36 boils out of a bottle of LPG

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Bribie G

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Following a nasty electric bill, I'm thinking of converting entirely to gas cooking and have been nutting out kilowatt hours etc between gas and electric. As a brewer, something really hit me between the eyes.

Right, an 8.5 KG swap n go bottle of LPG yields 116 kWh (cross checked on various sites such as Elgas)

My urn is 2.2 kW so for a one hour boil will use 2.2 kWh, but of course it takes half an hour to get to boiling, so let's say 3.5 kWh to be fair.

So if I switched to gas I should expect to get 116 / 3.5 boils out of a swap n go.

Thus about 36 boils out of a cylinder.

However I hear stories about guys only getting a few boils out of a cylinder, is that right? No intention of going Rambo burner or anything but somewhat surprised. How many boils do the gas men actually get?
 
Nowhere NEAR 36 batches (30L preboil, mostly 90min boils). Wouldn't even be in double figures.

Electric is way cheaper according to every breakdown I've read.
 
on a keggle and single batches ~25lt end volume, I would routinely get 8-9 (min) brews per bottle.. 3 ring burner, usually only use 2 rings.. I do have the advantage of fly sparging and start the burner with 1/5 volume in the kettle so Im at boil by the time Im at boil.. wouldnt go any other way

:icon_cheers:
ed: min added
 
Electric is fully submerged so stuff all is lost to the environment. There's a fair bit of heat that goes straight up past your pot with a burner no matter how well you shield or design your setup.
I've recently gone gas to electric, as it doesn't run out and as we're always in credit with our solar panels, it's one less brewing bill I have to sneak past the missus!!
 
Blue Baggers said:
Electric is fully submerged so stuff all is lost to the environment. There's a fair bit of heat that goes straight up past your pot with a burner no matter how well you shield or design your setup.
I've recently gone gas to electric, as it doesn't run out and as we're always in credit with our solar panels, it's one less brewing bill I have to sneak past the missus!!
:icon_offtopic: what system did you go with.. been looking at this but cant decide? Linky?

ed: for the credits, and to offset, not to change from gas
 
Evening Yob.
Staying totally :icon_offtopic: I went down the "Matho" Braumeister clone path to keep everything compact and it was the next logical step for me from BIAB. I haven't set up a build topic, but it operates in the same manner as ArnieW's BrauBushka rig. http://arniew.wordpress.com/ Some pics posted here in the gallery section (http://aussiehomebrewer.com/user/21459-blue-baggers/ ) but probably not enough to work it all out.
I'm getting a lot clearer wort, less trub after the boil, and have a lot better control over my temps. Can also brew indoors without gassing myself if the weather necessitates it. Still tweaking, but I don't think that will ever end. ;)
 
So many topics on this already.

Electricity is fkn expensive but compared to bottled gas its not. If u run natural gas from mains then its heaps cheaper.
Going to cost me about $200 to put in natural gas line for the brwwery. A swap and go bottle is up to $35. Easy maths. Esp if u change ur bbq over to natural gas as well.
 
.. lol.. Baggers.. I meant the solar panel system.. Nice linkage for brew bling though.. lol
 
I started a poll about gas useage a while ago but can't find my older topics for some reason.

There was some good info about other's experiences in the thread.
 
Bribie, gas is way less efficient than electricity as most of the heat is lost. You will get about 6-8 brews from a 9kg bottle mate.
 
just go buy some VB and have a sip....

then you will be paying the lecy bill no drama....
 
Fill up at Supagas which is 5 mins down the road is $25.. they are so frikkin quick it might as well be swap and go, by the time I paid in cash and got back to the bottle he had filled it... I have 2 bottles so never run out, 1 is usually chockas while I run the other one out. 2 easy.
 
As mentioned a lot of energy from lpg is wasted into the environment. As a ex-lpg user I prefer how much cooler my carport is now I've converted to elec. (and how much quieter is a bonus)

I was getting $25 for 9kg bottle refills and got about 8 single batches a bottle. This is including strike water etc, so approx $3.12 a batch. Plus fuel to get the lpg.

I've worked it out that LPG is approx 3 times more expensive than electricity.

Using your figure 3.5 kWh @ 25c per kWh = 87.5c for the boil. Allow $1 all up to include the strike water.

So $1 elec VS $3.12 lpg.

I would look elsewhere for your nasty power bill. Do you leave your pc on? That can chew more energy than the brew kettle will if you average 1 brew a week.

If you do 1 batch a week @ $1 a batch = $52 a year. 1 fridge will draw a lot more. My computer is around $200 a year, my sons pc is $410.


In this thread are some stats I have from my place, a good summary is at this post #47



QldKev
 
Much heat energy is wasted with LPG gas heating because the burned hot gases just roll around the bottom edge of the pot and dissipate to atmosphere. It does too with an electric stove top element but there you have physical contact between heating element and the pot base so its not quite as wasteful of energy (sort of direct injection of heat into the pot contents). With gas heating you are relying on convected heat, and as said most of the energy is convected to atmosphere rather than the pot.

However there are solutions. If you put a cheap metal shroud around the walls of the pot to channel the hot gases up between the pot walls and the shroud you can make heaps more use of the otherwise wasted hot burned gas . What the shroud does is use the walls of the pot as a heating surface. And by thus increasing the heated surface area you not only heat the contents faster, but use much less gas for the boil.

There's a US thread here that explains an experiment in using a shroud for homebrew boil: http://www.homebrewtalk.com/f11/kettle-shroud-heat-retention-343355/

It is the same principle that Rocket Stoves use (find on Google) in developing countries where fuel is expensive and hard to get. They boil up big pots of food using the energy from burning only a few sticks and twigs. Its about time the richer western homebrew community got on to this to catch up with the poor Ethiopians. So instead of having a small shroud around just around the burner to act as a wind-break, make it taller and run it up the sides of the pot a bit.
 
Here's a picture of a rocket stove that explains what I meant by a shroud (in the pic its called a skirt):

rocket-stove.jpg
 
Yup PC, Plasma TV getting left on for hours, fridges are probably the main culprits but I hate electric cookers so going gas for cooking would be a double benefit so when we freeze in the dark at least we'll have some nice food to chomp on :lol:

Reason for the thread was that I was somewhat taken aback by the amount of kWh in an 8.5 KG bottle. Bunnings currently advertising about $22. Pity there isn't a gas immersion coil system with internal combustion. No doubt there is if you are a major factory or something.

WRT the bill, I'm currently applying a first line of attack type regime: washing machine full loads only, strict lights out when not in use, Don't turn on the hot tap absent mindedly - use dishwasher when full (proven to use less electricity and water than traditional hand washing), TV and Computer stations turned off at wall, shower every second day (honestly here over the winter you don't need to shower every day unless you're an abattoir worker or a rentboy) and fermenting ales at ambient on the garage floor - currently low 20s and dropping in the garage - should save a shitload as well.
 
Hmm rocket stove, nearby National Park for fuel.... :ph34r: :ph34r:
 
Yob said:
Fill up at Supagas which is 5 mins down the road is $25.. they are so frikkin quick it might as well be swap and go, by the time I paid in cash and got back to the bottle he had filled it... I have 2 bottles so never run out, 1 is usually chockas while I run the other one out. 2 easy.
Best way to do it. This way you can squeeze every last bit of gas out of a cylinder without running the risk of being short of gas for a brew.
 
My 9kg gas bottle weighs 18.5 kg when full, 9.5 when empty. I use roughly 2 kg for a 90 minute boil, medium pressure reg, 4 ring burner, 22 L final volume.
 
I do a 60min boil with gas and a spiral burner and 40L batches. Electric HLT. I only got 2 or 3 boils per refill until I got a decent windbreak to put around the burner - now I get 'lots' - not sure how many.
 
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