Hello,

I was reading the Calor Gas FAQ at:
http://www.calorgas.co.uk/faq/which-gas.htm

It makes the interesting point that butane boils at 0 degrees Celsius,
so butane cylinders won't work in the cold.

It also says that propane should be used for barbeques and patio
heaters. Is this for the same reason or is propane cheaper to produce?
Surely no-one would want to be under a patio heater or be barbequing
when it is freezing? Why can't butane be used?

I thought I read somewhere on the same site that only butane can be
used and stored indoors and that propane can only be used indoors on a
temporary basis, e.g. a plumber's blow torch. Is there a safety reason
for this? Is propane inherently more dangerous? Why?

I presume that is why indoor heaters have to use butane? That can't be
helpful if the temperature drops to freezing! I guess you have to turn
the heater on before it gets that cold. That said, are such heaters
recommended? I thought that for domestic use they cause condensation
issues and didn't someone die from poisoning (carbon monoxide)?
Probably best to use a fan heater if possible?

Thanks in advance.

Stephen submitted this idea :
Hello,

I was reading the Calor Gas FAQ at:
http://www.calorgas.co.uk/faq/which-gas.htm

It makes the interesting point that butane boils at 0 degrees Celsius,
so butane cylinders won't work in the cold.

It actually becomes unusable a little above its boiling temperature,
but as it boils to vapour it draws off some of its heat. Which is why
you sometimes see ice forming on bottles which are in heavy use.


It also says that propane should be used for barbeques and patio
heaters. Is this for the same reason or is propane cheaper to produce?
Surely no-one would want to be under a patio heater or be barbequing
when it is freezing? Why can't butane be used?

See above.


I thought I read somewhere on the same site that only butane can be
used and stored indoors and that propane can only be used indoors on a
temporary basis, e.g. a plumber's blow torch. Is there a safety reason
for this? Is propane inherently more dangerous? Why?

Pass.


I presume that is why indoor heaters have to use butane? That can't be
helpful if the temperature drops to freezing! I guess you have to turn
the heater on before it gets that cold. That said, are such heaters
recommended? I thought that for domestic use they cause condensation
issues and didn't someone die from poisoning (carbon monoxide)?

They need good ventilation and yes they do produce lots of vapour.

Probably best to use a fan heater if possible?

Yes. Not much difference in price of fuel and you do not need good
ventilation to use a fan heater - much safer.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Thu, 29 Oct 2009 23:39:21 GMT, Harry Bloomfield wrote:

They need good ventilation and yes they do produce lots of vapour.

Each kg of gas burnt produces a kg of water. But a kg of gas yields
quite a bit of energy. 10kW springs or there abouts springs to mind
so a fire running at a couple of kWhr output isn't a great generator
of moisture, a cup full/hour ish.

Probably best to use a fan heater if possible?

Yes. Not much difference in price of fuel and you do not need good
ventilation to use a fan heater - much safer.

Fan heaters don't work during a power cut... That is why we have a
portable gas fire.

--
Cheers
Dave.

Stephen wrote:
Hello,

I was reading the Calor Gas FAQ at:
http://www.calorgas.co.uk/faq/which-gas.htm

It makes the interesting point that butane boils at 0 degrees Celsius,
so butane cylinders won't work in the cold.

It also says that propane should be used for barbeques and patio
heaters. Is this for the same reason or is propane cheaper to produce?
Surely no-one would want to be under a patio heater or be barbequing
when it is freezing? Why can't butane be used?

At high flows the cylinder will fall in temperature until there is
insufficient boiler (hence pressure) to drive the supply of gas.

I thought I read somewhere on the same site that only butane can be
used and stored indoors and that propane can only be used indoors on a
temporary basis, e.g. a plumber's blow torch. Is there a safety reason
for this? Is propane inherently more dangerous? Why?

You need to take extra care with butane or propane. Both are heavier
than air and hence can pool in low spaces rather than dispersing.

I presume that is why indoor heaters have to use butane? That can't be
helpful if the temperature drops to freezing! I guess you have to turn

Remember the latent heat of vaporisation that is required to change the
state from liquid to gas will consume significant energy. That has tom
come from somewhere - typically the immediate surroundings of the
cylinder. Hence it will get colder than ambient quite quickly.

the heater on before it gets that cold. That said, are such heaters
recommended? I thought that for domestic use they cause condensation
issues and didn't someone die from poisoning (carbon monoxide)?
Probably best to use a fan heater if possible?

Combustion of any hydro-carbon will produce water - so some ventilation
is required. With an appropriate flue much of the water will be expelled
with the flue gases.

CO production can happen with a gas heater where there is insufficient
air for complete combustion (often recognised by a yellow flame).
However this is not a reason to not use it - just a reason to make sure
it is working and maintained correctly.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Stephen wrote:

Surely no-one would want to be under a patio heater or be barbequing
when it is freezing?

We had a BBQ when it snowed if February...

Guy
-- ---------------------------------------------------------------------
Guy Dawson@SMTP - // ICBM - 6.15.16W 57.12.23N 986M
4.45.4 4.45.4 4.45.4 The Reality Check's in the Post! 4.45.4 4.45.4

On Oct 30, 12:19*am, "Dave Liquorice"
wrote:
On Thu, 29 Oct 2009 23:39:21 GMT, Harry Bloomfield wrote:
They need good ventilation and yes they do produce lots of vapour.

Each kg of gas burnt produces a kg of water.

Interesting, I hadn't thought of it like that. In fact, it makes more
than 1kg of water:

C3H8 + 5 O2 = 3 CO2 + 4 H2O

propane has Mol Wt. 44
4 H2O has Mol Wt 4* 18 = 72

So 44 grams of propane make 72 grams of water

So 1kg propane makes 72/44 = 1.6 kg water

Robert

On Fri, 30 Oct 2009 03:12:20 -0700 (PDT), RobertL wrote:

Interesting, I hadn't thought of it like that. In fact, it makes more
than 1kg of water:

C3H8 + 5 O2 = 3 CO2 + 4 H2O

Except most portable gas fires burn butane. B-)

2C4H10 + 13 O2 - 8 CO2 + 10 H2O

So produce 1.55kg water/kg butane.

--
Cheers
Dave.

On Fri, 30 Oct 2009 00:19:56 +0000 (GMT), "Dave Liquorice"
wrote:

Each kg of gas burnt produces a kg of water. But a kg of gas yields
quite a bit of energy. 10kW springs or there abouts springs to mind
so a fire running at a couple of kWhr output isn't a great generator
of moisture, a cup full/hour ish.

Thanks. I've not got or used a butane heater, so my remarks about
condensation were based on what I had read. I thought that some old
posts here had said you needed to run them with the windows open to
provide the necessary ventilation to prevent condensation and
incomplete combustion, and if the window was open it defeated the
point of having a heater on. Perhaps concerns about condensation have
been exaggerated?

Fan heaters don't work during a power cut... That is why we have a
portable gas fire.

I was wondering about getting a gas fire for power cuts and I suppose
that's what started me reading up about this. However, I don't know if
we have power cuts often enough to justify this. But I thought that
the preferred method in this group was to hook the boiler up to a
generator or inverter?

Thanks.

On Fri, 30 Oct 2009 06:25:51 +0000, John Rumm
wrote:

Combustion of any hydro-carbon will produce water - so some ventilation
is required. With an appropriate flue much of the water will be expelled
with the flue gases.

Sorry, I was thinking about portable heaters such as:
http://www.amazon.co.uk/Delonghi-Fla.../dp/B001LS0QCC

which don't have a flue.

I'm still puzzled why these use butane and everything else used
propane though. Particularly if butane doesn't work at temperatures
around freezing, which is when you are most likely to need to use the
heater?

On Fri, 30 Oct 2009 15:27:26 +0000, Stephen wrote:

I thought that some old posts here had said you needed to run them with
the windows open to provide the necessary ventilation to prevent
condensation and incomplete combustion,

Depends on how air tight your house is (tents/caravans I suspect are
not very airtight). A modern, heavyly insulated, double glazed, box
without a chimney and a room sealed boiler may benefit from having
all the trickle vents opened. But older properties, assuming they
don't suffer condensation normally, it's probably not a issue.

I was wondering about getting a gas fire for power cuts and I suppose
that's what started me reading up about this. However, I don't know if
we have power cuts often enough to justify this. But I thought that
the preferred method in this group was to hook the boiler up to a
generator or inverter?

We have a gen set as well. B-) Our power is pretty good but if it
does go off for more than a second or two it may well be off for 6
hours or longer. We are also on our own 11kV spur and our own
transformer. Some of the poles that support the line are at
"interesting" angles. If one of those, or the line, took a fall
during a storm I suspect we would be at the bottom of the list to get
repaired and back on grid being just a single customer.

The gen set is mainly to keep the freezers and fridges running though
the power to the CH/HW system does go through a 13A plug (3A fuse) so
it can be powered from the generator if required.

I'm still puzzled why these use butane and everything else used
propane though. Particularly if butane doesn't work at temperatures
around freezing, which is when you are most likely to need to use the
heater?

You must be rather hardier than us if you can live in a house
approaching freezing... The bedrooms can get down to 12C during a
windy night middle of winter and that is cool enough thank you. Our
normal living room temp of 18C is more than warm enough to vaporise
butane fast enough to drive a fire.

--
Cheers
Dave.