To Run The Fridge On the Road Or Not??

Firstly, these propane appliances are designed to be used while in transit, as evidenced by the windscreens and design. In talking with the Fire Marshals of several states, and reviewing the intended purpose and use, it appears that they all agree that it is not a significant risk to run them while on the road. They are designed for it.

From the reports of the industry, the majority of fires start in Motorhome engines, with 12 volt wiring making up the bulk of the rest.

I agree that the best solution is to make sure you order the three way option so the fridge can run on 12 volt while in transit, which is the safest of all options, short of not traveling with any propane at all, not even in the tanks. Anecdotal evidence ("I heard") to the contrary, I have yet to see a single "source" document that indicates an RV "flame" caused the fire. I am not saying it never happened either, only that it appears to be passed around as a fact, when in fact it may be indeed urban legend. I would also like to see some links or sources. I don't state that as a challenge, simply that in calling insurance companies and talking to the Oregon DOT supervisor, and the State fire chief, they have not a single case of an RV burning down a station, nor any accidents where the propane was a causative factor. Propane will contribute to a fire, but for those who think they are safe in the event of a fire or accident with the valves closed, bear in mind that as soon as the tank or tanks are heated externally, the pressure begins to build up in the tank. As soon as it reaches 312 PSI the pressure relief valve will vent the propane in a rush. Whether that propane tank reaches that pressure from being the point of impact in a collision, or from heating, (in a fire it most certainly will reach 312 PSI!) and with the valves tightly closed, they will vent their contents. So traveling with propane, on or off, is a hazard in a fire or collision that seems to be moot either way valves on or off. The recommended standoff distance, because of the expected secondary explosions/contributions from the propane tanks, generator tanks, vehicle tanks, and other flammables, is 1500 feet if the fire cannot be contained in the first few minutes.

The propane burning appliances are vented and draw the air for their combustion from outside air. They do not draw air for their combustion from the inside of the RV. If there is no oxygen, there is no combustion. Regardless of the metal shields and thinking that the flame is contained, it is an "open flame" in that the gasoline vapors can ignite, if they are in a high enough concentration in the air the reefer or other propane appliance draws in from the surrounding air. Gasoline vapors will ignite in concentrations between 1.4% and 7.6%, and above (minus)-45 degrees, it's thermal flash point. However! Since gasoline vapors are much heavier than air, they tend to pool in low spots, and run along the ground. This might explain why there is little or no "source" documentation of RV reefers or hot water heaters, which are about three feet plus off the ground, being the primary ignition factor, in any fueling fire.

Having said that, it is imperative to stop before approaching any gasoline fueling point, and not only turn off all open flames and spark producing items, which include the hot water heater, reefer, generators, engines, BUT ALSO-to run your engine for awhile if you have just descended a hill, and the tranny, brakes, exhaust brakes, and catalytic converters are hot. A dragging brake shoe or disc can also be hot enough to ignite gasoline vapors. And are much closer to where the vapors are present. Aside from the above, it is against the law in every state to have an open flame, or running engine, when fueling with, or near gasoline pumps.

"Diesel only" areas are a different matter from a flammability perspective, as diesel doesn't even form vapors below 100 degrees F. Thus it is not listed in the national safety code as a flammable liquid, but instead a combustible liquid. But diesel will ignite on a hot surface, so if the fill nozzle is right over a hot brake, and a spill occurred, ignition could occur, as well as from a high pressure leak in the engine compartment on a hot manifold.

This discussion has generated a lot of honest debate, with some "preferences" being stated as "fact," with catastrophic and dire scenarios furnished as "proof" of one position, or ignoring the law or physical properties/design for another. Some of the assertions have been in direct contradiction of the basic physics of combustion and RV design on both sides of the discussion.

Funny that Oregon came into the discussion as I answered this question several months ago, when an Oregonian unequivocally stated that it is against the law in Oregon to travel with the propane on, in Oregon. I called the Oregon DOT and confirmed that when fueling, all open flames and sources like the engine, must be turned off. However, they stated that there have been no incidents where running with the propane on, have contributed to igniting an RV fire. They also confirmed that they see no problem with running on Oregon roads with propane appliances running, as long as they are turned off before refueling with any type of fuel. This was confirmed by the state fire marshal.

In Oregon, there is no rule against having your propane on while traveling in their state. This is directly from Oregon NFPA Code and was confirmed with the Oregon DOT today, and through the Oregon Fire Marshall's office.

The source for the information is the Oregon DOT and you can call them toll free at 1-888-ASK-ODOT to confirm for yourselves.

Here is a reprint from the email I received from the Oregon DOT supervisor:

"All ignition sources must be extinguished while fueling the vehicle, however
there is no prohibition against having a lit reefer while in transit."

Which is what we have been proposing here the whole time. The facts. Whatever your choice, extinguish all open sources of ignition before fueling, especially at islands with gasoline.

The above is a synopsis of information from authoritative sources, which are listed below.

My summaries of the data are these:

1. Running with the propane valves on could increase the risk of the propane igniting during a travel accident, but that risk is slight, and in the "catastrophic" scenarios listed, almost equal for valves off as valves on. If a rollover or severe collision occurred, not only could the gas lines rupture, but the tank and the lines at the tank could also, not to mention the heat from a fire. Conclusion: Running with the propane on is OK, from the experts. Risk increase slight, and doing it or not is a personal choice.

2. That the reefer and other appliances are indeed open flames and could ignite the gasoline vapors. And, since it is against the law to have any open flame, they must be turned off before refueling. The law does not state that there are exceptions for people that disagree, or know that gasoline vapors are heavier than air. As in all cases, some will disregard, and maybe even get caught, perhaps even be the one case we finally hear about. That decision is the same as drinking and driving. If caught, not much room to complain. Turn em off when refueling.

3. That most people are unaware of the real hazards for ignition of gasoline vapors, which are more than likely to have been responsible for any ignitions they have heard about or seen. These include hot brakes, catalytic converters, hot trannys and exhaust systems, that have not even been mentioned here, except briefly and accurately.

4. Since the original question was about a way to run the reefer from another source for safety, and since most folks will not discard a perfectly good reefer and spend $1500.00 or more for a three-way reefer, can it be done? Well, not from the inverter, but for all those that want the ultimate in safety, and not worry about shutting down the propane, in researching this answer I did find one possible solution. It is a switch that shuts down all propane when you switch off the ignition, and can be activated manually as well. Might be good or junk, I don't know, as I haven't tried one, nor can call them today, but just as a possible good compromise, worth looking into if only for an interesting compromise device for under 100 bucks.

If my conclusions are not what you wanted to hear, please read the below sources, and perhaps some of them will become clearer. For those that want to have no safety risks, driving multiple tons of rig down the road is also a bigger risk than not. However, for those interested in real fire and refueling safety, the below may add a few items to your refueling and travel checklists.

Article on other fire safety hazards you might not have considered
http://www.rvaa.com/articles/safe_fuel_pump.php3

Recommendation for turning off all propane appliances before fueling, did you know you need to fully open the propane valves for the excess flow valve of your tank/s to be operable?
http://www.rvaa.com/articles/propane2.php3

More fire safety for RVs and diesel Vs gasoline vapor points
http://www.wbcci.org/html/body_maintenance_tips.html

Maybe a 94 dollar solution?
http://www.lslproducts.com/FOPage.html

Gasoline vapor flash point and concentrations
http://www.chemistry.ohio-state.edu/ehs/handbook/flammabl/firetech.htm

Gasoline heavier than air and pools in low spots as well as running along the ground to ignition sources. Diesel fuel needs above 100 degrees to even produce vapor.
http://www.eig.com/ssus/ssu9706.html