I thought I would post some pics of the fermentation chiller I made. I have to tell you now that its not glamorous at all, but its effective. It uses thermoelectric cooling, aka peltier chip. I tested it the other night with 70F water. I know I will have to fight against the heat put off by fermentation as well, but I just wanted to see what its cooling power was. It cooled 5 gallons of 70F water down to 46F in 24 hours. I had to turn it off at 24 hours because I was going out of town and didn't want to leave it running. With nothing in it, I can get the cooler down to 38F, so it may have dropped the water temperature lower had I left it running. My 6.5 gallon carboy fits in the cooler, but I had to cut a hole in the top for an airlock to pop out of. I can effectively seal around this hole with a towel.
I don't have room for an extra freezer or fridge...hence, this little project.
Here is the cooling unit. I made two units like this and used one in the cooler pictured later.
The heatsink is on top, the coldsink is on the bottom.
Note: there is a fan mounted on the coldsink, but is not pictured.
You can see the peltier chip sandwiched between the hot and cold sink. I used thermal grease where the peltier chip contacts the sinks. The sinks are bolted together to provide pressure for effective heat/cold transfer.
This is the other unit and the one I used. I cut some polycarbonate and mounted the unit on the polycarbonate and sealed with silicone
Here is the whole unit mounted on my styrofoam cooler. It is powered by a power supply unit from a computer. I don't have an extra laying around right now, so I had to unplug stuff from my PC in order to test it.
A closer look. It circulates the air in the cooler against the coldsink utilizing the fan mounted on it.
Do you like how I have put the case of bud light to good use---to raise up my pc so my wires would reach...
I know it doesn't look great, but it works. I have two of these large styrofoam coolers. I used this one to get an idea of how I might mount everything on the cooler. I may use the other to make a more finished looking fermentation chiller enclosed in a wood case.
I have the peltier chip running on the 12V rail of my PC power supply. It draws about 8 amps I think, so its not a very efficient system from an energy standpoint. I will soon have a temperature controller that will turn on and off the entire power supply so I can set a temp and only have the power on when I need it. I also need a spare power supply unit if anyone has one they want to get rid of....
Oh yeah, almost forgot to mention the cost...
Peltier chips-$3 ea on ebay (got four of them)
Heatsinks and fans- $1.50 ea on ebay
Polycarbonate sheet-$4 at HD
Power supply-$0 a friend of mine may have an extra for me
Temperature control- I anticipate spending less than $30-a friend might help me make one too..
Styrofoam box- $0
So, not including the extra parts I have laying around (I bought heatsinks in a lot of 10 and four pelt chips) I have about $10 in this chiller so far, up to 40 when I'm finished.
I will try to answer questions if you have any. I welcome any comments or suggestions too.