Water Cooling De-Mistified

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I regularly receive emails asking various questions about water cooling (“How, Is it safe? What should I buy?”). Maybe these thoughts will help.

About 9 months ago, BeCooling sent me a sample of their complete CPU water cooling system for me to review. I used water cooling with peltiers, but that was with a cooler full of ice-water; not too practical for daily use. The BeCooling unit was under-whelming – “Do I really want to put this in my system??”

After filling it and testing it outside the case for leaks, I hooked it up – with more than a fair degree of anxiety. Turned it on, waited for the CPU temp to go up, didn’t go up, and I have not looked back since. Since then, I have personally tested more water cooling stuff lately than I ever thought would be available, and no doubt more is coming. With CPUs pushing well beyond 1 GHz shortly, overclocking and controlling heat (which go hand-in-hand) will increasingly turn many to water cooling.

So, in an attempt to overcome some reluctance to take the plunge (ouch!), here’s my thoughts on it:

What Are The Advantages?

I think there are two primary advantages:

  1. Efficiency: There is no arguing that water is orders of magnitude better at capturing heat than air. We have all experienced the quest to move more air for better cooling – larger heatsinks and faster fans. With CPU sizes diminishing drastically, the physics of moving a lot of heat from a small area to an air-cooled heatsink raises the specter of diminishing returns.

  2. Quiet: Higher cfm fans mean more noise. I use my systems at least 5 hours/day, so low noise is real important to me. Many of you have Alphas with YS Techs, so you know what noise is. With air cooling, I use one 120mm 30 dBA fan with a 92mm rear fan – that’s it. My CPU averages 2-4 C under ambient with normal use, and maybe 5-7 C over ambient under stress. Hard to argue with that.

What About Leaks?

I get this a lot. CPU water cooling does not build a lot of pressure; there is no real heat and no extreme pressure. I use hose clamps on all fittings and cannot pull them off. With no extremes of heat, pressure or vibration, a water cooling system in a computer is in about as benign an environment as you can find. Nothing is infallible, but the odds of catastrophic failure are very low.

If you are super concerned, use distilled water – doesn’t conduct electricity.

Do I Have To Modify My Case?

Not necessarily, but realistically – Yes. You can run an open case and keep the radiator outside the case, but I don’t think this is a desirable long term solution. The alternative is to use a tub of water rather than a radiator, but if space or portability is an issue, this is not going to work.

What Do I Need?

There are four main elements:

  1. Water Block: There are now a number of places selling copper, aluminum and plastic water blocks which we have tested and work very well. Copper, in general, cools better than aluminum, but better designs (e.g. Tidal Pool) have closed the performance gap. Plastic blocks are also coming on strong. Prices range from $20 – $40.
  2. Radiator: These are usually small units that are used for transmission or oil coolers. As such, they are pressure tested to something like 100-200 psi – the potential for a leak is nil. Expect to pay $20 – $60.
  3. Water Pump: Two types are used: Submersible and In-Line. Submersibles require an additional element – a water reservoir. This takes up some space (usually a box about 4″ square) and can be mounted in the case. An In-Line pump requires no reservoir. Pumps are 110 volts so they require a separate plug.

    Personally, I prefer an In-Line system – simpler and less bulk. Water Pumps are typically those used for small fountains and aquariums. Expect to pay $15 – $70, depending on its rating in gph (gallons per hour) – the more gph, the more expensive.

  4. Fan: You have to push air through the radiator – 120mm fans are the best – lots of air, not too much noise. The higher the cfms, the more noise. Expect to pay from $10 – $30.

How Do I get Started?

First, what are you trying to accomplish? Let’s assume you are interested in better cooling and with less noise. Next, how handy are you?

If you are really not that handy, then go for a complete system – water pump, water block, fan and radiator. These range from about $60 up to about $200. The advantage is you should get everything you need – hoses, clamps, water block, radiator, fan and water pump with reservoir. If you go this route, make sure you get the little stuff (e.g. clamps, hoses, mounting clip etc) as well as the main pieces.

If you are handy and have some of the necessary parts, then buy the pieces you need and roll your own – it’s not rocket science. Test whatever you put together outside the case (run it overnight in the tub) and, if no leaks, mount it in the case and off you go.

But What If I Don’t Have A Lot Of Money For This?

Then scrounge.

Take a trip to your local auto scrap yard and ask for a heater core, oil or transmission cooler; these are the small radiators that can be used for CPU cooling. Cost – about $10. Or use a copper coil radiator – I found lots of copper coil at the metal scrap dealer. Or use a picnic cooler as a water reservoir and throw ice in it – it takes a lot to heat it up.

For a water block, I have seen all manner of things used, including a contact lens case! Browse around Overclockers and you will see some very common, inexpensive materials quite effectively used for a water block (check out Surlyjoe’s stuff).

Fans are cheap, and if you are lucky enough to have a metal scrap dealer that gets computer junk, you can pick up a large one for less than $5.

I would not compromise on the pump, though – that’s pretty critical. Considering you can get a good one for about $25 and you can use that in an upgraded system, it’s not lost money. If you’re really pressed, go to some yard sales and see if you can pick up a a good aquarium pump – you’d be surprised what you can find.

With luck, I think you could get a good system going for less than $50.

But What If The Pump Fails?

Same thing that will happen if a fan on an air-cooled heatsink fails. If you use a CPU idle program and the system is at rest, nothing. If under stress, maybe a cooked CPU unless you use Motherboard Monitor with Shutdown enabled. Once you hit a pre-set temp, the system shuts down automatically. Basically, if you are careful and have the right stuff set up, catastrophic failure is unlikely.

Water pumps are designed to run continuously for something like 2-5 years, depending on quality. For a system on 5 hours/day, I would be surprised to find a failure in five years.

Do I have To Add Water?

I have not added water since I started. These systems are basically sealed, so evaporation is nil.

Is That It? Sounds Too Easy.

Well, it really is not that hard. What’s hard is that it’s a new way of doing things and the impetus for change, for many people, is not high enough yet to overcome the “change hurdle”. However, I’m sitting here typing this with an ambient temp of 27.6 C and my CPU is 22 C (PIII 600E @ 800 MHz) and I can barely hear the fans. That’s enough for me.

What Would You Recommend?

Put me on the spot! My feeling is simple – spend the money for good components, you’re going to use them a long time. Here’s my system right now:

System One

It consists of the following components:

  • Be Cooling Copper Water Block
  • Be Cooling Radiator
  • Panasonic 120mm Fan
  • Eheim 1046 In-Line Water Pump
  • GXT912 ATX Server Case

Note: For mods to the case go HERE

If I were buying today, the BeCooling radiator still seems to be the best for the money; Tidal Pool’s aluminum water blocks and Overclock-Watercool’s plastic blocks may be a better price/performance choice. The Danner PondMaster 1.5 is a very good submersible pump that will do the job. For a peltier water block complete with insulation, the best I have tested is the Swiftech unit.

I have tested a lot of components, so I would recommend you check out our reviews listed under “Water Cooling” and any others you find before buying.

Where Can I Find Stuff?

What follows is a list of companies which sell complete systems and parts; note that many of these sources are small businesses – products may not be as polished as you might expect. I can only counsel you to be particularly clear to each vendor about what you expect in terms of quality and completeness of what you might buy and pay by credit card – the ultimate dispute arbiter.

For additional radiator and water pump sources, go HERE

And yes, I know it’s spelled “De-Mystified”.


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