|My mom was a terrible cook, I got used to eating potatoes with a dark brown side and green beans that were more black than green. One day she fried some eggs on the gas stove. The frying pan got overheated, burned a hole in it. The leaking butter caught fire and the stove started to burn. Luckily my dad grabbed a nearby pan with soup and threw it over the stove and that distinguished the fire. We got to visit a restaurant that day!|
|Now imagine the frying pan as your fridge boiler and tubing and the melted butter as the Ammonia and Hydrogen mix inside of that. The heat source is your burning propane. As soon as you burn a hole in the boiler or tubing there is a good chance your fridge will catch fire because of the very flammable hydrogen. It is very easy to overheat your fridge, it just takes 30 seconds. The problem of overheating arises when the fridge is off level. It will not leak the first week or month but slowly over time when the fridge gets older, and the metal boiler and tubes start to rust while overheating over and over.
I hope you have your soup ready!
Is it ok to use propane to cool my fridge while driving
The actual question should be:
Should I cool my RV fridge while traveling on the road
Updated article 7/6/2020
If you only want the reason why it is a NO:
If an absorption fridge is out of level, it can heat up the boiler tubes very fast to insane high temperatures. This will deteriorate the fridge tubing every time it is getting too hot and one day it will break and leak Ammonia and Hydrogen. While the propane is burning there is a flame that can ignite the leaking Hydrogen and start a fire. The overheating does not occur that easy while on a campsite and when level. The refrigerator is made to operate within 3 degrees off level side-to-side and 6 degrees off level front-to-back (as looking at the front of the refrigerator).
It does not make a difference if you cool it on LP or Electricity, the same heat will damage the system although a fire is less likely while using electricity.
In general there 3 kinds of fridges in an RV;
1. An absorption fridge (also called an RV fridge) that can run on Propane or 120 Volts and some on 12 volts. (NOT safe to run while traveling)
2. Residential fridges that us a compressor on electricity (Safe to run while traveling)
3. Portable Chest fridge/freezers operating on 120 volts and/or 12 volts (Safe to run while traveling)
This article is about an RV absorption fridge that can run on propane and/or electricity (120 volts or 12 volts) and uses liquid ammonia as a cooling aid.
When you look at the backside of an absorption fridge it looks similar to this;
This question comes up a lot on forums and on Facebook groups and is fuel for a lot of heated discussions:
“Is it ok to drive with propane on to cool the fridge?”
The answer is NO
You will get answers like “I’m doing it for years and nothing ever happened” or “No problem, just do it” or “I never do” I’m with the last comment! During travel, we never open the fridge and it is always cold when we arrive. A big help is the fans in the fridge that circulates the cold air. Yes, it might drop a few degrees but will be still in the safe range. You are able to drive 6 to 8 hours without cooling the fridge. But never open it during that time.
Now let me say it is your RV and you can do whatever you want. My take on it switch it OFF!, Why?
While there is obviously a slew of safety features for your propane gas tanks and gas lines as stated in this article from trailer-life, these safety measures are only about your propane and not about your fridge! And guess what? The fridge is the problem, not the propane!
What people are forgetting is that if an absorption fridge is out of level it can heat up the boiler very fast to insane high temperatures, close to 800 degrees Fahrenheit. This will deteriorate the fridge boiler and tubing every time it is getting too hot and one day it will break, leak ammonia and Hydrogen, and can start a fire. The overheating does not occur while on a campsite when level. The refrigerator is made to operate within 3 degrees off level side-to-side and 6 degrees off level front-to-back (as looking at the front of the refrigerator). Operating it at more than these limits can cause damage to the cooling system and create a risk of personal injury or property damage due to a fire.
Make sure that the vehicle is level before you switch on the refrigerator*. While driving down the road that level might be compromised fairly quickly.
Gravity is critical to the RV refrigeration process. Without it, the ammonia liquid will not properly flow to the evaporator coils to cool the refrigerator. Norcold recommends that their refrigerators operate within 3 degrees off level side-to-side and 6 degrees off level front-to-back.
Compare it to a frying pan that you overheat on a regular basis, one day it will burn a hole in it. While you can see the damage of a frying pan you will not see the damage of a fridge until it is too late.
So people who told me it is safe to drive with the LPG tanks connected are somewhat right, but IT IS NOT SAFE FOR THE REFRIGERATOR (you still need to shut it off while getting fuel and in tunnels.)
The root-cause of RV fridge failure that leads to fires is the overheating of the boiler and or tubing.
Can I cool it on electricity than when I run the generator?
The answer is NO
It does not matter if the fridge runs on Propane, 120 volts or 12 volts !!!, it still heats the boiler and the tubing!
All the recalls Norcold and Dometic did will not solve this problem sufficiently while driving! Why do you think there was a class-action lawsuit that made Norcold payout 36 million dollars? The recall devices are there to cover legal responsibilities!
WHAT TO LOOK FOR?
Check your fridge on a regular basis on the back, when you smell and/or see yellow powder DO NOT USE THE FRIDGE because it leaked ammonia and hydrogen (The hydrogen is colorless) this can cause a fire when switched on, visit a dealer or call a mobile RV tech.
What a fridge fire looks like; (Facebook post 6/11/2020)
Early this morning I woke up to the smoke detector. At first I thought it was someone in the park burning trash, as we slept with the windows open, but as soon as it clicked I knew it was something worse — WE were on fire.
Within seconds we had the kids out and everyone was safe. I was able to grab my “emergency items” which we always keep handy (birth certificates, insurance papers, etc) but everything else is pretty much gone.
The fire appears to have started from the fridge (according to the bomb squad guy).
WE ARE ALL DOING FINE!!! Please don’t see this as too horrible. We have our lives, no one got a scratch, and our “stuff” is just “stuff.”
Unfortunately, insurance has a maximum of $500 per personal item — meaning that my two main computers just aren’t going to be replaced. That’s the only real bummer about the whole thing. Everything else we can just replace as needed.
As far as the coach goes — I’m hopeful our insurance company (Progressive) will treat us well. We’ve had two minor claims in the past, and they’ve shown us outstanding customer service, so I’m confident they’ll take care of us here as well.
It’s a loss — but only the loss of “stuff”.
We’re all in good spirits, even the kids, considering.
Why do DOMETIC and NORCOLD fridges fail?
The recalls of the Norcold and the domestic fridges do not really solve all problems and that’s where Fridge-Defend comes in, the all-around solution to prevent fridge fires!
The website from Fridge-defend is kind of chaotic at first, every link opens in a new tab but wading through their information is key to understand what it does.
Here is a partial list of reasons that your RV fridge can overheat, neither Dometic nor Norcold controls added after a recall address any of these issues:
- Parking Off-Level
- Driving Up/Down Steep Grades
- Failure of Electric or LP Gas Heater
- Cooling Unit Fluids Blockage or Internal Failure
- Wind Preventing Air Circulation in Cooling Unit Compartment
- Freezing Ambient Temperatures.
- Ambient Temperatures Over 100 Degrees F.
These problems and the Fridge-defend solutions are discussed on their website.
The installation is as easy as 1-2-3:
1) Decide where you want to locate the Fridge-Defend control housing.
2) Wire the power and ground from the RV to the Fridge Defend.
3) Install the temperature sensor.
It must be emphasized that this is an install overview, please reference the links to further ARP documents needed for an install and the operation of the ARP Control.
Another solution you can use is this gadget from THIA by Proteng
A cost-effective, environmentally friendly, automatic fire suppression device, that extinguishes fire from its inception. It’s a small, simple plastic tube containing extinguishing agent FM-200®. Devices come in various sizes to protect enclosed areas big and small.
They have new cooling units the same as your current fridge or replacements with helium instead of ammonia
In case you are curious how an absorption RV refrigerator works here is a great video although fairly technical!
Dometic absorption refrigerator.
1. Hydrogen enters the pipe with liquid ammonia
2. Ammonia and hydrogen enter the inner compartment. Volume increase causes a decrease in the partial pressure of the liquid ammonia. The ammonia evaporates, taking heat from the liquid ammonia (ΔHVap) lowering its temperature. Heat flows from the hotter interior of the refrigerator to the colder liquid, promoting further evaporation.
3. Ammonia and hydrogen return from the inner compartment, ammonia returns to the absorber and dissolves in water. Hydrogen is free to rise.
4. Ammonia gas condensation (passive cooling).
5. Hot ammonia gas.
6. Heat insulation and distillation of ammonia gas from water.
7. Electric heat source.
8. Absorber vessel (water and ammonia solution).
Recall fix – Norcold limiter switch reset (When the red light is on)