Running a Fridge on Gas on the Move?

[aandncaravan]

pepe63 - 2017-11-17 2:49 PM

 

aandncaravan - 2017-11-17 12:26 PM

 

Pepe63, I find your reply quite offensive. Make a sound counter argument, but no need to be nasty.

 

..and I find someone "suggesting" on a public forum that it's okay for folk to drive around in vehicle with it's fridge lit on gas, both ridiculous and dangerous ( especially coming as it does from someone who supposedly has a large degree of practical and technical nous...?)

 

"Sound counter argument"?...errr?..It's a daft idea to drive a vehicle with a naked gas flame, sitting just behind crude plastic grill? (as I, and others, have posted).

 

)

 

I am not suggesting any one does anything, I am pointing out the obvious options, if you are one of those who gets worried when Halloween comes around then it's probably a risk you don't want to take.

But saying "it's a daft idea" is not a logical counter argument.

It is the reply of someone who doesn't actually know why they are chipping.in.

 

I used to be in a Classic Car club where someone had a Stanley Steamer, that has just a little bit more than a tiny naked flame.

No one slapped him with a 'Dangerous unfit to be on the road order". In the 60's Sentinel Steam Lorries were also not unusual where I lived.

 

Before you get too uptight about naked flames on Petrol Forecourts, just think how many cars drive on there with red hot DPF/Cats/Exhaust headers//Turbos EVERY day?

Quite a few without issues?

 

Cars with sparking Ignition leads were common until decent Silicone Ignition Leads arrived in the eighties. In case you don't know it is the 'Spark' that ignites the fuel on a Petrol engine.

 

I had a Motorbike where I could actually see the Sparks in the Dark from around the Distributor Cap. Never ignited or blew up any forecourts.

 

What is the difference between a Harley backfiring flames and a Fridge Flame in a shrouded shield? I will tell you a HUGE amount of heat.

 

So 'Petrol Vapour igniting 'vehicles go through our forecourts EVERY day.

 

You might be surprised to know that Petrol Forecourts have pretty high standards to meet on Vapour/Fuel release and have to react accordingly.

 

Did you know that a modern 'Filler' incorporates a suction device to reduce vapour release during refuelling?

 

So a Naked flame, although clearly not a good idea, is not the automatic disaster you seem to assume.

 

 

I AM NOT SUGGESTING ANYONE TESTS A FORECOURTS SAFETY, just pointing out that there are many things going on each day without adverse effect.

Many steps have already been taken to reduce risks to an absolute minimum, and not for a Motorhomes Fridge.

 

Of course safety should be a priority and why I say in my very first post, I avoid forecourts when the Fridge is on Gas.

 

On the 30th September Daryl White emailed from France -

"Hi Had a bit of a problem on return from holiday as smoke was coming up through my wifes legs from under her seat. This Fridge connector on the attached photo is what the problem was. Is there a chance you can help. I would also need a new 5 pin plug as that is burnt as well Many Thanks Regards Darryl.

 

Original email available for scrutiny if required

 

In my opinion, that is a greater fire risk and until I see with my own eyes a burning motorhome with a ruptured gas pipe near the Fridge, it will be given a higher risk factor.

 

 

 

[colin]

aandncaravan - 2017-11-17 6:42 PM

 

Before you get too uptight about naked flames on Petrol Forecourts, just think how many cars drive on there with red hot DPF/Cats/Exhaust headers//Turbos EVERY day?

Quite a few without issues?

 

 

Epic fail.

You can pour a gallon of petrol over a hot turbo and odds are it won't catch light, but add a source of ignition such as a naked flame and that petrol will go up in a ball of flame.

[aandncaravan]

colin - 2017-11-17 6:53 PM

 

 

Colin you write - "Epic fail.

You can pour a gallon of petrol over a hot turbo and odds are it won't catch light, but add a source of ignition such as a naked flame and it will go up in a ball of flame".

 

Or a source of ignition like a spark?

 

Funny how you are taking the opposite stance to Will who says it is all about the vapour that ignites and he says it is the vapour that is the risk?

 

Sorry but I do not believe petrol vapour coming into contact with a red hot turbo will not ignite if the ratio is right.

If it is too weak, as almost all forecourts should be, it will be benign.

 

And that is the key, Petrol Forecourts take steps to ensure the vapour is to weak to ignite. You can smell it, but unless it is the right ratio with air, it won't ignite.

 

Vented Battery gas is a bigger risk in my opinion as that ignites exceptionally easily at very low 4% Hydrogen/Oxygen ratios. Very often the vents are near the front of the van and exhaust.

 

 

 

[Brian Kirby]

Safety aside, I can think of two reasons why this is not a good idea.

 

1 Despite Allan's assertion that the fridges are designed to operate in high winds, my own experience is that the gas flame can be blown out even when static. Taking account of the slip stream from trucks and coaches, which are easily sufficient to give the whole van a good "shove" while passing/being passed, I think the chances of reaching journey's end with the fridge still working fairly remote.

 

2 There is a huge difference between the Truma flueing arrangement and that of all the fridges I have encountered (no expert, the total is 5! :-)). The Truma heaters that can be gas fired while travelling have a balanced flue arrangement, with a fan to supply combustion air and extract exhaust gases. This ensures that air pressure fluctuations cannot cause sudden air movements within the sealed combustion chamber.

 

Truma's instructions for a current model Combi 4/6 state:

 

"Operation while driving

 

– Directive UN ECE R 122 stipulates that a safety shut-off device is required if motor homes and caravans are heated while driving. The Truma MonoControl CS gas pressure regulation system satisfies this requirement. Throughout Europe, a type-tested liquefied gas heating system may be used while driving (according to the directive UN ECE R 122) if the system includes a gas pressure regulator with an appropriately configured gas installation. National regulations and rules must be followed.

– If no safety shut-off device (e.g. as contained within the Truma MonoControl CS gas pressure regulation system) has been installed, the gas cylinder must be closed when driving and information signs must be attached in the gas cylinder protection box and in the vicinity of the control panel.

–Liquid gas equipment must not be used when refuelling, in multi-storey car parks, in garages or on ferries."

 

Note that this regulation has wider jurisdiction that the EU alone.

 

OTOH, fridge flues are simple, non-fanned, open flues, that rely on a natural convection draught to ensure that the flue gases escape. Combustion air is drawn through a low set external grille (that also supplies air to the condenser coils at the rear of the fridge), passes by natural draught over the naked flame, and exits (usually) through the gas flue terminal incorporated into the upper fridge ventilation grille. Natural draught flues rely on very feeble differences in buoyancy between warm and cool air. That is why they not infrequently blow out (in my experience) under extreme conditions.

 

Operating instructions for a typical RM 7 series Dometic fridge state:

 

"Gas operation

- The refrigerator should only be operated using liquid gas (propane, butane). Do not use town gas or natural gas.

- If the refrigerator is operated during travel using gas, the precautions stipulated by the legislation in the respective country must be taken (in conformity with the European standard EN 732).

- Operating the refrigerator with gas is not permitted during travel in France and Australia.

- As a basic rule, operation using gas is prohibited in petrol stations."

 

So, assumed permissible (subject to national regulations). However, for the reason stated above I would not choose to do so. A bad dose of Montezuma's revenge on holiday as a result of warming food in a fridge that had "blown out" un-noticed while travelling, seems a high price to pay for saving the cost of repairing the 12V system.

 

I should add that I am inherently suspicious of risk assessments that begin from the standpoint that X is a small risk when compared to Y, so should be accepted. Risk Y (greater) does not compensate for (smaller) risk Y: the end point is risk X + risk Y, a higher risk environment.

 

The filling station risk is not imaginary, it is why the law forbids naked flames on filling stations. It is a small risk, but with potentially catastrophic, even fatal, consequences. After a few hours driving, with all its distractions, who can guarantee to remember to always turn off the fridge before pulling onto a filling station forecourt? Blowed if I could! :-)

[colin]

aandncaravan - 2017-11-17 7:01 PM

 

colin - 2017-11-17 6:53 PM

 

 

 

"Epic fail.

You can pour a gallon of petrol over a hot turbo and odds are it won't catch light, but add a source of ignition such as a naked flame and it will go up in a ball of flame".

 

Or a source of ignition like a spark?

 

Funny how you are taking the opposite stance to Will who says it is all about the vapour that ignites and he says it is the vapour that is the risk?

 

Sorry but I do not believe petrol vapour coming into contact with a red hot turbo will not ignite if the ratio is right.

If it is too weak, as almost all forecourts should be, it will be benign.

 

And that is the key, Petrol Forecourts take steps to ensure the vapour is to weak to ignite. You can smell it, but unless it is the right ratio with air it won't ignite.

 

Vented Battery gas is a bigger risk in my opinion as that ignites exceptionally easily at very low 4% Hydrogen/Oxygen ratios. Very often the vents are near the front of the van and exhaust.

 

 

 

I'm not taking the opposite stance to Will, what I'm 'saying' is it needs a source of ignition, and a naked flame is a suitable source of ignition.

[Brian Kirby]

aandncaravan - 2017-11-17 7:01 PM

 

colin - 2017-11-17 6:53 PM

 

"Epic fail.

You can pour a gallon of petrol over a hot turbo and odds are it won't catch light, but add a source of ignition such as a naked flame and it will go up in a ball of flame".

 

Or a source of ignition like a spark?

 

Funny how you are taking the opposite stance to Will who says it is all about the vapour that ignites and he says it is the vapour that is the risk?

 

Sorry but I do not believe petrol vapour coming into contact with a red hot turbo will not ignite if the ratio is right.

If it is too weak, as almost all forecourts should be, it will be benign.

 

And that is the key, Petrol Forecourts take steps to ensure the vapour is to weak to ignite. You can smell it, but unless it is the right ratio with air it won't ignite.

 

Vented Battery gas is a bigger risk in my opinion as that ignites exceptionally easily at very low 4% Hydrogen/Oxygen ratios. Very often the vents are near the front of the van and exhaust.

There is a difference Alan. It is the vapour and not the liquid fuel that ignites. Petrol is highly volatile, so vaporises readily. But, for the vapour to ignite, it requires a source of ignition (a flame, or a temperature greater than roughly 280C). Hot surfaces below that temperature only cause increased vaporisation, so the fire will be more intense when ignited.

[pepe63xnotuse]

aandncaravan - 2017-11-17 6:42 PM

 

I am not suggesting any one does anything, I am pointing out the obvious options, if you are one of those who gets worried when Halloween comes around then it's probably a risk you don't want to take

 

*ahem* ...Quote(from your first post) " We therefore suggested that one option is to bin the ability to run the Fridge on 12v and use Gas while on the move. ;-)

 

Presumably, as this enquiry came to you in a "technical/professional" capacity? (..and it wasn't just a couple of mates chatting down the pub), you ran your advice past the likes of Dometic first? (or whoever made this bloke's fridge?)...

It would be interesting to here their take on it.......

It may have also been prudent to get him to have a word with his insurance company and seek their stance on it....?

 

Actually, I quite like Hallowen...but that doesn't usually involve many "..I know better..rules and guidelines are for other people...I haven't blown up yet." types... (lol)

[Alanb]

Robbo - 2017-11-17 11:19 AM

 

Thankfully, I have a CBE system where the high electrical currents to the fridge are connected to the PCB with screw-down studs and NOT connect :-D

 

Sorry Robbo,

 

Unfortunately that is not correct. The CBE distribution boards use 6mm studs for the input from B1 (vehicle battery), B2 (leisure battery), and negative. The DS520 also has a 6mm stud for charger connection. (Four studs in total.)

 

The fridge output is via a Mate-N-Lock connector. When I investigated these connectors after purchasing my PVC about 11 years ago, I was concerned to find a rating of only 8A for commercial grade connector inserts. As on the CBE DS520 at least there are two connector poles designated for the fridge, I arranged a parallel connection in conjunction with increased conductor size to existing bullet connectors behind the fridge.

 

Perhaps the rating of the inserts has been stretched over the years, as I think that I have seen higher ratings quoted.

 

Recently for some reason that I cannot recall, I examined the bullet connectors behind the fridge and I was concerned to find that one of the connections had been getting hot. On investigation the wire was loose inside the crimp. From the crimping pattern the faulty connection was the converter's original, and not my replacement.

 

Alan

[aandncaravan]

Brian Kirby - 2017-11-17 7:19 PM

 

aandncaravan - 2017-11-17 7:01 PM

 

colin - 2017-11-17 6:53 PM

 

"Epic fail.

You can pour a gallon of petrol over a hot turbo and odds are it won't catch light, but add a source of ignition such as a naked flame and it will go up in a ball of flame".

 

Or a source of ignition like a spark?

 

Funny how you are taking the opposite stance to Will who says it is all about the vapour that ignites and he says it is the vapour that is the risk?

 

Sorry but I do not believe petrol vapour coming into contact with a red hot turbo will not ignite if the ratio is right.

If it is too weak, as almost all forecourts should be, it will be benign.

 

And that is the key, Petrol Forecourts take steps to ensure the vapour is to weak to ignite. You can smell it, but unless it is the right ratio with air it won't ignite.

 

Vented Battery gas is a bigger risk in my opinion as that ignites exceptionally easily at very low 4% Hydrogen/Oxygen ratios. Very often the vents are near the front of the van and exhaust.

There is a difference Alan. It is the vapour and not the liquid fuel that ignites. Petrol is highly volatile, so vaporises readily. But, for the vapour to ignite, it requires a source of ignition (a flame, or a temperature greater than roughly 280C). Hot surfaces below that temperature only cause increased vaporisation, so the fire will be more intense when ignited.

 

Brian, you seem to be disagreeing with but then repeat everything I wrote?

 

I understand all that, hence me writing that a Spark was a source of Ignition yet still didn't cause an issue during the 60s, 70's, etc. nor did backfiring cars with flames out the exhaust.

 

I did also point out, that vapour coming into contact with a red hot turbo would ignite because the temperature was so high?

I didn't say anything about liquid petrol, which was Colin's Red Herring, not mine?

 

 

Pepe63, Notice you are still unable to argue why it is dangerous and exactly what the risks are?

 

 

 

 

I don't think there is any more for me to add, up to those who want to consider the options and make their own decision?

 

Heartening for me that not one respondee has challenged my myth breaker that running the Fridge on 12v costs and that the Gas option while driving, is not the higher expense option many probably previously perceived.

 

 

At least there is more information on the table, right or wrong.

 

 

 

[rupert123]

Will86 - 2017-11-17 6:14 PM

 

Its totally unfair to comment that the non users of lighted gas when travelling are scared etc.

 

The fact's are that I have no intention of putting my family or other road users at risk by allowing even the slightest chance of injury to occur. I've worked with industrial gasses for 76 years and know the possibilities.

 

Risk assessment is the modern term and while there is always a risk I will abide by my own survival laws.

How can you make a statement like this with a straight face. If you are adverse to taking the slightest chance on injury I would suggest you take your van off the road straight away.

[aandncaravan]

Someone just emailed pointing out something in Brians post that I missed, which addresses many of the concerns above.

 

Brian, thank you for the information suggesting that Fridge manufacturer Dometic and the RM 7 Fridge IS designed to be used on the move and it IS legal to use in most countries -

 

"If the refrigerator is operated during travel using gas, the precautions stipulated by the legislation in the respective country must be taken (in conformity with the European standard EN 732).

- Operating the refrigerator with gas is not permitted during travel in France and Australia".

 

 

That information suggests that the manufacturer EXPECTS it to be run on Gas on the move in Germany, UK, Belgium, Holland, Spain, Portugal, Austria, Norway, Italy, etc.

 

It most definitely doesn't advise against it, nor does it suggest there are any safety issues. That suggests it will be designed to cope with that eventuality.

 

Only safety concern, just as we said and do, is avoiding Fuel Stations.

 

 

To reiterate what we say all through the post, we do not advise anyone does this, but it is an option open to most.

 

 

[paul2]

Hi

I have left my fridge running on gas and drove with out thinking, remember about 3 miles up the road and stopped to turn it off and it had gone out!

Paul

[aandy]

"Heartening for me that not one respondee has challenged my myth breaker that running the Fridge on 12v costs and that the Gas option while driving, is not the higher expense option many probably previously perceived."

 

I'm not challenging it, since the basic rules of physics tell us you can't get something for nothing. I had, however, always assumed that the additional fuel burn resulting from any extra load on an alternator would be so small as to be immeasurable. Do you know of any tests that have been done to establish precisely how much extra fuel would be used?

[StuartO]

aandy - 2017-11-19 12:02 AM"Heartening for me that not one respondee has challenged my myth breaker that running the Fridge on 12v costs and that the Gas option while driving, is not the higher expense option many probably previously perceived."I'm not challenging it, since the basic rules of physics tell us you can't get something for nothing. I had, however, always assumed that the additional fuel burn resulting from any extra load on an alternator would be so small as to be immeasurable. Do you know of any tests that have been done to establish precisely how much extra fuel would be used?

 

DIY testing isn't going to be practicable but it should be possible to calculate the cost of running the fridge on 12v in fuel if you can be bothered.  The wattage of the 12v heating element will determine the power it consumes, which will determine the power it draws from the alternator (about 10 amps?) which determines the power necessary to drive the alternator for that purpose which determines the additional fuel used by the engine.  Electricity generated by a diesel engine is usually a lot more expensive than any other generation, so maybe that give a clue.

 

I've noticed that the heat coming from the top fridge vent is greater when the fridge is on gas than when its on 12v electrics (or mains) so maybe that indicates that running the fridge on gas is more energy consuming but I assume that this is merely a reflection of the heat output of the minimum-sized gas burner setting for a stable flame and I'm not sure that running a fridge on 12v for long periods would actually keep it cool enough.  But then LPG is only about half the price (per litre, and probably per unit of energy) than diesel.

 

Taking all this into account, I would guess that running your fridge on lpg isn't likely to be significantly more expensive than using 12v generated by the engine when you are moving - but then you need to make your risk assessment of whether (and where) it will be safe to do so!

 

[aandy]

Thanks Stuart. I wasn't thinking specifically about fridges, but about the whole question of whether additional load on a vehicle's electrical system would noticeably affect fuel consumption. While a theoretical calculation is obviously possible, I wonder whether it would actually be detectable in practice or be absorbed into the various frictional losses already present. Not a scientific test I know, but I once set the idle speed on my car to the lowest at which it would run smoothly then turned on lights, fan, and heated rear window to see whether there was any noticeable increase in load on the engine - there wasn't. As I said, not adding to the fridge debate, just curious.

 

The only thing I can say in relation to the original discussion (sorry for the thread drift) is that before I had an AES fridge I did occasionally forget to change from gas to 12v before leaving a site and the fridge always stayed alight, sometimes after several hundred miles.

[StuartO]

aandy - 2017-11-19 1:14 AM.... I did occasionally forget to change from gas to 12v before leaving a site and the fridge always stayed alight, sometimes after several hundred miles.

 

I wonder if the reason why the gas exhaust is hotter is because they set a more substantial flame size than is necessary purely for cooling the fridge in order to reduce the risk of the flame blowing out?

 

[lennyhb]

It is against the Road Traffic Act (I think its the 1986 act) to run any gas appliance with a naked flame in a vehicle. The fridge has a naked flame so the answer is NO you can't run it on the move.

I also find it quite alarming that someone of Alan's experience has suggested this also no mention of the safety requirements for using gas on the move such as crash protection regulators & ant-rupture hoses.

[chas]

My 12v element packed in earlier in the year, but feel I can live without it. The element only tries to maintain the temperature in use, not very successfully it appears, So in my case starting off with a nice cold fridge will last to where ever I'm going.Then on to gas. I leave my gas on if moving the van on site for water filling ect,.

 

I would rather save the £100 on replacing the element and use it on fuel/site fees/meals. Get the fridge nice and cold before setting off anywhere, don't open the fridge door to often on route and it will be fine on arrival to quickly cool up again on gas. Works for me

:-D

[aandy]

lennyhb - 2017-11-18 12:29 PM

 

It is against the Road Traffic Act (I think its the 1986 act) to run any gas appliance with a naked flame in a vehicle. The fridge has a naked flame so the answer is NO you can't run it on the move.

I also find it quite alarming that someone of Alan's experience has suggested this also no mention of the safety requirements for using gas on the move such as crash protection regulators & ant-rupture hoses.

 

I've had a quick skim through the RTA (1988) and could find no such prohibition, though if there were one I would think it more likely to be in the Construction and Use Regulations. There is a great deal in those regulations (schedule 5) about how gas appliances should be installed etc but nothing that I could see prohibiting their use on the move. I believe - though I stand to be corrected - that both Truma and Eberspacher make heaters that use a flame and are designed for use on the road, so unless I'm mistaken an outright prohibition would seem unlikely.

[Robinhood]

lennyhb - 2017-11-18 12:29 PM

 

It is against the Road Traffic Act (I think its the 1986 act) to run any gas appliance with a naked flame in a vehicle...........

 

...as posted above, the use in motion is governed by The RTA Road Vehicles (Construction and Use) Regulations 1986.

 

Whether it is legal or not will depend on interpretation of a sentence at Section 96(3)© which has too many "ands/ors", and too few commas for my liking, but on balance and a re-read I would say it allows a refrigerator to be run whilst in motion (regardless of a naked flame), but nothing else (which exposes a naked flame).

 

It also appears to be dumb on the use off excess flow/crash sensors on the bottles (though a flame-failure device on the appliance is a must).

 

Whether it be legal or not, I certainly wouldn't choose to do it, and find it quite an odd suggestion in the way it was put forward (though I am aware that the North American market has seen this as a "norm").

 

TBH, if it were a perfectly logical thing to do with European fridges, I think the manufacturers would, by now, have removed 12V operation as a cost-saving measure. ;-)

[Brock]

Always thought a suggestion was something put forward for consideration. In my book a suggestion is not advice; it puts the obligation on the individual whether the suggestion is suitable for their circumstances. I've taken what Alan says with this in mind. I would have thought anyone going abroad in their van would have the sense to research and comply with the laws of the country being visited but perhaps I am naive.

 

According to Dometic, my fridge can use gas on the road; Truma says that to operate the gas system while you’re travelling, according to the European Gas Appliances Directive you need a gas pressure regulator with a safety shut-off function. Truma gas pressure regulators with crash sensor fulfil all the standards. I have the Truma system fitted so I can run my fridge on gas when driving until someone tells me otherwise [i don't though].

 

The Road Vehicles (Construction and Use) Regulations 1986

Use of gas-fired appliances when a vehicle is in motion

 

96.—(1) Subject to paragraph (2), this regulation applies to every motor vehicle and trailer.

 

(2) Paragraphs (3) and (4) do not apply to a vehicle constructed or adapted for the conveyance of goods under controlled temperatures.

 

(3) No person shall use, or cause or permit to be used, in any vehicle to which this paragraph applies, while the vehicle is in motion on a road, any gas-fired appliance except—

 

(a)a gas-fired appliance which is fitted to engineering plant while the plant is being used for the purposes of the engineering operations for which it was designed;

(b)a gas-fired appliance which is permanently attached to a bus, provided that any appliance for heating or cooling the interior of the bus for the comfort of the driver and any passengers does not expose a naked flame on the outside of the appliance; or

©in any other vehicle, a refrigerating appliance or an appliance which does not expose a naked flame on the outside of the appliance and which is permanently attached to the vehicle and designed for the purpose of heating any part of the interior of the vehicle for the comfort of the driver and any passengers.

[Derek Uzzell]

This French caravanning forum thread discusses operating a fridge on gas while travelling

 

http://www.lescaravaniers2.com/forums/viewtopic.php?t=6497

 

EN 1949-12684-13786 is cited as being relevant and the ‘French Exception’ is highlighted.

[Will86]

rupert123 - 2017-11-17 8:29 PM

How can you make a statement like this with a straight face. If you are adverse to taking the slightest chance on injury I would suggest you take your van off the road straight away.

 

I do not travel assuming I or anyone else is at some time going to be injured. I travel with the object of preventing it.

 

All those who travel with their gas alight are in my view committing an offence and have no consideration for the safety of others.

 

A similar situation happened recently when the Grenfell Tower Fire occurred. The designers said its SAFE. The authority said its SAFE. Many of the residents assumed it was SAFE .................................. then there was a fire ..... and they all said ... Oh Dear !

[StuartO]

Brock - 2017-11-19 5:29 AM.... or© in any other vehicle, a refrigerating appliance or an appliance which does not expose a naked flame on the outside of the appliance and which is permanently attached to the vehicle and designed for the purpose of heating any part of the interior of the vehicle for the comfort of the driver and any passengers.

 

As I understand that, any type of refridgerating gas appliance is OK.

 

[aandy]

But they're not. As Brock has identified, the legislation expressly permits it.