Well this is my first summer with an aquarium and I am starting to get worried as I live in a dorm/apartment with no airconditioning. My room is already getting up to 82-83 and my tank is hitting 85-86 so I decided I should investigate chiller options. I saw a thermoelectric cooler designed specifically for the nanocube http://www.nanotuners.com/index.php?cPath=34 but it runs $90 and requires cutting into my nanocube. I decided I could engineer a cooler from scratch that fits my needs. So here is my experiment.
First things first, I purchased a 320 Watt Peltier cooler off of ebay for $13. It can run at 24 amps at 15.6 volts and pull 243.5 watts of heat. I already have a 13 amp 12-15 volt power supply laying around, if that doesn't do the trick then I can probably find one on ebay if I look hard enough for $20-30 which will (I think I got the 13 amp supply for around $20 shipped). The nanotuners ($90) TEC cooler has an 8.4 V 2.5 power supply (or a 12 V 4.5 amp for an additional $32.95) and the ICE PRobe (over $103) has a 12 V 4-5 amp power supply. So I should beat the heck out of both of them.
Heat Exchanger. Here is what has been really driving me crazy trying to figure out how I am going to accomplish this. The main concern is corrosion (I am building this for FW but with intention to use or sell for SW). Pretty much the only metal you could directly use is titanium and not have to worry about corrosion. I noticed the nanotuners TEC heatexchanger was a dinky Delrin piece. I was contemplating all these solutions that I could fabricate myself such as taking thin walled silicone (or other plastic) tubing and pot it in some thermally conductive substance (glue or something) that could make the thermal contacts. Or I could mill a channel in something like ABS, Acrylic (something non thermally conductive nor corrosive) and then bolt a piece of metal on top to seal it. I could drill and tap holes to put pipe fittings in. I could simply coat the side of the metal that will contact the water with some film (either spray on paint/epoxy or just lay down a very thin piece of something like polyamide) to prevent corrosion. Although the film will probably have a low thermal conductivity, it will be so thin it will not affect the heat transfer that much. But then I decided it would also be cool if I could devise a setup that most people could use regardless of whether they had access to a machine shop or special tools. So then I found out that there are heat exchangers made for liquid cooling CPU's that are almost exactly what I wanted to build. Here are a few of interest
http://www.coolermaster.com/index.php?L ... L-D3A-CNU1. This is the one I think I am going to use, it has 1/4 tube fittings and the copper plate is removable so I can just take it off and spray or coat the one side that will contact the water to prevent corrosion.
Another one that is smaller and designed to fit a CPU
http://www.directron.com/clw0038.html
http://www.directron.com/chc35d06.html This one was interesting because it is gold plated and rather cheap. Although I found out that gold will corrode in salt water (although very slowly). I could also coat the inside but it seems like it will be more difficult.
There were a few other CPU/HD/GC heat exchangers that looked promising.
So now I have the heat exchanger, I either thermal tape the heat exchanger to the Peltier element or clamp it somehow, but now I need a fan.
Fan: I ordered a really crappy one (I am having regrets now) for $5 shipped. I think I will need a better one.
I have a few things in mind depending on exactly what I get such as building a new metal plate that can screw into both the heat exchanger and the fan. Let me know what you guys think. I think if this works out it could easily be scalable to larger systems (more gallon tanks). There is a next higher size Peltier element on ebay for about $19. The harddrive heat exchangers can easily accommodate two of these larger elements in parallel which if you had the proper power supply could be pulling a total of 60 amps at 15.4 volts. Each of the larger TEC can transfer 270.5W so thats a total of 541W theoretical. Of course you could expect maybe 1/2 that by the time it finally reaches your tank but thats still a good amount of cooling. That is about the amount of heat drawn (and thus dissipated into heat) by most larger tank's light and pumping systems.
DIY Thermoelectric Nano chiller for my 24-gal Nanocube
-
helicopter
- Puffer Fry
- Posts: 32
- Joined: Wed Feb 21, 2007 5:32 pm
-
helicopter
- Puffer Fry
- Posts: 32
- Joined: Wed Feb 21, 2007 5:32 pm
Pictures. If you can't see the pictures you can go directly to my post at http://www.nano-reef.com
http://www.nano-reef.com/forums/index.p ... 0141&st=20
This is the heat exchanger. It was machined from 1 inch acrylic. All the edges were beveled on a belt sander and then finely sanded/polished. The pictures really do not do it justice, it actually looks really nice in real life. One side of the piece was milled out (a channel for water to flow through) and then capped with the titanium plate (screwed in with 10-32 screens and sealed with RTV). I have not hooked everything up but she appears to be "sea worthy" in that I can create suction with my mouth on one hose barb while plugging the other hose barb and it was hold the suction for a long time as if I were sucking directly into a glass bottle.
In this view you can see that 6 counter sunk through holes for the 1/4 20 machine screws which bolt onto the heatsink to sandwich the Peltiers.
Two views of the Titanium back plate. One side of the plate is sealed inside the cavity and exchanges heat with the water. The other side of the plate will contact the Peltier coolers (with Artic Silver 5 for good contact). The image makes it appear as if it is rough but it is actually sanded very smooth.
Large black anodized aluminum heatsink with two thermally controlled computer fans on the back (Thermaltake 92 mm Smart Fans).
The Peltier elements contact the reverse side of the heatsink. In this image you can see the tapped 1/4 20 holes for mounting the heat exchanger as well as milled out countersinking to provide clearance for the heads of the screws holding the titanium plate to the acrylic.
Fits like a glove on top.
125 amp 12 V power supply I got on ebay for a ridiculously good deal ($80). It is used to power both Peltiers which at 12 at their peak (when you initially turn them on and they are still cool they draw the most current) they will draw around 40 amps total. After heating up their hot sides they each settle down to about 12 amps each.
http://www.nano-reef.com/forums/index.p ... 0141&st=20
This is the heat exchanger. It was machined from 1 inch acrylic. All the edges were beveled on a belt sander and then finely sanded/polished. The pictures really do not do it justice, it actually looks really nice in real life. One side of the piece was milled out (a channel for water to flow through) and then capped with the titanium plate (screwed in with 10-32 screens and sealed with RTV). I have not hooked everything up but she appears to be "sea worthy" in that I can create suction with my mouth on one hose barb while plugging the other hose barb and it was hold the suction for a long time as if I were sucking directly into a glass bottle.
In this view you can see that 6 counter sunk through holes for the 1/4 20 machine screws which bolt onto the heatsink to sandwich the Peltiers.
Two views of the Titanium back plate. One side of the plate is sealed inside the cavity and exchanges heat with the water. The other side of the plate will contact the Peltier coolers (with Artic Silver 5 for good contact). The image makes it appear as if it is rough but it is actually sanded very smooth.
Large black anodized aluminum heatsink with two thermally controlled computer fans on the back (Thermaltake 92 mm Smart Fans).
The Peltier elements contact the reverse side of the heatsink. In this image you can see the tapped 1/4 20 holes for mounting the heat exchanger as well as milled out countersinking to provide clearance for the heads of the screws holding the titanium plate to the acrylic.
Fits like a glove on top.
125 amp 12 V power supply I got on ebay for a ridiculously good deal ($80). It is used to power both Peltiers which at 12 at their peak (when you initially turn them on and they are still cool they draw the most current) they will draw around 40 amps total. After heating up their hot sides they each settle down to about 12 amps each.