Effective BTU - You might be surprised.

Effective BTU is just a way to describe how much heat your burner is able to put into the liquid you're trying to heat. It is NOT the rated BTU of your burner itself. You can also express effective BTU as heating efficiency or how much of the heat produced actually gets into the liquid.

The 23 tip ring burners are rated at about 100,000 btu on natural gas. That works out to about 4400btu per tip. I'm only running 13 tips on my HLT burner so it's theoretically capable of about 57,000 btu.

I measured the actual heat transfer today into 8 gallons of water. 12,100 btu.
It takes a little over 6 minutes on average to raise 8 gallons of water 18f. It's not linear though. The hotter temp you start from, the longer it takes for the same rise, assuming that the cold ambient temps are affecting it.

Another way of thinking about this is that it's the equivalent of running a 3500 watt electrical element.

Just for reference, 1 BTU will raise 1 lb of water 1* F.

Right on. I just used BTP's calibration tool so I don't have to think or calculate anything.

Wow, I spitballed about 40% efficiency for my burner but never confirmed... your numbers are just over 20%, all electric, here I come!

I always liked the idea of using 11KW of heating power to come up to temps fast rather than waiting around on brew day when I want to brew then maintain temps with one 5.5KW element. The only propane used is for the BBQ the past 6 years.
Hot days brewing around propane heating sucks i'm hot enough, propane
causes too much bier drinking and screwing up the brewing process.

So now i've now read on this form over time that propane was once 60%, to 40% and now down to 21% efficiency of heat energy to the brewing. Add to this Blue Rino propane bottle exchanges of 3 1/2 gallons not 5 gallons as in the past with $23.95 exchange rate. At $6.84 a gallon this makes even gasoline look cheap in my area. Insulation is your best friend with electric heating.

WOW Bobby, that blows.

I know some other guys have done this sort of testing and found that on thier burners/stands that they were close to 40% in thier testing regime... still not spectacular.

The most I can run on my new build is 9000W in the kettle and RIMS... but that is over 30K BTUs (minus heat loss etc etc) (granted this is on a 5-10 gal system) That is a lot of gas to get 12K into the kettle...

Were you using a covered pot?

KiltedCorpse said:

Just for reference, 1 BTU will raise 1 lb of water 1* F.

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I read a reply on this forum not that long ago that it raised one gallon of water with 1 BTU, with this posted formula I can heat my house and take showers all winter for under $50.

One gallon, one pound... meh, close enough

The Pol said:

One gallon, one pound... meh, close enough

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LOL no doubt. Don't we wish it was a gallon and not a pound. Damn physics anyway.

KiltedCorpse said:

LOL no doubt. Don't we wish it was a gallon and not a pound. Damn physics anyway.

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I dunno, my January heating bill this year is $100 lower than it was last year... so maybe things are changing, maybe it is global warming?

My old 55K burner was slow to heat and slow to boil... heck it was probably only 11K BTU into the kettle! 44K BTU just heating the outdoors.

I'm trying not to latch on to the burner efficiency numbers because all of that hinges on knowing how much heat the burner is spitting. Just because the mfr rates the burner at 100kBTU doesn't mean it actually is capable of it. Error there. Even if it were capable of XXbtu, given the variable pressure and flow of a home NG system, especially mine, that 100k burner might only be capable of 70K. So, maybe I'm running 20%, 40% whatever. I might also have the kettle an inch below or above the optimal distance from the burner. With all those potential variables, the only thing I'm sure of is how fast this current configuration will heat water.

To put it into brew day perspective, heating 8 gallons stike for a 10 gallon batch of pils will take me 40 minutes. Yes, I'd love for that to be a little shorter, but that's also when I'm installing my false bottom, milling grain and making coffee. Another trick I've used to hurry up is to heat 2-3 gallons of the strike directly in the MLT. The effective BTU there is 5800BTU and it not only speeds the strike heating, but completely takes the heat capacity of the vessel itself out of the stike temp calculation, reducing the strike temp from 173 to 163 (typical).

The Pol said:

Were you using a covered pot?

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In the HLT test no, in the MLT yes. I think that was a flaw right there because I did observe a non-linear time to heat depending on the starting point. The hotter the water, the longer it took for a 18F rise, no doubt due to increased heatloss to the cold ambient.

I'd repeat the HLT test when I'm actually brewing to see if the lid helps at all.

The old multi-tip burner on my previous HLT setup looked like it was melting the house in this picture of a test run. Let it rip too hard and the keggle skirt would glow bright orange.


I went all-electric and haven't looked back.