PCA Forums

Ok.. I'm thinking about water cooling my next rig and have a few questions. I think it's really neat, but the cost is a little beyond my justification for cooling.

1. ) I'm currently using an SLK-900A w/92MM fan and I'm running between 29*C and 40*C at full load depending on the temperature in my room. Lowest temp of 29* was a few night ago when it dropped to 40* and I don't use a heater as I like it cold. During the winter I forsee a lot of low temps. Will I benefit any from watercooling? Obviously there's the reduction of noise due to the decrease in the number of fans. But the noise, which there is very little of, doesn't really bother me.

2. ) If I was to construct my own system, (everything but the GPU, CPU, and HD blocks) what parts should I look for? I have heard of many using Heater Cores from cars for the radiator (works for me ) and just getting the hose at the hardware store. Any particular Heater Core I should look for? I'm kind of wanting to go with a red color scheme, so it would be nice to find all the parts in red.

3. ) What is the minumum GPH the pump should push? Also, I've noticed that they lose power for every 5" or so they have to push the water up, this make sense. But why not mount the pump and resivoir towards the top of the case so that the water is pushed down instead of up? Or does the pulling the water up kind of balance that out? Should I get a 12V pump or a 120V? I know that a 12V pump probably pulls a lot of power and would be a strain on the PSU. It wouldn't be difficult for me to rig up a a standard power outlet on the back and then make a double ended Male plug that I could plug into the power strip and then into the socket to power the pump. I'd just be worried about possibly creating a ground loop doing that? (I'm going to post another inquiry about ground loops later)

4. ) I've been looking at some CPU Blocks on SVC and I like the Zalman even though it's blue, they all seem to be blue, black, or that clear green, and it said it accomodated fittings of 8x10mm 8x12mm and 10x13mm or something like that. Does AxBmm represent the following? A=ID / B=OD? I'm planning on "trying" to do this in a very structured way using Hot water PVC. Yah, it's gonna take some work, but I want this to look good, and be different. The hardest part in doing that will be putting it together in a way that won't require me to cut the PVC later to get it out of the case. I plan on using some small lengths of hose to connect the PVC to the waterblocks and some smaller hose clamps. There will also be a spot toward the bottom of the assembly that will be constructed with clear hose to check for sediments and so on. If this proves to be too much of a hassle, then I'll just go with clear tubing and red UV dye or something.

Well, those are pretty much my questions.. TIA eGo

1. Those temps are pretty good. Watercooling probably won't get you much better than that. However, if you are reading the temps from a thermistor mounted inside the socket instead of an internal diode in your cpu, the temps will be affected by the airflow around the socket, which tends to cool the thermistor a bit.

2. If you build your own, spend money on the waterblock and pump and try to scrimp everywhere else.
Car heatercores are the way to go. If you want to put the rad in your case, a Chevette heater core can be had from Autozone for less than 20 bucks and will fit in most cases. If you put your rad in a box outside your case, you can use a larger core. I got one from an 86 mustang on flea bay for 8 bucks.
Pumps - Eheim pumps are the best and Supreme Aquamasters are also good. Tubing - use silicone or tygon tubing. You can get this stuff from McMaster-Carr - www. mcmaster.com or US Plastics - http://www.usplastic.com. Both places also sell polyethelene or nylon barbed fittings and plastic clamps. For reservoirs, I use Sullivan brand RC airplane fuel tanks from Tower Hobbies.

I like to get 120mm fans from electronics surplus places like http://www.goldmine-elec.com

Vinyl tubing gets stiff with age and is not as flexible as silicone or tygon. I would stay away from it.

You can paint a heater core if you so desire.


3. Pump GPH - I would say 180 gph is a minimum. Going beyond 350 gph has drawbacks, including increased pump cost, size, noise, vibration and heat. It doesn't matter where you put the pump, whether it is on top or the the bottom, the water will still have to be pushed "uphill" at some point. Twelve volt pumps are hard to find and not reliable. Most are not rated for continuous duty. Go for an AC pump.

4. Your intuition about fittings is correct. I don't know if 10 mm ID is the same as 1/2 ID, but most watercoolers eventually go to 1/2 tubing for flow rates. I don't know how the Zalman performs versus other blocks but it does have the advantage that you can take it apart to clean it.

As far as using rigid PVC tubing, I would advise against it. You will have enough space and access problems with flexible tubing. Rigid tubing is a nightmare unless you feel you would like to drain, disassemble and refill everytime you need to to swap something out of your case.

Feel free to PM me with any questions. I have been doing watercooling for years.

Thanx for all the input! That will be very helpful. Which water block are you using? I was going to ask if you could paint the radiator, but it seemed kind of like a stupid question, because painting it, I thought, would insulate it reducing cooling. It's good to know it can be painted. As far as the temps go, I'm getting those temps from the "probe" that is on the 8RDA+. It's not like the normal temperature diodes. It looks just like a temp probe on a compunurse or other probes. I haven't taken the time to mount a probe on the CPU itself yet. But, as you've said, it won't provide a whole lot of difference in the temps and will potentially cost more than another SLK-900A for my current mod. So I may very well just stick with what I had originally planned. Thanx again! eGo