Peltier controlled fermentationy device

[chris2012]

I'm building a peltier controlled fermentation chamber.

I'm going to use this little beauty which I ordered from China, to heat/cool water, which I pump through an
SS coil in the beer.

It consists of 4 peltiers, roughly 200W in total.





I'll make use of h-bridges to 'flip' the peltiers to either heat or cool:

[setmash]

This is very interesting - do you have a link to where you bought the device ? How do you intend to change from cooling to heating ?...what are H bridges ?

Cheers

[chris2012]

Theres a fairly nice example of a h-bridge with switches on http://en.wikipedia.org/wiki/H_bridge

But essentially they allow you to flip the polarity, going to the peltiers, which will allow me to change from cooling to heating.

I got it from here - http://www.aliexpress.com/store/product ... 23364.html

[setmash]

Many thanks that's very interesting. Have you tried cooling and heating with it yet ? What size batches do you brew in ? Are you building an insulated cupboard or using a jacket ?

[chris2012]

Not yet, will hopefully give it a shot tomorrow, i'm thinking of heating ~5 gal of water to like 30C and cooling it down from there with the peltiers, to see how low it'll go.

I brew 5 gal batches at the moment, but am potentially gonna increase my batch size soon.

I haven't thought too much about insulation yet, possibly I may look at getting some of that metallic bubble wrap to wrap around the bucket.

[boingy]

Make sure you add plenty of heatsinking....

[setmash]

It will be really interesting to know if it can cool (down to what temp) and heat using the same device. I assume your pumping the coolant from the radiators through a stainless steel coil in the wort ?

[chris2012]

Yup, I'll just be pumping water through the SS coil, which will be suspended in the wort

Edit: the heat sinks are attached to the water blocks boingy - just added another image so you can see them

[setmash]

It's a cracking little device and at $68 it could be well worth it. Looking forward to hearing about the tests

[far9410]

How does it work ?

[BenB]

I hope it works out for you. I looked at doing something similar but the inefficiencies or peltiers seemed to be a stumbling block. As was keeping the right differential between the hot and cold sides. Good luck though and keep us updated!

[setmash]

Looks like this generates approx 150W of cooling or heating power. Best case that means it will take it 18 minutes to heat or cool 40 liters of wort by 1 degree. So to crash cool my 40 Liter batches from 23 degrees to 1 degree will take it 6.5 hour (assuming no other system losses) to get the wort down to that temp. Not sure a fridge would be much quicker though ....

[chris2012]

So I just built a heath-robinson style testbed, unfortunately it looks like PC PSUs (or at least mine) aren't rated for 20A on a single rail

As the cable on the PSU was getting hot.

I did however see ice forming on the heatsinks, indicating it was heating the water and cooling the heatsink. (With red wires from the peltiers connected to positive 12V)

I'll probably buy something like - http://www.ebay.co.uk/itm/251690603895? ... EBIDX%3AIT

[setmash]

No expert but you would of thought with it being sold as a chiller it would cool the radiators with the red positive wire on +12v. Did you measure the water temp in the coil, did the coil get warm or cold ? Thanks

[chris2012]

It's actually sold as a sort of air conditioning type device I believe, to blow cold air, so it makes sense that the heat sink fins were getting cold.

I didn't measure the temp alas, as I didn't have it on too long, I'll give it another shot soon when I've got a new PSU, but I'll play with getting the
H-bridges to work in the meantime.