Refrigerator solution while on the road

[Darral T.]

I've never traveled with my propane tank on...never will! (Unless it's an absolute oversight/mistake on my part). That's one danger I can avoid. I disklike propane so much, I went all electric. Now I only use my propane tank to burn my "Lil Red Campfire". EDIT: I do boondock once a year at a model airplane flyin where I burn propane in the daytime (wh & fridge) and a gen at night!

Originally Posted by Bruce H

Ok, so how many of you close the valves on your propane tanks when travelling?

[Darral T.]

I've ran my Dometic fridge (1.9) on 12v with EVERY travel since I bought my 13' Scamp in 2010. I pull with a 4 cyl Nissan Frontier. NO problems with a dead battery at anytime.

(Why does this thread seem like dejavu?)

Originally Posted by Mr Lynn

I thought it was pretty cool (as it were) to have a three-way 'fridge, but now I'm beginning to wonder what the point of having 12V capability is.

So when do you use the 12V?

/Mr Lynn

[Glenn Baglo]

Because new people join all the time.
Ever wonder how they get all those full propane tanks to the exchange centres? Or how they fill that huge propane tank at the filling station?
Ever wonder where that electricity comes from?

[Carol H]

Originally Posted by Darral T.

I've ran my Dometic fridge (1.9) on 12v with EVERY travel since I bought my 13' Scamp in 2010. I pull with a 4 cyl Nissan Frontier. NO problems with a dead battery at anytime.

(Why does this thread seem like dejavu?)

Your comment above is giving me a dejavu moment

As you well know due to your dejavu moment: that not everyone is as successful as yourself at running their fridge on 12V. Including myself who also tows with a newer Frontier with a full factory installed tow package.

The reasons for that were more than well explained on another recent thread which was actually titled "Battery Not Charging" no indication the topic was in fact the same old 12v fridge issue.

I have owned more than one 3 way fridge in the past that I was never very successful at running on 12V no matter what I was pulling the trailer with. Always landed at the campsite with a battery less than full which is not a good way to start out 4 days of dry camping.

Now I have had a 2 way that automatically switches its self over to propane - no need for me to go out and light anything I see no reason to bother with owning a 3 way.

As others have suggested if its a newer fridge and propane system, it is far safer to run while towing than it is to carry around a gas generator & the fuel cans needed to feed it, not to mention running it beside your trailer.

[Mr Lynn]

Originally Posted by Raz

I don't run my fridge on propane while travelling. It's not the propane that concerns me but the hydrogen used as part of the refrigerant. If the cooling system is going to fail, it is more likely to do so while bouncing down the road. The possibility of the cooling system rupturing, high pressure hydrogen gas being released and an open flame to ignite it is not a risk I'm interested in taking. Raz

You mean ammonia (NH3)? Hydrogen is not a refrigerant. Ammonia is not explosive.

I'd be more worried about the flame blowing out and raw propane (C3H8) filling the trailer. That is explosive.

/Mr Lynn

[Darral T.]

Welllll....if we could capture HALF of it created right here in the FGRV forums and put it in discharging bottles, we could start our own business and do away with propane completely!

Originally Posted by Glenn Baglo

Ever wonder where that electricity comes from?

[Darwin Maring]

Or gas fumes from filling up at a gas station reaching the flame.

[EllPea in CA]

Originally Posted by Bruce H

Ok, so how many of you close the valves on your propane tanks when travelling?

Ours stay closed until we're ready to use the propane.

[Borrego Dave]

Wow, this "to travel with LP on or not" comes up way to much. Millions and millions of RVs are on the road every day with lit LP refers with no problems. Of the few I've seen on the news over the years, all but one fire was by an electrical short. Never heard of even one in a crash catching fire from LP either. You've got a better chance of being hit by lighting than a LP problem. Guess everyone has to have some perceived catastrophe to worry about though and they will never see it any other way. Kind of like the recent post here of bombs in a neighboring RV......don't go to CGs anymore . OK, off the soap box but the stats just don't back up the LP concerns that some folks have. YMMV

[Glenn Baglo]

I'm switching to an organic, gluten-free, artisanal, non-flammable propane.

[Raz]

Originally Posted by Mr Lynn

You mean ammonia (NH3)? Hydrogen is not a refrigerant. Ammonia is not explosive.

I'd be more worried about the flame blowing out and raw propane (C3H8) filling the trailer. That is explosive.

/Mr Lynn

From Wikipedia:

The classic gas absorption refrigerator sends liquid ammonia into a hydrogen gas. The liquid ammonia evaporates in the presence of hydrogen gas, providing the cooling. The now-gaseous ammonia is sent into a container holding water, which absorbs the ammonia. The water-ammonia solution is then directed past a heater, which boils ammonia gas out of the water-ammonia solution. The ammonia gas is then condensed into a liquid. The liquid ammonia is then sent back through the hydrogen gas, completing the cycle.


And then there's the law suits.....

Hagens Berman: RV Owners Sue Dometic for Dangerous Refrigerator Defect Linked to Explosions and Fires | Business Wire

[C&G in FL]

Originally Posted by Raz

From Wikipedia:

The classic gas absorption refrigerator sends liquid ammonia into a hydrogen gas. The liquid ammonia evaporates in the presence of hydrogen gas, providing the cooling. The now-gaseous ammonia is sent into a container holding water, which absorbs the ammonia. The water-ammonia solution is then directed past a heater, which boils ammonia gas out of the water-ammonia solution. The ammonia gas is then condensed into a liquid. The liquid ammonia is then sent back through the hydrogen gas, completing the cycle.


And then there's the law suits.....

Hagens Berman: RV Owners Sue Dometic for Dangerous Refrigerator Defect Linked to Explosions and Fires | Business Wire

I wonder if that class action lawsuit has any similarities (in motive and/or merit) to the Johnson & Johnson talcum powder lawsuit.



Sent from my iPhone using Fiberglass RV

[Mr Lynn]

Originally Posted by Darral T.

I've ran my Dometic fridge (1.9) on 12v with EVERY travel since I bought my 13' Scamp in 2010. I pull with a 4 cyl Nissan Frontier. NO problems with a dead battery at anytime.

(Why does this thread seem like dejavu?)

Our fridge is 4 cubic feet. The ability of the TV to run the fridge no doubt depends on the amount of current the fridge draws versus the capability of the alternator in your TV, plus other factors (described in the '12V' thread recently). Does the converter in the trailer factor in, by allocating TV output to fridge and battery?

/Mr Lynn

[Mr Lynn]

Originally Posted by Raz

From Wikipedia:

The classic gas absorption refrigerator sends liquid ammonia into a hydrogen gas. The liquid ammonia evaporates in the presence of hydrogen gas, providing the cooling. The now-gaseous ammonia is sent into a container holding water, which absorbs the ammonia. The water-ammonia solution is then directed past a heater, which boils ammonia gas out of the water-ammonia solution. The ammonia gas is then condensed into a liquid. The liquid ammonia is then sent back through the hydrogen gas, completing the cycle.


And then there's the law suits.....

Hagens Berman: RV Owners Sue Dometic for Dangerous Refrigerator Defect Linked to Explosions and Fires | Business Wire

I stand corrected. Thanks for the Wikipedia link.

How many of the 'explosions and fires' in the class-action lawsuit, if any, started while traveling, as opposed to simply running the fridge while parked? Makes me wish we had a compressor-type fridge. But that wouldn't run on propane, and I must say, our Dometic refrigerator seems to work very well, while using only a little propane. . .

But I think Raz is right: turn it off while traveling, and err on the side of caution.

/Mr Lynn

[sokhapkin]

Originally Posted by Mr Lynn

Our fridge is 4 cubic feet.
/Mr Lynn

What is 12V power consumption of the fridge in watts or amperes? Which fridge model?

Dometic 1.9 draws about 10A on 12V power.

[redbarron55]

10 Amps is not that much on 12 volts.
I think that the problem for the users who want to run their fridge is the voltage drop from the alternator to the trailer battery.
To have low voltage drop the connections must be good and the wire gauge large.
there is a dedicated connection for the 12 volt for power to the trailer.
There is a separate path for the brakes so that is not a concern.
In my setup I have a 30 amp breaker that feeds a 30 amp relay that cuts off the circuit with the key off.
The breaker is there to protect the wire.
The 10 gauge wire I ran to the trailer socket is about 18 ft long and the wire to the PD4045 in the trailer is about 12 ft long.
I feed the buss on the PD4045 with a second 20 amp breaker/fuse from my terminal strip.
So we have 30 ft of #10 wire which has a resistance of 0.048 ohms.
Since the voltage drop E=IR 10 amps X .048 ohms = 0.48 volts
So we are talking about 1/2 volt drop best case.
Most alternator regulators will run about 13.75 volts at the battery terminals long term average so we will be looking at 13.25 volts at the PD4045 (best case) which is the floating voltage of a fully charged battery.
If you start with a charged battery you should be able to pretty much the maintain the battery since the refrigerator should not have to draw power all of the time.
I suspect one problem may be the circulation of air past the cooling fins of the refrigerator.
The normal circulation is by convection up and past the works in the back of the fridge.
Does anyone know what the airflow across the trailer does to the "normal" convection flow? I don't.
Most larger trailers have a vent on the roof and the intake on the side and the path is straight up and out.
With the smaller fridges the vents are both on the side and my guess is that the airflow along the side of the trailer is quite confused and perhaps the addition of a small 12 volt fan to make the airflow certain might be a worthy addition to insure proper flow.
I know on my Norcold 1200 with a side vent at the top and bottom due to it being mounted in a slide out needs additional fans to cool properly especially in the 100*F temps we have in Mobile AL. (AKA LA).
So big wires, heavy connections, clean tight plugs and sockets, and add a fan for the airflow.
If the unit cools properly it will cycle on and off giving the battery a chance to charge when the voltage goes over that 13.25 volts.
Personally I have a compressor type Norcold 704DE that does not challenge the wiring at all.

I use the above monitors for the power for both AC and DC ant they let me see what is going on quite well.

[Carol H]

Originally Posted by CPW

I wonder if that class action lawsuit has any similarities (in motive and/or merit) to the Johnson & Johnson talcum powder lawsuit.

Or the 700 claims against McDonalds for serving hot coffee

[Mr Lynn]

Originally Posted by sokhapkin

What is 12V power consumption of the fridge in watts or amperes? Which fridge model?

Dometic 1.9 draws about 10A on 12V power.

Dometic 4 cubic feet model RM 2454, 15A on 12V.

/Mr Lynn

[Darwin Maring]

If you travel to the Outter banks from north to south you are required to stop for an inspection to insure your tanks are off prior to going through a tunnel. I guess that says something about the safety of propane while towing.

[Carol H]

Originally Posted by Darwin Maring

If you travel to the Outter banks from north to south you are required to stop for an inspection to insure your tanks are off prior to going through a tunnel. I guess that says something about the safety of propane while towing.

Turning off all propane sources in confined spaces such as tunnels and ferries is the rule in most places.

For the same reason its a bad idea to run a generator in your house