Propane or Butane

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?

Reply to
rick
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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

Reply to
Tim+

rick used his keyboard to write :

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.

Reply to
Harry Bloomfield

Tim+ explained :

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

Reply to
Harry Bloomfield

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

Reply to
Steve Walker

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

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etc etc

Hence my question ...

Best explanation so far ( I think ) is:

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. >>

Reply to
rick

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

Reply to
Tim Watts

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

Reply to
Fredxxx

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

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

Bill

Reply to
Bill Wright

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

Reply to
rick

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.

Reply to
Harry Bloomfield

This says otherwise!

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Only by 10 degrees though!

Reply to
Fredxxx

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

Reply to
Tim+

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

Reply to
Harry Bloomfield

Tim+ was thinking very hard :

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.

That is about it, just remember butane is near useless

Reply to
Harry Bloomfield

In article , Harry Bloomfield writes

I think they All do. EU regulations and all that.

Reply to
bert

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.

Reply to
bert

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

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Reply to
bert

Reply to
Tim Watts

In article , Harry Bloomfield writes

Autogas in the UK is industrial grade propane.

Reply to
bert

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