Using a Peltier kit to cool or warm fermenter

unicamrep · Post by **unicamrep** » Sunday Jan 15, 2006 1:42 pm

Has anyone tried this http://electronickits.com/kit/complete/ ... /ck500.pdf

It can be used to cool when the weathers warm or heat when its cold.

Rubber.Piggy · Post by **Rubber.Piggy** » Sunday Jan 15, 2006 6:15 pm

I haven't tried it, but it seems to be a straight forward solid state heat exchanger. I'd be curious to know how it performs.

It's 12V so it could be run off a lead acid batery, handy for camping/fishing

Dogger Dan · Post by **Dogger Dan** » Sunday Jan 15, 2006 10:17 pm

I have one on my Coleman Cooler, they only drop the temp 15- 18 deg from ambient so if you are sitting at 30 deg your cooler will be around 15

I still llike ice better

Dogger

unicamrep · Post by **unicamrep** » Sunday Jan 15, 2006 10:33 pm

I just thought for fermenting it could be a good thing rather than using a wine fridge.
They cost about 40 bucks.
I might get one and see how it goes.

Dogger Dan · Post by **Dogger Dan** » Sunday Jan 15, 2006 10:37 pm

Yep,

Cheap enough. Give it a go

Dogger

Rubber.Piggy · Post by **Rubber.Piggy** » Monday Jan 16, 2006 6:43 am

unicamrep wrote:I just thought for fermenting it could be a good thing rather than using a wine fridge.
They cost about 40 bucks.
I might get one and see how it goes.

Not a bad idea, you'll have to insulate you fermenter some how. In my case that would bring my 20 deg cupboard down to about 5 deg and I could do lager

Hmmm...

MHD · Post by **MHD** » Monday Jan 16, 2006 1:07 pm

very interesting indeed!

I wonder if Jaycar has a kit similar to this....

MHD · Post by **MHD** » Monday Jan 16, 2006 1:10 pm

Well Jaycar have the module at least
http://www.jaycar.com.au/productView.as ... &SUBCATID=

unicamrep · Post by **unicamrep** » Monday Jan 16, 2006 4:35 pm

This place has a ready to go kit just add 12volts.
http://www.oatleyelectronics.com/peltier.html

It's already attached to container for cooling water.
I reckon you could wrap a sheet of aluminium around the fermenter and a well placed towel could be enough insulation. as long as you weren't trying to keep the fermenter cool in 30deg plus room.

Rubber.Piggy · Post by **Rubber.Piggy** » Monday Jan 16, 2006 5:27 pm

I was thinking to use a stainless steel fermenter stick 2-3 of these on it and then insulate everywhere else.

Alternatively, a couple of stainless sheets sitting in the wort.

I suspect that to cool 19-23L of wort you would need more than one for it to be effective.

U-lsury Hammered · Post by **U-lsury Hammered** » Monday Jan 16, 2006 5:55 pm

There are some larger peltiers on ebay, i think up to 300 odd watts. A couple of things to remember with peltiers is:

a) They can be very inefficient, meaning, you will need some large heatsinks and fan cooling on the "hot" side.

b) Some may require "pulsing" (at a high frequency) power supplies as opposed to straight DC, so it would be better to get a power supply meant for peltiers. They also draw large currents at their ~10-15V.

c) Never operate a peltier without at least a heatsink or "load" on the hot side...it destroys them in seconds (i know this from experience

)

d) You will definitely need more than one (even the larger ones >150 W ) to keep 19 to 23 litres cool and some sort of insulation, and as Dogger said, they only cool a few degrees below ambient especially when trying to cool large volumes at hig temperatures.

Having said all that, it would definitely work and with the right power supply, thermostat and insulation you will have the advantage of being able to heat and cool your wort (as per the oatley ones, however, you would probably need a lot of them) and maintain a narrow temperature range. There is a lot of info on the internet on peltiers, even some Australian guy who has been trying them. I will post his url when i can find it if you want

Cheeno · Post by **Cheeno** » Monday Jan 16, 2006 9:10 pm

I have just finished construction of my all-styrofoam insulation type device (giant esky) and, might I say, it's a wee ripper. Fabrication was a complex and tricky affair that in involved sawing the bottom off one of three styo containers (clean) I got from a mate in the seafood game- that was the complex and tricky part taken care of. You put the sawn frame on top of and underneath the other boxes, glue or tape the bottom two together(without the lids) the fermenter in the middle and hey presto. Add a few frozen bottles and Robert will soon be having a passionate affiar with your one of your parents siblings. Combined with a part time beer fridge (chill it down, keep it cold ) I'm expecting great things. Early observations look good. At $3.70 a styro quite cost effective though perhaps some extra labour. Mind you I'm not really MAKING ice just swapping over bottles.

yardglass · Post by **yardglass** » Monday Jan 16, 2006 9:40 pm

got a pic ?

Rubber.Piggy · Post by **Rubber.Piggy** » Tuesday Jan 17, 2006 9:21 am

looking into it breifly:

farnell, etc have good devices for >$120, not so practical. The cheap ones (jaycar) are apparently capable of maintaining temperature differentials up >=68 deg. However they tend to be low power (<=50W) which means that to use them on 23L of wort you will need quite a few to acheive effective cooling.

For example with one 50W device, the specific heat of water is 4.186J/g degC. So to cool 23L of water by 1 deg would take 32 mins, assuming perfect insulation and optimal performance. So to cool 15 deg would take 8 hours, again assuming perfect insulation and optimal performance. Also remember that wort is not water and is likely to have a specific heat significantly greater than water.

So one device might do, but you would prob want a few to overcome imperfect insulation and changing ambient.

The problem is the high currents needed to power them. The 50W model requires 8A to run optimally. This is approaching the limit of a household mains supply point, and a battery won't last long under these high currents. Don't even think of running two off one power point!! Also to cool a fermenter requires the sort of current to be maintained for days or weeks!!

The low current models are still high current (4A) but also lower power so less effective.

Sorry to get all engineering on everybody, these are just my thoughts. I'm not saying they it won't work, but I am saying that they are probably not the best solution. I'm thinking that a fridge, or even an air conditioner blowing in the general direction of your fermenter would be much more efficient and cheaper in the long run.

These would be good for short term use, ie. cooling your drinks in the esky.

Industrially, peltier devices are used for small scale cooling in places where you can't fit other heat exchangers, they are not very practicaly for med-large scale cooling.

MHD · Post by **MHD** » Tuesday Jan 17, 2006 9:37 am

But at lower power... yes you can only draw 10A off a powerpoint...

The power consumption will be low though (assuming 50% efficiency it would be 100W)

Mind you doing some rough numbers a fridge might be, in the end, more energy efficient...

I guess we have to apply occums razor: Why isnt anyone doing it?

Dogger Dan · Post by **Dogger Dan** » Tuesday Jan 17, 2006 10:54 am

Nice job guys, really nice. Nothing I like better than the numbers

I never thought I would see Occums Razor used on a beer forum, ever

Dogger

unicamrep · Post by **unicamrep** » Tuesday Jan 17, 2006 12:39 pm

As MHD said watts=VoltsxAmps. So 12v x 8A=96watts
So 96watts / 240v =0.4amps, so there won't be a problem running them from 240v. From a power consumption point of view (assuming a perfect AC load), but common sense should be used when it comes to mains supplies and don't hook anything to it unless you know what you are doing.

I've ordered one so I'll let you know if it was a waste of money.
For the effort I think buying a wine fridge from kmart when on special ($199) might be the way to go.

Rubber.Piggy · Post by **Rubber.Piggy** » Tuesday Jan 17, 2006 1:58 pm

unicamrep wrote:As MHD said watts=VoltsxAmps. So 12v x 8A=96watts
So 96watts / 240v =0.4amps, so there won't be a problem running them from 240v.

Be VERY VERY careful here. DC power is V*A, AC is not that simple and mains is AC. Read the devices datasheet before you run it outside the recommended parameters.

Another vital point to consider is that voltage and current are related by impedance NOT power. Ie. Ohm's Law V=IR. In the DC domain this typically means that if you double the applied voltage you double the current, again AC is more complicated.

Cheeno · Post by **Cheeno** » Tuesday Jan 17, 2006 2:22 pm

4 frozen bottles replaced about every 12 hours equals 12-14C, two bottles equals about 16-18C, this was from 26C. Ambient temp. approx 22-29C. Or put ferm. in fridge to desired temp and then transfer (remember to put back tomorrow night's dinner). Remember, trying to get 23L of liquid to do anything is difficult. Yardy can't seem to work the photo part of this doohickey also couldn't contact on your webite. Have a snap if you're interested.[/img]

MHD · Post by **MHD** » Tuesday Jan 17, 2006 2:33 pm

mmm... reactance etc...

Yes, what you want to do is get a power supply capable of delivering 8A at 12V and check it's compliance plate...

8A is bloody huge... it is a large current... (mind you at work we have a powersupply that delivers 14,000A

, but not for Peltiers)

No I am cooling (hehe) on the peltier idea...
Peltiers have been around for a while, there are two things I see as a problem:
1) Why is there no system for doing it already...
2) Good car fridges are compressor/gas driven... only the elcheapo/small ones are peltier...