TEC Water Chiller

[Titan151]

I recently picked up a water chiller on the e-bay. I was a little concerened that it might not be able to cool my system. It seems substantial in heat capacity. It's a titan150 thermo electric chiller (no compressor) and can cool 150 watts. The specs state it can drop the temp of 25 gallons of water by 10 degrees F. The reccomended water flow rate is 50-100 gph. I got this knowing I could always sell it back on ebay so I kept it in good condition. So far I haven't had much time to toy with it, but my initial results show it isn't working well with my set up. My question is, my pump is rated at 280 gph. If i shut the pump off the chiller easily drops the water temp down to 6 degrees c. I am wondering if a slower pump would allow more time for the water to chill thus reducing the temp. I have one and am going to try it out tonight. The other option is to use the chiller in some kind of loop with a seperate pump. This could amount to cooling the water in a reservoir or perhaps the radiator in a submerged container. I will have to toy with other options. It may be too early to jump to any conclusions as I have more to try. Anyone have any info on thermo electric chillers with no compressor? ANy help much apreciated.

[gruntledweasel]

Short answer:
The search function is your friend. Search the forum.

Long answer:
Welcome to the club. Search this forum for threads on Thermotek chillers, there's been a fair bit of discussion about them.

I'm assuming you are not running the chiller inline with a separate radiator (heatercore, whatever). If you are, the radiator is acting like a heating element, and needs to be taken out.

If this is a radiatorless loop (the TECs in the chiller have some kind of heatsink, but the actual coolant loop has no heat exchanger other than the chiller unit), your overall water temperature at zero heatload shouldn't be different from the lowest temp you can get with that chiller. If you're seeing a significant change when you shut down the pump, my guess is you need more insulation on the loop. The only thing that could be increasing your temp is heat absorbtion through insufficient insulation. Or you've got a pump that's putting out a dirty great heatload, and turning it off actually makes that much of a difference (unlikely).

Again, if the cpu coolant loop has no heat exchanger other than the chiller, time spent in the chiller shouldn't matter. It's just like a radiator. Time spent in the unit only matters if it's inline with a radiator. The only gain you'll see from making a separate loop for the chiller is reduced headloss (may or may not be balanced out by the increased heatload from a second pump).

Also, bear in mind that chiller performance degrades with heatload (opposite of radiators). As you add watts to the loop, the system deals with those watts less effectively.

[Titan151]

Thank you for the reply,

Yes I have much to learn about chillers. I was previously experimenting with several pelt set up's. This is my first trek into the chiller arena. Last night when I hooked it up I was debating on if I should hook up the rad (big black ice 2). I hooked it up. I thought it would provide more cooling but now I see it is simply exposing the cold water to ambient temps.

I will take it out of the loop and see how it works. One other trick I will try is to lower the temp of the unit below the 6 deegree set point. I am considering moving the built in thermistor and tricking the unit into thinking it is off by several degrees. This should be interesting although it may be dificult for this unit to get that cold. ack, all of this will of course come after I get it working properly.

[pHaestus]

If your chiller can only cool 150W, and your system is generating around 100-125W heat, then water temperatures would be around room temperature and CPU would probably be running 40-50C.

[Titan151]

Originally Posted by pHaestus

If your chiller can only cool 150W, and your system is generating around 100-125W heat, then water temperatures would be around room temperature and CPU would probably be running 40-50C.

My (CPU - XP 2500 Barton) Only puts out 70 watts max. If I remember correctly most CPU's are still below the 100 watt range. This will be something to take into consideration when it comes to adding any additonal water blocks to the loop.

[Titan151]

OK so with the radiator out of the loop i can get the temps down to about 18 degrees with the computer off. With the computer on I am getting a pitiful 45 degrees C. at idle. I must be doing something wrong. Like I said before, with the pump off the cooler drops the temp substantially down to around 8 degrees C. As soon As I turn on the pump it goes to about 18 or 19. I have a pump that is self contained in a reservoir. I supose this could be a problem as it is adding heat to the system. Right now I run from the pump to the cooler to the waterblock. (maze 4). I supose I am using about 5 feet of vinyl tubing. I supose I could try taking the pump out of the reservoir. I am starting to have doubts as to this TEC chiller. May have to hawk it on ebay for one with a compressor. Any input apreciated.

[gruntledweasel]

The heat output by the pump is not trivial. It could well be pushing your heatload into the range pH described. (how are you measuring temps, btw? watercooling is known for tricking motherboard probes into reporting higher temps than they should.) If the pump is inside the res, ALL of its rated power is going into that loop as heat.

I'd also do a finger-test at various points on the loop to make sure it's insulated well enough. If it feels cool to the touch, it probably could use another layer of insulation.

I don't want to discourage you from using TEC chillers (one of 'em is my current pet project!), but I will point out that there really isn't an advantage to using them over a compressor. If you don't mind the noise, something with a decent compressor may very well outperform the tec chiller.

If you want to dig deeper, you could work out the energy balance for the loop to see how much heat it's gotta be absorbing from the pump + surroundings, and subtract the number of watts the pump draws in current to get a rough idea of how much heat's being added to the loop through the tubing walls and such.

If you're up for a project, my own thread might be worth perusal. You could probably top my setup easily in terms of both efficiency and performance if you custom built your own chiller block.

edit: typos

[Titan151]

another layer of insulation? I think I will go check out the amature forums for a while. I assumed that the vinyl would insulate it (5 feet of it) I also have more tubing then I need so I could move things around a bit. OK so I will insulate everything, including copper on water block, and then see if that helps. If my temps drop somewhat I will then consider getting an in line pump. Since my pump is submerged and adding additonal heat. I guess I was under the assumption that insulation was nice to drop a few degrees but not needed. As for my temps, I have the sensor on the chiller, mobo, case, and one I placed under the chip. They tend to all provide somewhat accurate temps. Thanks for the help again.

[Titan151]

Here are some picks after initial insulation. I still need a little here and there. Not to mention deal with the submersible pump. Gonna lap the water block and then wrap up the exposed sides. Still not sure about this chiller. It was able to reach 6 C with no pump or pc. With pump it hit about 15, and with pc it is at about 30 while the pc is at 45. Much work still ahead. My goal is to reach an operational level of 0 C more or less. Once I get close I will take out mobo and prep it for condensation. I found a via aqua chiller on ebay for just a little more. It has a 1/4 hp comp in it. I saw at www.aquastealth.com that they sell this for PC apps as well as the standard aquarium app. Here's the gig. They also sell a "modified" version that goes to zero and can handle cooling your NB, Vid chip, and proc all. This is the same unit but simply modified by them (Becooling) I figure they just alter the temp adjustment so it cools lower then any aquarium owner would ever want. The point of all this is that I may pick the standard one off of e-bay. It would be nice to know what they did to make it go cooler. I assume that whatever they did was minor since the price difference between mod and stock is like 20 bucks. Anyway here are some picks of my setup still needing work and after typin up to a lame 46 C (hotter then my pc used to be with wc only)

[Titan151]

OK so I have finished insulating this thing. Unfortunately I was going to lap the maze 4 but am all out of fine sand paper. Also went to put on the artic 5 and only a tiny bit was left :shrug: . Oh well there is always tomorrow. So I did a quick lap with the 600 grit. (when i got the maze 4 it needed to be lapped badly). Slapped on some low quality goo from my parts bin and hooked er back up. Let the chiller drop down to 5 C then turned on the pump. I see an improvement but not too much overall. I did notice one problem with this chiller. In an effort to keep the in and out ports below the electrics they used to 90's that allow you to connect to the intake ports below the unit. These then run up and into the chiller. they pass rediculously close to the hot side of the sink so I insulated them as well (they are inside the chiller case so I had to pop off the back panel). So right now I am at 28 on the chiller, 43 on the mobo and 39.5 on my external sensor. (degrees C of course) So all in all not lookin to promising even if i remove the submerged pump and use an inline. I doubt it could be adding that much heat. May give me another 6 degrees or so. I'll let this thing run over night and check in the morning. Perhaps I will awake to a frozen block of ice.

[Bertz_maru]

why dont you try cooling the water with the pump on but with the computer off? see how cold your water gets like that.. and then if its cold enough turn on your comp.... just a thought...

[pHaestus]

you really need some more technical specs of the chiller. When you say 150w cooling at what coolant temperature? If it's 150w at -20c coolant then something's dreadfully wrong. If it's 150W max cooling (resulting coolant is room temperature) then everything's working fine and your chiller's just maxed out.

I assume it's the latter and I can't understand why you expect something more out of this unit? Simplify the system in your mind: You are putting only slightly less heat in than the chiller can pull out so water temperatures should end up slightly below room temperature if you run the unit long enough to reach equilibrium,

You're going at it from opposite side of equilibrium (no heat source and all chilling then apply heat) and so it looks like the chiller isn't working.

Of course the unit could need a charge or something it's hard to know without more specs.

[Titan151]

Originally Posted by Bertz_maru

why dont you try cooling the water with the pump on but with the computer off? see how cold your water gets like that.. and then if its cold enough turn on your comp.... just a thought...

heh, Yeah i tried this with the chiller at 6 degrees C. and the pump off. No go. It would be interesting to try a reduction in the flow rate. As is I don't think it would make much difference.

Ph - this is a TEC chiller so it has no comp. I was likely dreaming when I thought it would get near zero temps. It is rated to reduce the temp of 40 gallons of water by 10 degrees C. It consists of a 24 volt power source and a tec that consumes something close to 200 wats of power. This said I was hoping it would be able to cool the water like a TEC place on the chip. ( of course with less effective results) I picked it up for 180 bones and will simply put it back on the ebay for sale. It will likely work much better for an aquarium application.

I am going to try out an Aqua Logic unit similer to this one here. www.aquastealth.com If you search through that site you will see that they sell a modified version of it for about 30 bucks more. If I can figure out how they mod it and duplicate it I should be able to hit something close to zero. I am betting it was a simple mod involving a reduction in the minimum temp the unit operates at. At a minimum I am betting that I could simply trick the temp sensor into being 5 to 10 degrees above the actual temp. Then monitor the actual temp using an external sensor. Thanks to everyone for their imput as this has been a learning experiance.