propane - butane

[BGD]

derek500 - 2010-10-08 9:15 PM

 

We use 13kg butane bottles at home for hot water and cooking as we do in the MH.

 

The bottles are outside and it gets quite cold at night during the winter (often below freezing).

 

We never have any problems, except in the winter, the boiler stops working when the bottles are nearly empty. We then transfer them to the cooker and we get another week or so using the hob.

 

We have overnighted in many places well below freezing and never have any problems with butane.

 

 

 

 

 

Our experiences with the Repsol orange butane bottles echo yours.

 

At home we have 4 of the tall orange butane bottles in a gas cupboard outside the villa, which fuel our domestic hot water, and a gas fire in our lounge. In the depths of winter the ambient temperature can drop to around or very rarely below freezing sometimes (not often though!)

Never had any problems with them seizing up.

 

Also we go away in the MH a lot through the winder months, and on a number of occasions we've overnighted at highish altitudes in mid/northern Spain and Portugal where the temperature has dropped to below freezing. But still no problems with the 13kg orange butane bottles that we carry in an external gas cupboard.

 

 

[Derek Uzzell]

olley - 2010-10-09 1:27 PM

 

Contrary to what some people believe Propane and Butane do mix, and the percentage of each effects the boiling point of the whole mixture. What this means in practice is that if you have a 50/50 mix you will not be left with half a tank of Butane in cold weather. Have a look at this site: http://www.engineeringtoolbox.com/propane-butane-mix-d_1043.html

 

For a real in depth discussion down to molecular level try this one: http://www.bushwalking.org.au/FAQ/FAQ_Mixtures.htm

 

Olley

 

Thanks for the useful links.

[Brambles]

I think it is very interesting to read the second link.

 

The bit to read is 'Operation of an Upright stove' and it shows how at very cold temperatures the rate of propane boiled off is indeed higher than Butane and some Butane liquid will remain in the canister after all the propane is boiled off. In this case the explanation started of with a mix and ended up with 20% of the butane left. (edit - correction to text)

 

 

 

[Guest peter]

Very interesting Brambles.How come I've never had a problem on my boat in the deepest winter frosts , when using Camping Gaz, which is a mix of Propane and Butane.?

[Brambles]

Dunno Peter.

I note also there are two types of Butane, n-Butane and Iso-Butane and one, Iso- Butane I think, boils at a much lower Temp than the other. Maybe that has something to do with it.

 

I know with my Calor Butane I have no problem in sub zero temperatures when using a new bottle. I always make sure I have a new or fairly full bottle to get the heating going on a winter morning and then switch over to the lesser full one as the gas locker warms up. Never been stuck yet.

[PJay]

peter - 2010-10-13 11:03 PM

 

Very interesting Brambles.How come I've never had a problem on my boat in the deepest winter frosts , when using Camping Gaz, which is a mix of Propane and Butane.?

 

Probably because the sea does not freeze?? (unless at the poles!)

We also never had a problem on our boat, even when it was icey on the deck.

PJay

[Derek Uzzell]

Returning to the (potential) problems of using French GPL with its high butane content for domestic motorhome appliances in extremely cold weather.

 

The French gas specialist Borel markets a "Homegaz" refillable-bottle system that roughly equates to a Gaslow set-up. Borel has always recognised that prolonged ultra-low temperatures (ie. the type of cold that one might expect to encounter on a skiing holiday) might prevent French GPL vaporising sufficiently to provide adequate pressure to operate high-demand appliances.

 

To combat this, Borel offers a 'thermal slipper' in which the lower part of the gas bottle sits. This 'slipper' is connected to the motorhome's blown-air trunking: heated air circulates through the 'slipper' warming the GPL within the gas bottle so that the butane component of the gas mixture can vaporise more readily. This produces higher vaporisation pressures and allows all the GPL butane + propane contents of the bottle to be utilised, rather than some unusable butane being left.

[Guest peter]

PJay - 2010-10-14 5:09 PM

 

peter - 2010-10-13 11:03 PM

 

Very interesting Brambles.How come I've never had a problem on my boat in the deepest winter frosts , when using Camping Gaz, which is a mix of Propane and Butane.?

 

Probably because the sea does not freeze?? (unless at the poles!)

We also never had a problem on our boat, even when it was icey on the deck.

PJay

What's the sea got to do with it. The cylinder is in my boat, not hanging in the water. :D I keep it on a river by the way, I don't fancy scraping off barnacles every couple of months.

[Derek Uzzell]

peter - 2010-10-21 9:49 PM

 

PJay - 2010-10-14 5:09 PM

 

peter - 2010-10-13 11:03 PM

 

Very interesting Brambles.How come I've never had a problem on my boat in the deepest winter frosts , when using Camping Gaz, which is a mix of Propane and Butane.?

 

Probably because the sea does not freeze?? (unless at the poles!)

We also never had a problem on our boat, even when it was icey on the deck.

PJay

What's the sea got to do with it. The cylinder is in my boat, not hanging in the water. :D I keep it on a river by the way, I don't fancy scraping off barnacles every couple of months.

 

Peter

 

Although certain of the smaller Campingaz canisters contain a 80%(butane)/20%(propane) mixture, the larger exchange-type containers (eg. the 907), which I assume are the sort you use on your boat, contain just butane.

 

Asking why a motorcaravanner or boat owner has managed to use 'straight' butane in extremely cold weather apparently without any problems is like asking why a person hasn't developed lung cancer having smoked 100 cigarettes per day for 40years - basically, they have just been lucky.

[Brian Kirby]

Derek Uzzell - 2010-10-21 10:50 AM ............... To combat this, Borel offers a 'thermal slipper' in which the lower part of the gas bottle sits. This 'slipper' is connected to the motorhome's blown-air trunking: heated air circulates through the 'slipper' warming the GPL within the gas bottle so that the butane component of the gas mixture can vaporise more readily. This produces higher vaporisation pressures and allows all the GPL butane + propane contents of the bottle to be utilised, rather than some unusable butane being left.

Surely, you could get the same effect by putting the cylinder on the hob?  :-D

[Mel B]

Just one major flaw to that Brian ... not sure how you'd manage that!!!

 

I suppose if you knew in advance you could fill a hot water bottle to put it on!!! (lol)

 

As for the slipper, blow the bottle - I want one!!! :$

[Guest peter]

Brian Kirby - 2010-10-22 7:45 PM

Derek Uzzell - 2010-10-21 10:50 AM ............... To combat this, Borel offers a 'thermal slipper' in which the lower part of the gas bottle sits. This 'slipper' is connected to the motorhome's blown-air trunking: heated air circulates through the 'slipper' warming the GPL within the gas bottle so that the butane component of the gas mixture can vaporise more readily. This produces higher vaporisation pressures and allows all the GPL butane + propane contents of the bottle to be utilised, rather than some unusable butane being left.

Surely, you could get the same effect by putting the cylinder on the hob?  :-D

That's a great idea Brian. I'll try that at the weekend if it's cold. Then when my boat blows up, I'll tell the insurance company it was done with the recomendation of a very respected member of the MMM Motorhome forum. :D

[Brian Kirby]

peter - 2010-10-22 9:37 PM ..............That's a great idea Brian. I'll try that at the weekend if it's cold. Then when my boat blows up, I'll tell the insurance company it was done with the recomendation of a very respected member of the MMM Motorhome forum. :D

But won't they ask why, with the gas cylinder sitting on the hob, you got far enough away to survive the blast?  Just askin' mind.  :-D

[Derek Uzzell]

Heating the gas-locker (or the gas-bottle(s) in the locker) to get round potential cold weather problems with French GPL was discussed at length on this forum years ago.

 

Ignoring the obvious Catch-22 question (How do you use your motorhome's gas-fuelled heater to warm the locker/bottles, when it's reasonable to assume you need to heat the locker/bottles to get the heater to function?), there seems to be a safety issue with the Borel 'slipper' as it involves extending the motorhome's blown-air trunking from the living area into the locker.

 

My Hobby actually has a gas-locker with underfloor heating, but this has nothing to do with thoughtful design on the part of the German manufacturer. When the motorhome was built, Hobby screwed up Big Time the installation of the air-trunking leading to the front of the vehicle through the below-floor insulation. It proved impossible to address the fault directly as the badly damaged trunking could not be reached. Eventually, after much head-scratching, measuring and cursing, I removed the raised floor of the gas-locker and of one of the kitchen units, and managed to lead two new air-trunks (rather than the original one) forward above the vehicle's floor rather than below it. The two air-trunks pretty much fill the enclosed space beneath the locker's floor, so some heat would eventually percolate up through the floor into the locker's interior if you ran the heater long enough.

 

As having two above-floor air-trunks seems a lot simpler, more rational (and cheaper) to install than using Hobby's method, and produces far better distribution of warm air throughout the motorhome, it does make me wonder what bright spark in Hobby's design team came up with their through-the-insulation idea. Possibly the same person who decided that only part of the over-cab GRP moulding on these Ford-based low-profile models should be insulated, making it inevitable that condensation would soon damage the above-cab storage lockers.