I made a fermentation chiller...

I posted this in someone elses thread, but deleted and made my own so I wasn't a hijacker...

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.

I had a similar setup before I upgraded my fermenting area, the main difference I put together a pic processor controller that allowed the temperate to be kept at a constant temp. I could set the temp I wanted and walk away the controller monitored the temp and kept it cool.


Now that I have upgraded my fermenting area to a "cellar" I now use the same controller to operate a AC unit and a heater, so now the temp can be kept at the exact temp (hot or cold) that I choose.
It displays the set temp and the actual temp on an LCD (2x18 I think)

One other project that I never did try, was to use the peltiers to cool the wort before transfer to the fermenter, The plan was to use some water cooling to knock the temp down, and then use the peltiers to drop the temp below ground water temp, but never got around to it

Good luck with yours.

Croc4

This looks really interesting. What size Peltier chip did you get (Watts and mm dimensions)? Looks like you got a great price. China or USA? If you had it to do over, would you choose a lesser or greater watt chip?

Thanks!

This looks really interesting. What size Peltier chip did you get (Watts and mm dimensions)? Looks like you got a great price. China or USA?

Thanks!

here is the spec sheet
[url]
http://home.earthlink.net/~eheurlin/eba ... 7-1.14.pdf[/url]

I stated that mine was running at 12V, 8 amps. Its actually only pulling about 6 amps

I guess I'm kinda ignorant, but what is it, and how does it work?

I guess I'm kinda ignorant, but what is it, and how does it work?

Not ignorant. I didn't know anything about thermoelectric coolers until a couple months ago. A lot of small wine fridges run off the same system as well as small camping coolers/beverage coolers that you can plug into the 12V car power.

Peltier chips contain two different alternating types of silicon, P and N. When a current is sent through them, a temperature gradient is created. One side will get very hot, and one side will get very cold. The max difference in temperature of the hot side and cold side of this peltier junction is 79C (174F). The cold side can be below 0F and the hot side can be very hot. The more heat dissapated from the hot side, the colder the cold side will be. There are aluminum fins and with fans on both the hot and cold side. The air inside the cooler is circulated through the cold fins, thus cooling the styrofoam box and beer. I know that doesn't get real specific, but I hope it helps

Noticed you said you used thermal grease...where do you get something like that?

Noticed you said you used thermal grease...where do you get something like that?

You can get it at computer supply stores. The most efficient type contains ground up silver and is a little pricey. I went with a ceramic thermal compound which was fairly cheap.

Noticed you said you used thermal grease...where do you get something like that?

You can get it at computer supply stores. The most efficient type contains ground up silver and is a little pricey. I went with a ceramic thermal compound which was fairly cheap.

Radio Shack has multiple types to fit any budget.

Nice build. I have one of these with nearly an identical design, but mine only gets down to about 45 F. I may have to bolt the sinks together to see if that helps.

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.

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 removed a power supply from a computer that went belly up. Gazillion wires! So I need to power two fans/heatsinks and then the thermoelectric chip as well. Is there enough power available from the computer power supply for all three? I see red, yellow and black wires on the various hookups coming from the power supply.

Also there are four wires coming from each fan: black, red, yellow, green. Not sure which to hook up there. Thanks for any help and comments!

Eventually I'd like to hook this up to a thermostat so it will turn on and off instead of just leaving it on all the time.

Mike

On the power supply the connections that go to the drives, red is 5V, yellow is 12V, blk is gnd. So depending on the fans you have (some are 5v, some are 12v) there should be a label on the center rotor of the fan that tells you the voltage rating.

On the fans they typically have only 3 wires, power, gnd and tac. They are typically coded as red: +V, blk: gnd, yellow: tac

Without seeing the fans I'm not sure what the green would be, try looking up the model # on the net.

Also you will need to "hot wire" the power supply to get it to turn on, normally the mother board does this for you, either cut the wires and solder them together or short the pins on the connector. connect pins 13 and 14 together, this will allow the power supply to power up once the AC is powered.

Just make sure that whatever you do, use good electrical practices(soldering/insulation of exposed wires, etc), its only a small amount of voltage, but its always better to do it right the first time and not have to worry about it.

Stay safe and best of luck,

Croc4

On the power supply the connections that go to the drives, red is 5V, yellow is 12V, blk is gnd. So depending on the fans you have (some are 5v, some are 12v) there should be a label on the center rotor of the fan that tells you the voltage rating.

On the fans they typically have only 3 wires, power, gnd and tac. They are typically coded as red: +V, blk: gnd, yellow: tac

Without seeing the fans I'm not sure what the green would be, try looking up the model # on the net.

Also you will need to "hot wire" the power supply to get it to turn on, normally the mother board does this for you, either cut the wires and solder them together or short the pins on the connector. connect pins 13 and 14 together, this will allow the power supply to power up once the AC is powered.

Just make sure that whatever you do, use good electrical practices(soldering/insulation of exposed wires, etc), its only a small amount of voltage, but its always better to do it right the first time and not have to worry about it.

Stay safe and best of luck,

Croc4

Thanks for the info.

I found this pinout for the 24-pin Molex connector, which is what I have.
http://pinouts.ru/Power/atx_v2_pinout.shtml
It shows that you have to jump pins 15 and 16 to fire up the power. The blacks are grounds or "COM" , the reds 5v and yellows 12v. Oranges are 3.3.

Now for the fan itself with the yellow, black, blue, and green wires I haven't figured out yet how to get the fan motor to turn on. I have tried a few different hook ups but no movement. I have tried another 3-wire fan and it works well off the red and black wires. Not sure what the white wire does. The three-wire fan is not the one I want to use, but perhaps I'll have to compromise if I can't figure out the other fan's four-wires. This four-wire fan is a AVC (DA0208xxxx) 775 set up for Intel. Couldn't find pinouts for it. It is ideal the way it is mounted and can be easily matched to another one for a perfect set up - if I can get it running.

Thanks!

That's pretty awesome! I might try this, too. I've been debating on whether to get a chest freezer or a mini fridge or something to get better temperature control, but this might be a lot cheaper. Especially since I won't be tempted to keep beer cold in it while I'm not fermenting.

Cheers!
Rich

Mike,

Here is the pin out for the 4 wire fan
http://www.pavouk.org/hw/fan/en_fan4wire.html

The white wire on your 3-wire fan is the tach line, and the green wire on the 4-wire fans, is used to measure rpms of the fan, it will pulse once per fan revolution. And you only need this if you plan on using some micro controller to monitor and or change the fan speed.

According to the link no PWM signal should cause the fan to run at full speed, take a volt meter and measure from gnd to the blue wire, you should get either 3 or 5v, if you don't, get a 1 to 4K resistor and pull the blue line to 3.3v. If this does not work, you could try pulling it to 5v. If that still does not work then either the fan or power supply is bad. Measure the voltage input to the fan, should be 12V according to the link.

On the power supply, make sure you have the right # of pins, 20 or 24. This will change the pins needed to be shorted, I posted the 20pin version, your link is for 24 pins. Just make sure you use the right one.

Croc4

Anybody still working on this kind of cooler? Updates?

I have been experimenting with a small styrofoam cooler to get the system operating, using a Johnson Controls digital temperature control.

With the system on for an hour (no temp control), the temp got down to 44 degrees F. I am using the power supply from a computer for both fans (5v) and the thermochip (12v). By the way, what a cool little power supply to have around for various tinkernut projects. I am wondering if the low amperage supply of the computer power supply won't allow the cooler to get below 44 F. If that is the case, anybody know of a good power supply that would provide more amps?

Comments appreciated.

Side Note: In the photo you can see that two homebrew suppliers sent me little "sursies" with my orders that are appreciated.