Peltier Carboy Cooler/Heater

[DeBrewer]

I have had this idea for a while and finally got some time to build a proof of concept. It is a 6.5 gallon carboy, thin copper sheet, peltier element, heat sink, fan, and an exercise mat jacket. I used arctic silver thermal adhesive to bond the copper to the peltier and the peltier to the heat sink. While testing the peltier on the bench it could get to below freezing using that heat sink/fan(I believe it has around a 40 degree temp differential). So I crudely put it together last night to test it and am not very happy with the result. I suspended a temp probe in the empty carboy to monitor temps and over night it only got down to 65 degrees. I think my copper may be too big for my peltier so it's not efficient enough to drop the temp of the copper well enough. Thoughts?

 

[PintoBean]

Check out this write up. It's a little more advanced, but I think there are some concepts there that might help you out. For starters, that large thin sheet of copper is your biggest problem. You need one that is thick, and smaller so that your cooler isn't trying to suck heat out of a spot on the opposite side of the carboy.

http://conical-fermenter.com/wp-content/plugins/download-monitor/download.php?id= 1

 

[dorklord]

Well, a couple of things I can think of right off the bat:

1) The air inside that car, boy is going to be a pretty effective insulator, and with no air movement inside to force mixing, I would think that the air inside might stay warm for quite a while...I know that my mini fridge, when empty, takes an extremely long time to get the air temperature down.

You could try filling the carboy up with water and see if that makes a difference as that water will transfer heat to the glass much faster than air.

As a note, I don't suppose you'd be able get your hands on a small pump, would you?

I've got a pump and water block from a water cooling rig that fried a friend's computer, and I've been thinking about getting a peltier (I've actually got one of those electric coolers, but haven't been willing to destroy it...)

My idea was to stick the water block to the peltier, with the biggest heat sink and fan combo I've got on the other side, then circulate water from a water bath through it. (And then put the carboy in the water bath, of course).

I've been using a water bath to keep my carboy cool for a lager I'm making, and I've found that the water bath keeps it pretty cool, and I can keep it a little cooler if I put some ice cubes in the water, but it is annoying to putting ice in. If a peltier and heatsink could keep the water 10 or 20 degrees below room temperature, that would be pretty nice.

 

[H22W]

Inspired by our little 12v cooler, I was just thinking about experimenting with a peltier ferm chamber. I was thinking more of a foam box to contain a carboy. I am already wondering if a spare window AC might be an easier solution for me as I am sure the AC will have enough cooling power.


I would be very interested if you would fill your carboy with water and report how many degrees cooler than ambient you are able to cool it. Also do you know the watts of your peltier?

 

[user 148322]

thin copper sheet. Thoughts?

Thin sheet, copper or otherwise, won't conduct heat around the whole carboy. But since its done, it won't hurt. Fill with water. You will get the drop given enough insulation. Temp difference is set by peltier device construction and voltage. The question is, how much heat does fermentation generate and can the peltier cooler keep up.

 

[nab911]

These peltier units are what cheaper wine chillers use. They have a small heatsink on the inside (a little bigger than yours and on the outside have a GIANT one, think like 8" x 8" x 3". Even their range is only like 56-70 or so but that might be limited through electronics.

 

[thargrav]

Inspired by our little 12v cooler, I was just thinking about experimenting with a peltier ferm chamber. I was thinking more of a foam box to contain a carboy. I am already wondering if a spare window AC might be an easier solution for me as I am sure the AC will have enough cooling power.


I would be very interested if you would fill your carboy with water and report how many degrees cooler than ambient you are able to cool it. Also do you know the watts of your peltier?

I've moved on to a fermentation fridge since but I used to ferment in a fermentation chamber built from styrofoam sheet. The chamber was 4' long X 2' deep X 2' tall and the whole thing was held together by silver ductwork tape & I could put three fermenters inside. A small window AC stuck through a hole I had cut into the back. You need to jumper across the internal thermostat and controll the AC unit with an outside controller because the AC will not cool low enough on its own.

Here's a link to the type of foam I used.
http://www.lowes.com/pd_222457-1047...Ntt=expanded+polystyrene+insulated&facetInfo=