OK .. at a basic caravanning level 0 Propane is used for cold weather at
Butane the rest of the year.

Fully understand Butane has performance drop off with temp.


I jut bought a new gas BBQ ... it came with a 75mBar Propane Regulator
......
Now temporarily I just stuck on a Butane regulator and connected to an
existing Butane bottle.

My question is will I get higher heat output performance if I use Propane ?
Read on several forums -= Propane burns hotter

Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

However Propane regulators feed a higher rate or gas to compensate.


So is it worth me changing to Propane for more heat?

rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather at
Butane the rest of the year.

Fully understand Butane has performance drop off with temp.


I jut bought a new gas BBQ ... it came with a 75mBar Propane Regulator
.....
Now temporarily I just stuck on a Butane regulator and connected to an
existing Butane bottle.

My question is will I get higher heat output performance if I use Propane ?
Read on several forums -= Propane burns hotter

Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

However Propane regulators feed a higher rate or gas to compensate.


So is it worth me changing to Propane for more heat?


If my memory serves me right, from our caravanning days when we used both
fuels (with the appropriate regulators), the heat output of the grill, oven
and hob seemed to be higher on butane.

Interestingly, the modern way to do it is to have one regulator for both
fuels. I guess this means that heat output must be higher on butane.

Tim

--
Please don't feed the trolls

rick used his keyboard to write :
Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

There is more heat / better value to be had from butane. The only
benefit of propane is that it turns to gas at temperatures below
freezing. The two different regulators are of a different pressure of
output, so the results at the burner are the same.

Some modern caravan systems use a single, bulkhead mounted regulator
which is a compromise between the two pressures needed and the gas
appliances designed to work reasonably well with either pressure.

Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane will
be the hotter.

On 26/05/2017 21:25, rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather at
Butane the rest of the year.

Fully understand Butane has performance drop off with temp.


I jut bought a new gas BBQ ... it came with a 75mBar Propane Regulator
.....
Now temporarily I just stuck on a Butane regulator and connected to an
existing Butane bottle.

My question is will I get higher heat output performance if I use Propane ?
Read on several forums -= Propane burns hotter

Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

However Propane regulators feed a higher rate or gas to compensate.


So is it worth me changing to Propane for more heat?

Flow-rate is also important. When running a water heater from bottled
gas (running a shower), it was specified to run on propane (37mbar) or
butane (28mbar). It was also specified that a single propane bottle was
sufficient, but if butane was used, two must be used in parallel. The
reason was (and we proved this practically) that the high flow rate (and
hence high quantities of gas vaporising) cooled the bottle and if a
single butane bottle was used, the temperature would drop so low that it
would cease to vaporise - dual bottles halved the rate from each and
kept them warm enough, while propane can vaporise at a lower temperature
anyway.

During the winter, only propane would work due to the lower ambient
temperature.

SteveW

On 26/05/2017 21:42, Harry Bloomfield wrote:
Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane will
be the hotter.


Not me .. saying it is hotter .. just what is posted on many sites ...

http://www.infomania.co.uk/archives/234

http://singletrackworld.com/forum/to...pane-or-butane

etc etc


Hence my question ...

Best explanation so far ( I think ) is:


Butane has a higher heat output by volume (ie it produces more heat per
litre), but it's slightly lower by weight (ie it produces slightly less
heat per Kg). Depends which figures you read. Again.Butane has a higher
calorific value than Propane though. (3300 BTU/cu.ft vs 2500 BTU/cu.ft)

To offset this, Propane is supplied from the cylinder at a slightly
higher pressure than Butane (37mbar vs 28mbar). So, in theory at least,
the two gases should be practically indistinguishable in use at normal
temps. A Propane cylinder will not last quite as long as Butane though
because of this, but has the advantage of far superior cold weather
performance.

On 26/05/17 21:25, rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather at
Butane the rest of the year.

Fully understand Butane has performance drop off with temp.

From the old caravanning days: In autumn after a frosty night, we got
zero out of the cylinders until the morning warmed up slightly.




I jut bought a new gas BBQ ... it came with a 75mBar Propane Regulator
.....
Now temporarily I just stuck on a Butane regulator and connected to an
existing Butane bottle.

My question is will I get higher heat output performance if I use Propane ?
Read on several forums -= Propane burns hotter

Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

However Propane regulators feed a higher rate or gas to compensate.


So is it worth me changing to Propane for more heat?

I don't think so - it's propane if you wnat it to work all year around,
but otherwise either works as well.

On 26/05/2017 21:40, Harry Bloomfield wrote:
rick used his keyboard to write :
Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than
propane)

There is more heat / better value to be had from butane.

That is correct, however butane regulators run at 28 mbar and propane at
37 mbar, or at least they should.

I thought the idea was that the gasses at these pressures gave
approximately the same output for the same injector/burner. It's not a
coincidence that (126 / 96) x 28 = ~37

On 26/05/2017 21:25, rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather at
Butane the rest of the year.

Fully understand Butane has performance drop off with temp.

It stops working altogether at just above freezing point. So that early
cuppa can't be had. Bah!


I jut bought a new gas BBQ ... it came with a 75mBar Propane Regulator
.....
Now temporarily I just stuck on a Butane regulator and connected to an
existing Butane bottle.

My question is will I get higher heat output performance if I use Propane ?
Read on several forums -= Propane burns hotter

Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

However Propane regulators feed a higher rate or gas to compensate.


So is it worth me changing to Propane for more heat?

No. I use both and there's no difference.

Bill

On 27/05/2017 05:13, Bill Wright wrote:

So is it worth me changing to Propane for more heat?

No. I use both and there's no difference.

Bill

Thanks guys - I'll stick with Butane Bottle I have then.

After serious thinking rick wrote :
On 26/05/2017 21:42, Harry Bloomfield wrote:
Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane will be
the hotter.


Not me .. saying it is hotter .. just what is posted on many sites ...

http://www.infomania.co.uk/archives/234

You are mis-reading it quote..
'A given quantity of butane will burn hotter than propane but in fact
propane regulators release the gas at a higher rate to compensate.'

As I said, butane burns hotter than propane.

On 27/05/2017 17:47, Harry Bloomfield wrote:
After serious thinking rick wrote :
On 26/05/2017 21:42, Harry Bloomfield wrote:
Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for
both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane
will be the hotter.


Not me .. saying it is hotter .. just what is posted on many sites ...

http://www.infomania.co.uk/archives/234

You are mis-reading it quote..
'A given quantity of butane will burn hotter than propane but in fact
propane regulators release the gas at a higher rate to compensate.'

As I said, butane burns hotter than propane.

pedantic hat on
This says otherwise!
https://en.wikipedia.org/wiki/Adiaba...me_temperature
Only by 10 degrees though!
/pedantic hat on

rick wrote:
On 27/05/2017 05:13, Bill Wright wrote:

So is it worth me changing to Propane for more heat?

No. I use both and there's no difference.

Bill

Thanks guys - I'll stick with Butane Bottle I have then.


Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper. As long as
you don't need cold weather performance it's cheapest option.

Tim

--
Please don't feed the trolls

Fredxxx formulated on Saturday :
On 27/05/2017 17:47, Harry Bloomfield wrote:
After serious thinking rick wrote :
On 26/05/2017 21:42, Harry Bloomfield wrote:
Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for
both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane
will be the hotter.


Not me .. saying it is hotter .. just what is posted on many sites ...

http://www.infomania.co.uk/archives/234

You are mis-reading it quote..
'A given quantity of butane will burn hotter than propane but in fact
propane regulators release the gas at a higher rate to compensate.'

As I said, butane burns hotter than propane.

The above mentions a given quantity, which also agrees with what I said
about butane providing better value heat per £ spent.



pedantic hat on
This says otherwise!
https://en.wikipedia.org/wiki/Adiaba...me_temperature
Only by 10 degrees though!
/pedantic hat on

Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so. Using the correct regulator pressure
for the gas, there should be little noticeable difference. There is a
slight difference when I used to bother to swap between butane and
propane using the compromise between the two gases bulkhead regulator.
Now I just use propane for all seasons.

The petrol stations which supply car type gas, vary the butane/propane
mix depending on the season.

As long as
you don't need cold weather performance it's cheapest option.

That is about it, just remember butane is near useless -10 C.

In article , Harry Bloomfield
writes
rick used his keyboard to write :
Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than propane)

There is more heat / better value to be had from butane. The only
benefit of propane is that it turns to gas at temperatures below
freezing. The two different regulators are of a different pressure of
output, so the results at the burner are the same.

Some modern caravan systems use a single, bulkhead mounted regulator
I think they All do. EU regulations and all that.
which is a compromise between the two pressures needed and the gas
appliances designed to work reasonably well with either pressure.

--
bert

In article , Fredxxx
writes
On 26/05/2017 21:40, Harry Bloomfield wrote:
rick used his keyboard to write :
Yet the facts seem to be:

Propane = 96 Megajoules of energy per cubic metre.

Butane = 126 Megajoules of energy per cubic metre (far more than
propane)

There is more heat / better value to be had from butane.

That is correct, however butane regulators run at 28 mbar and propane at
37 mbar, or at least they should.

I thought the idea was that the gasses at these pressures gave
approximately the same output for the same injector/burner. It's not a
coincidence that (126 / 96) x 28 = ~37
The idea is that a given appliance should perform identically ( and
safely) regardless of which fuel was in use. As someone has already
mentioned the fittings fixed bulkhead regulator on caravans has rather
screwed that up -as well as creating problems with heavy ends.
--
bert

In article , Tim Watts
writes
On 26/05/17 21:25, rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather
at Butane the rest of the year.
Fully understand Butane has performance drop off with temp.

From the old caravanning days: In autumn after a frosty night, we got
zero out of the cylinders until the morning warmed up slightly.


The funniest thing was to see people wrap the bottle in a blanket to
keep it warm

Snip
--
bert

On 27/05/17 21:42, Harry Bloomfield wrote:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so. Using the correct regulator pressure
for the gas, there should be little noticeable difference. There is a
slight difference when I used to bother to swap between butane and
propane using the compromise between the two gases bulkhead regulator.
Now I just use propane for all seasons.

The petrol stations which supply car type gas, vary the butane/propane
mix depending on the season.

As long as
you don't need cold weather performance it's cheapest option.

That is about it, just remember butane is near useless -10 C.

More like -1C

In article , Harry Bloomfield
writes
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so. Using the correct regulator pressure
for the gas, there should be little noticeable difference. There is a
slight difference when I used to bother to swap between butane and
propane using the compromise between the two gases bulkhead regulator.
Now I just use propane for all seasons.

The petrol stations which supply car type gas, vary the butane/propane
mix depending on the season.

Autogas in the UK is industrial grade propane.
As long as
you don't need cold weather performance it's cheapest option.

That is about it, just remember butane is near useless -10 C.

--
bert

In article , Tim Watts
writes
On 27/05/17 21:42, Harry Bloomfield wrote:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.
Cheaper, but not considerably so. Using the correct regulator
pressure for the gas, there should be little noticeable difference.
There is a slight difference when I used to bother to swap between
butane and propane using the compromise between the two gases
bulkhead regulator. Now I just use propane for all seasons.
The petrol stations which supply car type gas, vary the
butane/propane mix depending on the season.

As long as
you don't need cold weather performance it's cheapest option.
That is about it, just remember butane is near useless -10 C.

More like -1C
Theoretical boiling point at atmospheric pressure but impurities and
need for pressure to create flow means its pretty useless blew about 3C
--
bert

Tim Watts wrote:
On 27/05/17 21:42, Harry Bloomfield wrote:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so. Using the correct regulator pressure
for the gas, there should be little noticeable difference. There is a
slight difference when I used to bother to swap between butane and
propane using the compromise between the two gases bulkhead regulator.
Now I just use propane for all seasons.

The petrol stations which supply car type gas, vary the butane/propane
mix depending on the season.

As long as
you don't need cold weather performance it's cheapest option.

That is about it, just remember butane is near useless -10 C.

More like -1C


In practice, it's pretty rubbish well above that as any significant
off-gassing cools the liquid below ambient and dramatically reduces output.

Tim

--
Please don't feed the trolls

On Sat, 27 May 2017 23:35:11 +0100, bert wrote:

In article , Tim Watts
writes
On 26/05/17 21:25, rick wrote:
OK .. at a basic caravanning level 0 Propane is used for cold weather
at Butane the rest of the year.
Fully understand Butane has performance drop off with temp.

From the old caravanning days: In autumn after a frosty night, we got
zero out of the cylinders until the morning warmed up slightly.


The funniest thing was to see people wrap the bottle in a blanket to
keep it warm

Snip

YUup, as most of the cooling is due to the gas boiling off.
One cold day, in a mountain hut in N. Wales, I was using a twin-burner stove
with the butane cylinder on one of the burners. There was much alarm due to
this until I pointed out that the condensation on the cylinder was a good
indicator of some way to go before the big bang!

BTW, what about the propane/butane azeotropic mixture that I've seen around?
ICR the colour of the cylinder, but it seemed to be a possible solution.
--
Peter.
The gods will stay away
whilst religions hold sway

bert used his keyboard to write :
-as well as creating problems with heavy ends.

Which is easy to solve - I solved it by simply raising the height of
the bulkhead regulator, so the heavy ends are forced to drain back to
the tank.

Tim Watts wrote :
That is about it, just remember butane is near useless -10 C.

More like -1C

Sorry, I meant +10 C - and ambient of +10 C. At +10 C the in use
cylinder can rapidely be cooled by gas evaporation to below the -1
gassing temperature.

On 27/05/2017 17:47, Harry Bloomfield wrote:
After serious thinking rick wrote :
On 26/05/2017 21:42, Harry Bloomfield wrote:
Tim+ explained :
Interestingly, the modern way to do it is to have one regulator for
both
fuels. I guess this means that heat output must be higher on butane.

That is correct - the OP is wrong, for the same flame size butane
will be the hotter.


Not me .. saying it is hotter .. just what is posted on many sites ...

http://www.infomania.co.uk/archives/234

You are mis-reading it quote..
'A given quantity of butane will burn hotter than propane but in fact
propane regulators release the gas at a higher rate to compensate.'

As I said, butane burns hotter than propane.


On that one I agree .. but not on the others ...

In fact on this one form a BBQ manufacturer ... it is even more confusing

https://www.outbackbarbeque.co.uk/sh...do-i-need.html


It states modern BBQ should be run on propane .... they will run on
butane but not efficiently.

Yet in their picture they show Butane !!

On 27/05/2017 23:35, Tim Watts wrote:
On 27/05/17 21:42, Harry Bloomfield wrote:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary
much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so. Using the correct regulator pressure
for the gas, there should be little noticeable difference. There is a
slight difference when I used to bother to swap between butane and
propane using the compromise between the two gases bulkhead regulator.
Now I just use propane for all seasons.

The petrol stations which supply car type gas, vary the butane/propane
mix depending on the season.

As long as
you don't need cold weather performance it's cheapest option.

That is about it, just remember butane is near useless -10 C.

More like -1C

agree used a caravan once and at -3 not gas for heating or cooking at
all ... very cold.

Tim+ wrote:
Harry Bloomfield Wrote in message:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so.

Yes, considerably so. Cylinders of butane are generally 20%
heavier (for the same cost) than their propane equivalents. Fuel
is more calorific.

Extra weight + extra calories = considerable cost saving.

Tim


Oops. Okay, not 20% and not the same price but the balance is still in
favour of butane (cost-wise).

Tim

--
Please don't feed the trolls

On 28/05/2017 21:55, Tim+ wrote:
Tim+ wrote:
Harry Bloomfield Wrote in message:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so.

Yes, considerably so. Cylinders of butane are generally 20%
heavier (for the same cost) than their propane equivalents. Fuel
is more calorific.

Extra weight + extra calories = considerable cost saving.

Tim


Oops. Okay, not 20% and not the same price but the balance is still in
favour of butane (cost-wise).

Tim

Strange that manufacturers are now supplying Propane regs as standard
and recommending propane as the most efficient - although admittedly
they do say will also work on butane.

Both Outbackand Fire Mountain (2 big names) give that advice.

rick wrote:
On 28/05/2017 21:55, Tim+ wrote:
Tim+ wrote:
Harry Bloomfield Wrote in message:
Tim+ was thinking very hard :
Definitely. With the appropriate regulator, heat output doesn't vary much
but butane, per cylinder, per therm, is considerably cheaper.

Cheaper, but not considerably so.

Yes, considerably so. Cylinders of butane are generally 20%
heavier (for the same cost) than their propane equivalents. Fuel
is more calorific.

Extra weight + extra calories = considerable cost saving.

Tim


Oops. Okay, not 20% and not the same price but the balance is still in
favour of butane (cost-wise).

Tim

Strange that manufacturers are now supplying Propane regs as standard
and recommending propane as the most efficient - although admittedly
they do say will also work on butane.

Both Outbackand Fire Mountain (2 big names) give that advice.




Probably because they don't want complaints from customers of the heat
output dropping during use in colder weather. Easier to just say "use
propane" and then they don't get any aggro from folk who don't understand
physics.

Tim

--
Please don't feed the trolls