature. We experienced one night of -32°F(a record for that date in Cheyenne) in our WY winters and our furnace did just fine using propane from the tank outside with no added heat source. We lived through many nights with temperatures at or below -20°F. It is true that you need to keep a bit more in the tanks when very cold in order to keep the rated of gas production high enough.

[Max Death]

Have just spent 3 winters in Wyoming where it was not unusual to see -20 or lower. Propane worked fine in a he rv. Lived in houses with propane heat before that they all worked fine. Fortunately do not plan to be there in winter again.

The reason people heat a small bottle with a weed burner is that you are using gas at a very large rate. The outside of the bottle becomes colder than the outside temperature due to the boiling of the liquid propane. As the surface temperature of the bottle drops the propane does not boil as quickly. Adding a little bit of heat will add to the gas pressure.

Be aware that most weed burners do not use a regulator whereas an rv uses one set at 11 inches of water column. This means that the weed burner can be using as much as 10 times as much pressure as an rv. Also heating a tank with a weed burner can create over pressure problems and also can create stress cracks from unbalanced heating.

I have done this exact trick of heating a propane tank with a weed burner many times in my years but I do not recommend it.

 

Just my opinion yours may vary

[Dutch_12078]

And to put 11 inches of water column in more common form, that's about 0.4 psi.