Anyone ever hear of using Peltier effect as a wort chiller?
- Thread starter megaman
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
techrunner
Well-Known Member
i have done a little research at pertiers, but its limited. i am no expert. i am however an engineer, so for what its worth, here's my opinion. peltiers are able to move relatively small quantities of heat. for cooling wort, you would be taking heat from a hot body, the wort, and moving it to a cooler body, the atmosphere. The peltier will (i think) actually be running in reverse, trying to generate a voltage from the heat difference in this case. if you put a light bulb (very small one) on the leads in this configuration, the peltier will actually generate electricity using the heat of the wort, as it is cooling.
in short, its not gonna cool wort much faster than just atmospheric cooling. if you want to save water, i think you'll be better off with no-chill.
in short, its not gonna cool wort much faster than just atmospheric cooling. if you want to save water, i think you'll be better off with no-chill.
I dont mean using it to generate electricity-I mean using electricity to drive the heat generation (input watt power) in the atmosphere side and having the wort side cool - ideally using the metal kettle as the cold side - but maybe it would have to be some other metal type.
Not really into saving water - I was just reading about fridges because Im in the middle of taking mine apart and rebuilding it with a netdunio controller - and came across how camper fridges work and that they use the peltier effect.
since homebrew is pretty much open to any solutions I figured someone somewhere may have tried this effect before.
Not really into saving water - I was just reading about fridges because Im in the middle of taking mine apart and rebuilding it with a netdunio controller - and came across how camper fridges work and that they use the peltier effect.
since homebrew is pretty much open to any solutions I figured someone somewhere may have tried this effect before.
techrunner
Well-Known Member
yes, but if you put power to it, it will move heat from the cooler side to the hotter side, which is opposite of what you want to do.
Golddiggie
Well-Known Member
You would need something very cold on the other side, I would imagine, to get the wort to cool down to pitching temps. At that point, you'll have a rather cumbersome assembly to try and chill your wort. It probably wouldn't do it all that fast either, unless you were using something super-cold. You might have better luck just making some refrigeration coils to place on the sides of the kettle for when it's time to chill the wort. Leave them off during the boil, and then secure them once you're ready to chill. Of course, you'll need a compressor and such to push the coolant through the lines, so it's not going to be a small assembly. No idea how long it will take to cool down the entire batch either. I'd not put the coils into the wort, since you could develop a leak, which would be rather bad inside the wort.
If you wanted to super-cool some glycol for a CFC chiller, that might work. Although it could be another case of not really being more effective than the normal chiller.
Unless your ground water supply isn't very cool during the summer, I see these as limited use items. Also more of something you wouldn't want to move around much. But if you have a brew stand where you could secure most of it and only shift part of it, it might work...
If you wanted to super-cool some glycol for a CFC chiller, that might work. Although it could be another case of not really being more effective than the normal chiller.
Unless your ground water supply isn't very cool during the summer, I see these as limited use items. Also more of something you wouldn't want to move around much. But if you have a brew stand where you could secure most of it and only shift part of it, it might work...
bblack7489
Well-Known Member
I've though this through for various applications. The one that I got the furthest on was using a peltier-based cooler in a tap so that I could cool beer without using a kegerator. The back of the napkin calculations for the kegerator idea put into perspective exactly how much power we were talking about, and that was for a 72F to 40F temperature drop. For 210F to 70F, you're talking about way more power.
Briefly, 1J is the energy required to raise the temp of 1g (1cc) of water 1 degree C. For a 5 gallon batch going from 210 to 70F, that works out to roughly 20kJ per degree C or 820kJ total. Assume you purchase a 200W peltier that operates at 20% efficiency (both of which would be a stretch and would assume ideal conditions), then it will take you roughly 5 hours to cool your 5 gallon batch.
I think that my handwaiving math is pretty close on that one.
Briefly, 1J is the energy required to raise the temp of 1g (1cc) of water 1 degree C. For a 5 gallon batch going from 210 to 70F, that works out to roughly 20kJ per degree C or 820kJ total. Assume you purchase a 200W peltier that operates at 20% efficiency (both of which would be a stretch and would assume ideal conditions), then it will take you roughly 5 hours to cool your 5 gallon batch.
I think that my handwaiving math is pretty close on that one.
Golddiggie
Well-Known Member
bblack7489... Wow... Tons of power and a long time to chill... Probably get faster chilling with a cold water bath...
While it might be more 'green' in concept, I think active cooling will do a better job and be more 'green' in practice.
I would be interested in knowing how long it would take the cooling parts from a ~5000 BTU window AC unit to cool down a 5 gallon batch of wort. Having the coils connected to the sides of the pot, not into the wort. Or would it be better to immerse the coils into water, and run the feed line for an IC through that same water? More of a thought than a design idea, since it probably won't be cost effective to run the AC unit to only gain a small increase in cooling efficiency. At least where I am. If your ground water is over 70F most of the year, then it might make more sense.
While it might be more 'green' in concept, I think active cooling will do a better job and be more 'green' in practice.
I would be interested in knowing how long it would take the cooling parts from a ~5000 BTU window AC unit to cool down a 5 gallon batch of wort. Having the coils connected to the sides of the pot, not into the wort. Or would it be better to immerse the coils into water, and run the feed line for an IC through that same water? More of a thought than a design idea, since it probably won't be cost effective to run the AC unit to only gain a small increase in cooling efficiency. At least where I am. If your ground water is over 70F most of the year, then it might make more sense.
camiller
Well-Known Member
Or the peltier is backwards.
IIRC someone was trying to use one to maintain fermentation temps and it couldn't keep up with that. You need a really good peltier (or multiple of them) for it to work just to maintain fermentation temps, it would be a really slow way to cool wort, unless you want to spend hundreds to completely cover your kettle in them.
I think Morebeer sells a conical with two of them mounted with heatsinks and fans.
Basically I don't think it is likely to be practical for chilling wort.
Golddiggie
Well-Known Member
Let us know when you have your fusion reactor up and running to power the chiller...
We'll want pictures of course... Or how many wind turbines will you be installing in order to provide the power needed to run the kettle covered in them? 
Either way, we'll want pictures... 
You are actually referring to the calorie, not Joule.
It takes about 4.18 J to raise 1g of water 1°C.
Water has one of the highest specific heats of all common substances. For example iron is 0.45 J/g/K, lead is 0.13 J/g/K. This makes it hard and expensive to heat water.
Peltier elements are sometimes used to cool CPUs and laser diodes. They can be used to heat or to cool depending how they are connected. They are expensive though, and for large cooling job other systems are probably better.
My dad had a peltier fridge at the cabin many years ago. It was almost perfectly quiet since it had no compressor. You could hear some liquid quietly moving inside, but that was it. I think the drawback of these fridges is that they are not very efficient. Edit: It was probably an absorption fridge rather than peltier.
bblack7489
Well-Known Member
Damn, you're right. I missed a unit conversion in there. That's what I get for doing too many things at once.
Regardless, the energy required is pretty insane to cool 5 gallons of wort. That was more the point than the actual numbers.
I like the idea of using it to control fermentation temperatures, that's worth thinking about.
Regardless, the energy required is pretty insane to cool 5 gallons of wort. That was more the point than the actual numbers.
I like the idea of using it to control fermentation temperatures, that's worth thinking about.
Similar threads
