DIY Peltier "ICA" Chiller

[revance]

So after trying to buy a waterblock from nano-customs I gave up and decided to make my own. They stopped selling them right after I ordered one and haven't started offering them for the 24g again. I don't really trust their 12g one either because it appears to be coated copper that comes into contact with the water.

 

Anyway, I decided to make one myself. This design uses an acrylic block that has a water chamber, an input, and 2 outputs cut out of it. I did it this way because of space constraints. So far only the water chamber and outputs are cut out. I still need to create the input (a 1/2" barb on the bottom) but I don't have the correct tools for that size yet.

 

The water will come directly into contact with the ceramic plate of the peltier module. I am using a low profile copper heatsink (no worries, it won't come near any water) and the stock fan. I was happy that I had enough room for the stock fan because I didn't want to use a thinner fan because it would be louder.

 

So here are the parts:

 

 

 

Here is it put together (except the 1/2" barbed input):

 

 

 

I will post updates once I get the input threaded on and do a test run.

[ccjung]

Looks good!

 

The ICAs actually make direct contact with the peltier as well. We are running an injection molded waterblock and there is no direct contact with the copper heatsink, which is usually mounted in the hood.

 

I like the use of 2 outlets and the contact area. My main concern would be that the heatsink may be undersized for the amount of Q + the overhead added by the TEC.

 

Overall, I like it. Glad you were able to figure something out and sorry we werent able to get you the waterblock you were looking for.

 

The new plastic/direct contact ICA concepts are a great leap forward, and in my observations and tests, make great sense.

 

Now I am cooking up a temp controller that will allow you to do 2 way heating/cooling.

 

Thumbs up on the DIY!

 

Chris

[revance]

I'm glad to hear that the water doesn't come in contact with the copper on yours. From the pictures it looked like it did.

 

The heatsink will actually move more heat than the cheap full sized ones because it is solid copper. The heatsink is rated for use on a P4 processor, which gets much hotter than the peltier is going to get.

 

No worries on the waterblock I ordered... I understand. I just needed something right away and didn't have time to wait. I appreciate all the help you gave me.

 

Anyway, hopefully this works out.

Edited June 6, 2006 by revance

[shookbrad]

nice! Where did you get your peltier? Are you just going to use 12V dc or are you going to put some kind of regulator on it for temp.

[revance]

I am working on a controller that will change the voltage depending on tank temperature (kind of like the iceprobe controller). Until then I will just use a 12v 4.5A power supply I have laying around.

 

I honestly don't remember where I got the peltier, I also had that laying around. The only thing I had to buy specifically for this was the heatsink, and even that I could have used an old one but wanted it to be low profile and copper.

[oogie]

wow, so acrylic block actually does work? Wouldn't it be much less effective then metal blocks?

[tinyreef]

i would think a glass or porcelain block would exchange better. any custom ceramic people around?

 

i would think the acrylic would insulate it too much but i guess it's probably the easiest material to work with. did you hog it out as thin as you'd dare toward the exchange side?

[revance]

There is no acrylic between the peltier and the water, there is just the ceramic plate of the peltier. So the water is only insulated from the outside air, which is probably good since it is right next to the lights.

[tinyreef]

ah, i'm sorry i didn't read that last paragraph. (it was late)

 

so the acrylic is just to provide a larger enclosed circulatory area for contact?

 

i'd been wondering about a stainless container or epoxy-coated metal container as a heat exchanger. my diy chiller only uses plastic tubing and it sucks @ss. it drops the temp about 4~6F but i think it would be much better (or as effective on a larger system) if the heat exchange was optimized.

 

does anyone know how well does marine paint/epoxy really holds up? i wouldn't coat copper but i wouldn't be so worried about steel or stainless.

[revance]

At first I was going to make a titanium "heatsink" for increased contact area (it was going to be a plate with lots of little tabs cut out and folded up) but my buddy with a laser mill found that his mill was incapable of cutting titanium. I imagine I could have a real company make it for me, but the idea is to be cheap.

 

I don't need much chilling, so I'm sure this will work fine. The best part is it only cost me about $15 because I already had almost everything.

[supernip]

titanium for the heatsink or to replace the peltier? Ti is really expensive in bar form just for the raw material, gonna be expensive

[revance]

No, the Ti was just going to be a thin sheet to sit on top of the peltier and it would have some tabs cut out of it and bent up to make "fins" that stuck up into the inside of the waterblock. To sort of create a heatsink inside the waterblock on the contact side of the peltier. Its only purpose would be to increase contact area. Since I can't have it laser cut for free, I'm not going to mess with it.

[revance]

Well, I finally got around to testing this out. I hooked it up to a bucket with about 2.5g of water in it to try it out. The ambient room temperature was 79F. With a small 9v 1.5A power supply hooked up it kept the water at about 72F. I then hooked up a 12v 2.5A power supply and WOW does that thing get COLD!!! I ran it without the pump hooked up and the little bit of water that was left in the waterblock immediately froze when I turned it on.

 

I let the big power supply run overnight and when I woke up the water temp was 65F, the ambient temp was 79 when I turned it on and 75 in the morning. Next step is to just install it and see what happens.

[el hombre loco]

I had tried a similiar experiment uses the new water block form Nano-Customs that allows all 40mm X 40 mm surface area of the water to contact the Peltier. I used a 15 volt, 4 amp power supply and tested in about 1.5 gallon bucket and was able to drop the water temp down abut 2 degrees in an hour. Ambient was 75 degrees.

 

Since my Nano cube is 24 Gallon and I need about a 4 degree drop when scaled up the system would not be able to cool my tank quicker then the heat rises in the day ( I get about a 6 dgree increase on a normal summer day). I am using evaporative cooling (80 mm fan) right now which will keep my temp at 78 degrees opn a normal day.

 

My concern is come August when my room temp climbs from the mid 70s to the low 80s this won't be enough. Based upon my exeriments the Peltier won't do it either.

 

I would be very eager to see the results of your testing in a real size tank or I'll be likely be buying one of the new R13a based chillers which I know have the BTU to cool. I'm trying to avoid the noise and the cost as the Aquarium is right next to my bed. Plus it's more fun to build one ourselves.

 

Jim

[The Propagator]

Very good work!

Edited June 24, 2006 by The Propagator

[doncb]

I had tried a similiar experiment uses the new water block form Nano-Customs that allows all 40mm X 40 mm surface area of the water to contact the Peltier. I used a 15 volt, 4 amp power supply and tested in about 1.5 gallon bucket and was able to drop the water temp down abut 2 degrees in an hour. Ambient was 75 degrees.

 

Since my Nano cube is 24 Gallon and I need about a 4 degree drop when scaled up the system would not be able to cool my tank quicker then the heat rises in the day ( I get about a 6 dgree increase on a normal summer day). I am using evaporative cooling (80 mm fan) right now which will keep my temp at 78 degrees opn a normal day.

 

My concern is come August when my room temp climbs from the mid 70s to the low 80s this won't be enough. Based upon my exeriments the Peltier won't do it either.

 

I would be very eager to see the results of your testing in a real size tank or I'll be likely be buying one of the new R13a based chillers which I know have the BTU to cool. I'm trying to avoid the noise and the cost as the Aquarium is right next to my bed. Plus it's more fun to build one ourselves.

 

Jim

When I got my v1.0 ICA the temps in my 24g Cube were running 86f. The ICA was able to get the temp down to 80f and keep it there. And that is with a room temp of 78f. Once the body of water is cooled down and the ICA is constantly adding cooled water it is much harder for the water to do that 6f increase.

[The Propagator]

Put a fan on the back blowing acrossed the water surface and you will get even more of a temp drop. ( probably 4-5 more degrees.)

 

On my 100g prop tank I only use one 6 inch clip on fan blowing over the length of the tank.

That alone drops my temp by 6 degrees. ( and I have 2 x 96w pc's and 2 x 250w HQI in a closed fixture hanging 4 inches above the water. 7 pumps putting heat in the tank , 2 301 aqua clears, 2 mj12's, 1 mag 7 , one 1400 gph no name.

I have an open top sump so I get alot of evaporation cooling/

Works out realy well.

One day this summer it got to 86 ambient temp degrees in my basement and the tank stayed at 80 deg. with just that little fan and my open sump ( two small fans in the lighting fixture as well, pusher and puller).

Strong believer in fans here.

Just use an auto top off or your in for WICKED SG swings and burned up pumps.

[revance]

Yeah, the only way you can beat a fan blowing over the surface is a full sized chiller. However I don't want the evaporation and I don't want to have the hood open with a big ugly fan on it anymore. The whole purpose of a NC is to have a nice neat package.

[Reefunk]

how many gallons it would be supported?

Edited July 5, 2006 by Reefunk

[Perpetual98]

pardon me for asking what may have been posted, but how do you attach the peltiers to the block? I've got 3 40mm peltiers that I picked up off of ebay for a song and I'd like to use them for my 2.5G that has major temperature swings. I was just going to glue them right to the tank glass and see if they had enough 'oomph' to chill the tank a couple degrees right through the glass, but your idea seems much more fun.

[revance]

I just have a rubber gasket between the block and the peltier and the whole thing is sandwiched together with screws (that hold the whole thing into the NC hood).

[Perpetual98]

Ahhh, I see said the blind man!

 

So I could probably do something similar (I don't have a NC) and drill/tap a set of holes into the block and attach the peltier/heatsink using those holes.

[Perpetual98]

Another dumb question. In theory, isn't the "cold" side on the peltier propotionally as cold as the "hot" side is hot? I understand that the heatsink is there to protect the peltier, but what is the fan for? The same thing? Wouldn't you want the "hot" side to get as hot as safely possible or does it not make that much difference? I would think that the fan would cool down the "hot" side and make it not as efficient. Perhaps it's just moot and I'm a moron.

[revance]

You want to keep the hot side as cool as possible.

 

In an attempt to explain as simply as possible...

 

The peltier effect creates a temperature difference from an electric voltage. So for a given voltage, you will have a specific temperature difference created. The cooler you can keep the hot side, the colder the cold side will be.

 

You are essentially moving heat from one side to another (plus adding some from the current through the semiconductors). As heat is transfered, the hot side will heat up and will stunt the cooling on the cold side. So the faster you can get the heat off the hot side, the better the cooling will be.

[Perpetual98]

That makes sense now. I was under the impression that if the "hot" side was a bazillion degrees, the "cold" side would be negative a bazillion degrees.

 

It makes sense that you would have to evacuate heat from the hot side. In a nutshell, you want the "hot" side to do as much work as possible and the heatsink/fan will make the "hot" side try to keep up with their cooling capacity.