Carbon Monoxide

[Gaytowers]

A quick question for all you caravan buffs: we pick up our new caravan in 8 days and I've noticed that the kitchen air vents are on the same side as the awning. does this mean that if we run the fridge on gas overnight any carbon monoxide produced will collect in the awning? and how late should i let my husband sleep for it to take full effect?

[Stevan]

If the fridge is operating correctly there should not be any carbon monoxide! It only forms if the flame in not getting enough oxygen.

 

The amount of carbon dioxide should not be a problem unless you have managed to remove all ventilation from the awning.

[Brecon]

Quote " If the fridge is operating correctly there should not be any carbon monoxide! "

 

That statement is incorrect, as is this one: " It only forms if the flame in not getting enough oxygen."

 

Yes there will be some Carbon Monoxide produced by any fuel burning product. The fridge on gas will produce CO.

 

However, if the fridge is working correctly the amount should be very low, in the region of 0. 0003 percent ratio to Carbon Dioxide.

 

Regarding the vents in the awning, that has been the case for many years and as the awning is not a sealed unit and has plenty of ventilation, even with the door and windows closed, it presents no problem.

 

The problem you will get is during hot weather the awning temperature can and does rise to over 100 degrees which will cause your fridge to have problems working as it gets too hot.

 

As for the second statement ( It only forms if the flame in not getting enough oxygen.), CO is formed whenever the flame is impinged (it burns with some kind of obstruction in the way) and as the flame passes over the flame recognition probe it produces CO.

 

Similarly when using a gas hob, CO is produced when the flame comes into contact with the trivets and pan bases, as well as the flame recognition probes.

Edited May 11, 2017 by Brecon

[KNARF]

Quote:
"Propane undergoes combustion reactions in a similar fashion to other alkanes. In the presence of excess oxygen, propane burns to form water and carbondioxide.

• C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O + heat
  Propane + Oxygen → Carbon Dioxide + Water

When not enough oxygen is present for complete combustion, incomplete combustion occurs when propane burns and forms water, carbon monoxide, carbon dioxide,and carbon.

• C₃H₈ + 3. 5 O₂ → CO₂ + CO + C + 4 H₂O + heat
  Propane + Oxygen → Carbon Dioxide + Carbon Monoxide + Carbon + Water"

 

knarf

[Brecon]

 

Quote:

"Propane undergoes combustion reactions in a similar fashion to other alkanes. In the presence of excess oxygen, propane burns to form water and carbondioxide.

• C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O + heat

  Propane + Oxygen → Carbon Dioxide + Water

When not enough oxygen is present for complete combustion, incomplete combustion occurs when propane burns and forms water, carbon monoxide, carbon dioxide,and carbon.

• C₃H₈ + 3. 5 O₂ → CO₂ + CO + C + 4 H₂O + heat

  Propane + Oxygen → Carbon Dioxide + Carbon Monoxide + Carbon + Water"

knarf

And your point is?

 

It is all very well quoting results obtained in laboratory conditions but caravans are not labs and the lab results were with nothing impinging the flame and using 100% pure propane.

 

Once you introduce obstructions to the flame you get CO, its as simple as that, or have I and the hundreds of other Gas Safe Engineers been wrong for a very long time ???????????

[Stevan]

Quote " If the fridge is operating correctly there should not be any carbon monoxide! "

 

That statement is incorrect, as is this one: " It only forms if the flame in not getting enough oxygen."

 

Yes there will be some Carbon Monoxide produced by any fuel burning product. The fridge on gas will produce CO.

 

However, if the fridge is working correctly the amount should be very low, in the region of 0. 0003 percent ratio to Carbon Dioxide.

 

Regarding the vents in the awning, that has been the case for many years and as the awning is not a sealed unit and has plenty of ventilation, even with the door and windows closed, it presents no problem.

 

The problem you will get is during hot weather the awning temperature can and does rise to over 100 degrees which will cause your fridge to have problems working as it gets too hot.

 

As for the second statement ( It only forms if the flame in not getting enough oxygen.), CO is formed whenever the flame is impinged (it burns with some kind of obstruction in the way) and as the flame passes over the flame recognition probe it produces CO.

 

Similarly when using a gas hob, CO is produced when the flame comes into contact with the trivets and pan bases, as well as the flame recognition probes.

Yes, In my attempt to simplify, I omitted the words " significant amount of" after the word "any".

[KNARF]

The point is you stated:

"That statement is incorrect, as is this one: " It only forms if the flame in not getting enough oxygen."

"Yes there will be some Carbon Monoxide produced by any fuel burning product.

That is incorrect!

AS the equation shows in an ideal situation it won't produce CO

 

The reason that it produces CO is because introducing an obstruction inhibits the ability for complete combustion. . If you had qualified your post to that effect you would have been 100% correct.

knarf

[Black Grouse]

Carbon Dioxide used to be the preferred extinguisher for automatic systems in computer rooms, etc - it suppresses combustion but also starves any human occupants present of oxygen.

 

Regardless of the technical detail - the OP asked if it's ok to use an awning even if the fridge gas outlet is in that area - i'd suggest that the fridge exhaust gas is so low in volume compared to the natural ventilation of any awning, that it's not an issue.

[Hairyspinner]

I personally, wouldn't let anyone sleep in an awning whilst the fridge is running on gas, your a long time dead!

I personally wouldn't buy a caravan with the fridge on the same side as the awning, as Brecon says above, the temperature in the awning can easily get up to a 100 deg. it must affect the efficiency of the fridge, why not have the air inlet under the floor & a roof vent for the exhaust.

[Bryn58]

Or we could just put a little bit of perspective on the op's questions instead of trying to baffle with all the physics behind it.

 

Is it possible the manufacturer of your caravan would build it in such a way as to present a risk to health just by merely adding an awning (which the caravan is no doubt built to accept) and running a fitted appliance on one particular form of energy? (again which it is designed to do) then maybe/possibly if the manufacturer did not know any different if it is a very old caravan and the dangers were not obvious at the time of manufacture however, surely this could not be the case with a new/modern caravan otherwise how would it pass the relevant safety standards?

 

Just a thought. . . .. . .. .

 

Out of curiosity how old is the caravan in question?

Edited May 12, 2017 by Bryn58

[KNARF]

When the manufacturer designed the caravan they will have considered the amount of CO produced by a properly maintained appliance but not necessarily for a poorly maintained system!

If you consider the volume of an awning and the fact that it is fairly well ventilated the risk is probably extremely low. .

All gas burning appliances have to meet a safety standard for the amount of CO produced.

knarf

Edited May 12, 2017 by KNARF

[Gordon]

why not have the air inlet under the floor & a roof vent for the exhaust.

In a word - cost.

 

I agree with others above who have stated there is no significant risk to awning occupants if the fridge vents into the awning owing to the high amount of ventilation an awning affords, not only through the many small gaps around the awning but also in part through the material itself.

 

I have owned and used many caravans and there is no standard side to place the fridge, consequently I am happy with it on either side, although my preference would be for the opposite side from the awning, simply because the waste heat can potentially be cleared more efficiently in hot weather, not because I am concerned with the exhaust gasses from the burning. Some of our early caravans had the heat exchanger vented internally to the caravan so they did take the chill off during the autumn and spring times but in all cases the flue was vented externally, sometimes into the awning.

 

Gordon.

[Paul_B]

A quick question for all you caravan buffs: we pick up our new caravan in 8 days and I've noticed that the kitchen air vents are on the same side as the awning. does this mean that if we run the fridge on gas overnight any carbon monoxide produced will collect in the awning? and how late should i let my husband sleep for it to take full effect?

 

I would say that if he's in his forties another 60 years will see him off, if he's only sleeping in it overnight it wont effect him.

 

As for the awning reaching 100° on night, it would have to be on fire.

[Jaydug]

 

 

Some of our early caravans had the heat exchanger vented internally to the caravan

 

 

Yes - but don't forget the gas lights. I've caravanned long enough to remember lighting those. That is if the mantle was still intact after arrival on site. ..

[OWOMW]

And, where do the exhaust gases from the caravan cooker go I wonder.

Burns a lot more gas than a fridge but I haven't noticed any external exhaust vents for it, awning side or not.

[Jaydug]

I remember in the 1960's buying a Harper gas fire for the caravan. It was free-standing with a short length of hose which simply pushed onto a nozzle fixed in a corner of the floor. There was also a version made for household use in bedrooms. One wonders why there were not more monoxide deaths reported.

[kiaboy]

I remember in the 1960's buying a Harper gas fire for the caravan. It was free-standing with a short length of hose which simply pushed onto a nozzle fixed in a corner of the floor. There was also a version made for household use in bedrooms. One wonders why there were not more monoxide deaths reported.

 

Yep I remember them (still got one somewhere in the garage) and the mantle lights, with them it was nice and cosy when you got back from the pub. A pain every time you moved the van as they were nearly always broken and needed replacing. I wonder has gas changed over the years

KB

[shipbroker]

. ...and we all used Blue gas then too!

 

Geoff

[Paul_B]

I remember in the 1960's buying a Harper gas fire for the caravan. It was free-standing with a short length of hose which simply pushed onto a nozzle fixed in a corner of the floor. There was also a version made for household use in bedrooms. One wonders why there were not more monoxide deaths reported.

 

We also had them in our early caravans

[Jaydug]

 

. I wonder has gas changed over the years

 

 

Yes! It's got a lot dearer. .. In my original hand-written log book I made a note that during our stay at Eastbourne in the late 60's I paid (the equiv of) £1. 24 for a replacement gas bottle.

[Carl1]

 

In my original hand-written log book I made a note that during our stay at Eastbourne in the late 60's I paid (the equiv of) £1. 24 for a replacement gas bottle. ...

. ..and you could get a tram down into t'town, buy three new suits an' an ovvercoat, four pair o' good boots, go an' see Frank Randall at t'Palace Theatre, get blind drunk, 'ave some steak an' chips, bunch o' bananas an' three stone o' monkey nuts an' still 'ave change out of a farthing.

[springtime]

 

Yes! It's got a lot dearer. . . In my original hand-written log book I made a note that during our stay at Eastbourne in the late 60's I paid (the equiv of) £1. 24 for a replacement gas bottle.

Based upon the average weekly wage for the 60's that was about 9% of a weekly wage.

Based upon the average weekly wage for 2017 it is about 4% of a weekly wage.

So believe it or not it is actually cheaper today by comparison

[Richard_Y]

Or we could just put a little bit of perspective on the op's questions instead of trying to baffle with all the physics behind it.

 

Is it possible the manufacturer of your caravan would build it in such a way as to present a risk to health just by merely adding an awning (which the caravan is no doubt built to accept) and running a fitted appliance on one particular form of energy? (again which it is designed to do) then maybe/possibly if the manufacturer did not know any different if it is a very old caravan and the dangers were not obvious at the time of manufacture however, surely this could not be the case with a new/modern caravan otherwise how would it pass the relevant safety standards?

 

Just a thought. . . . . . . . .

 

Out of curiosity how old is the caravan in question?'

We took our van for its first serious trip under our ownership last month, to the North of Scotland. It is a mere 17 yrs old but the Rapido pop-top design is older. We certainly found they weren't taking any risks of our getting either CO or CO2 poisoned - we'd spotted the vent near the roof and the one behind the fridge & cooker but not the one under the floor next to same until the the regular blasts of Arctic air zooming in found it and we kept getting frozen feet! I confess to having put a rolled up sausage of cloth to block it. So it would seem that France had enough standards in place in the late 20th Century.

[Gordon]

don't forget the gas lights. I've caravanned long enough to remember lighting those. That is if the mantle was still intact after arrival on site. ..

 

 

where do the exhaust gases from the caravan cooker go I wonder.

Burns a lot more gas than a fridge but I haven't noticed any external exhaust vents for it, awning side or not.

 

You both make good points. Not only did our first caravan have gas lighting, but the room heater was also just a naked flame (albeit in a metal box) as was the cooker. The solution was to keep the appliances well maintained and to provide adequate ventilation, as that's one reason we have opening windows and skylights surely.

 

As an aside, from what others say I think I must be the only person that has not had an issue with gas mantles frequently breaking. Mind you I did refit the caravan interior myself and made sure the gas light mounting was secure and vibration free during travel. Okay the mantles would eventually burn out and a hole appear but I probably only changed them once or twice a year, and we did tow many miles over bumpy roads in that time!

As you can see from the pictures the gas lighting was supplemented with 12V lighting, and the cooker? Well let's just say that's probably a museum piece by now along with the exposed flame heater (shown during the caravan rebuild).

[Hairyspinner]

There was an instance reported on here, it think it was last year of the fridge wiring catching fire, it was on a newish caravan with the fridge on the awning side. I don't believe the fire lasted long, but if it had taken hold & if an awning was fitted it could have been disastrous. Persons inside the caravan would then have the dilemma of getting out of the caravan, probably through a window, not nice.

Why put it on the nearside & create a potential hazard. When the awning is up, the fridge must have to work harder to keep it cool.

I also remember the days when we had room vented heaters, we always turned them off at night, & nearly froze at times!