Water Cooling a PC


Introduction: Water Cooling a PC

About: The official instructable for Popular Mechanics magazine, reporting on the DIY world since 1902.

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Computers get hot, and they must be cooled. Your average store-bought PC uses a system of fans to pull heat off major components such as the CPU (central processing unit), graphics processor and hard drives. Then the hot air is blown out the back of the machine. That works just fine for most computers doing most jobs. But it's not always ideal, and it does nothing to impress your friends. The other option for dissipating heat is water cooling, or, really, liquid cooling, in which a combination of distilled water and propylene glycol is piped through the guts of the machine. Installing a liquid-cooling system isn't all that difficult, though it can be intimidating. Who can really benefit from this hot-rod project? Mainly, computer users who like to overclock their PCs and run them hard for gaming applications, video processing, sequencing the DNA of Amazonian tree frogs, and the like. Such people often work their processors into a heated frenzy, forcing the fans to run constantly and noisily.

Since liquid transfers heat more efficiently than air, water-cooled PCs can run significantly cooler. (In tests at Popular Mechanics, our liquid-chilled rig ran at 62.6 degrees Fahrenheit at idle - 27 degrees colder than a similar air-cooled computer.) You'll also be able to remove one or more fans, so your water-cooled system will run more quietly. Koolance, Thermaltake, Zalman and other companies sell a variety of water-cooling kits at prices ranging from $150 to $470. (You also can buy the parts piecemeal, but we suggest using a kit for your first water-cooled setup.) A water-cooling system includes a water block, hoses, pump, reservoir, and an external or internal radiator. Make sure you buy a kit that fits your PC's motherboard. It took us about an hour to hook up a Zalman Reserator 2.

Step 1: Prepping Your PC

Preparing your machine is the hardest part. Before you can hook up your water-cooling kit, you must remove your computer's motherboard. That means opening up the case, and unplugging all cards and cables from the board. Make sure whenever you unplug cards and cables, you pull from the connector, not the wire to keep the two from ripping apart. (Note: Take careful note of the setup, as you'll have to reconnect everything later.)

Step 2: Remove the Heat Sink

Once the motherboard is loose, unclip and remove the heat sink. This will have a fan and is in the center of the chip. Make sure not to rip the chip straight off the motherboard. Use a gentle twist and slide motion because the thermal paste already on the chip makes a tight bond. Then clean the top of the exposed chip with an alcohol wipe and apply thermal paste (a conductive metal- or silicone-based grease that should come with the kit).

Pictured here: The heat sink after it is removed, cleaned and the water block is attached (see step 3).

Step 3: Install the Water Block.

Install the water block using the provided mounting bracket. The mounting bracket will sandwich the mother board with a bracket on the bottom and top connected with two screws. As always, and especially with electronics, don't over-tighten the screws.

Pictured: Hoses attached from your water pump and radiator (see step four) will take away heated liquid from the water block and replace it with cooler liquid.

Step 4: Put Your PC Back Together.

Next, put the motherboard back in the case, and reconnect all cables and cards. Use the supplied clamps to attach the hoses to the water block. If your pump and reservoir are separate components, you must run the hoses from one to the other and then into the radiator. (Our Zalman setup was easy to work with, as all of these elements were combined in a single external unit.)

Pictured: Clamping the hoses to the water block is easy –connect one hose from the water block to the pump and one from the water block to the radiator.

Step 5: Turn It On.

Now, hook up the pump's power cable to the connector coming from your PC's internal power supply.

Step 6: Check for Leaks.

Finally, fill the reservoir with the distilled water/coolant mixture and prime the system, checking all connections for leaks (glycol inside tubes–good; glycol outside of tubes–bad). If everything is sealed tight, you're good to go.



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    OK, please test it with your board out and only the loop on, that way you avoid shorting out your stuff. also use paper towels when testing, better safe than sorry

    Nice! I get your magazine, but i didnt realize you guys were on ibles!

    1 reply

    lol me too

    Im thinking about doing this...
    I have a few questions...
    1. could i use a peltier in a separate reservoir to cool the liquid?
    2. could i use non-conductive oil in the setup, as the liquid?


    5 replies

     you are a genius! non-conductive oil, like they have on electricity substation cooling units. I would have never thought of that :D

    The thicker viscosity of the oil might put a strain on the pump and cause it to fail sooner. That being said, oil would probably be a great alternative.

    try antifreeze or alcohol in it.

    Well, some oils have a near water viscosity so it would be fine.
    But i do see your point.

    =) Love to be of help.

    you buy special water blocks for them off a site like newegg or xoxide

    Nice ible!
    What case is that there?

    Daniel =)

    my computer tech class did something kind of similar, except they just took a fish tank, built the computer inside, and filled it with mineral oil.  it works perfectly, and the mineral oil does an excellent job cooling it.


    I dont like it becase it is COMPANI maked not a his made

    Most of you are don't seem to know what you are talking about. Leak check before yes, but after with components off to check for leaks while installing. Secondly water cooling works amazing, and if you are that worried you can get non conductive liquids (some made for watercooling some not) to put in the system. Thirdly you are way better off building a watercooling system from components instead of a kit like that. Also peltiers work nice however then you have to waterproof the motherboard because of possible frost, and peltiers suck up a lot of power so it pretty much requires a second power supply to be of any use, thirdly you still need a water cooling system to cool the peltier or you will end up just heating your processor more...

    1 reply

    Or a large heatsink/fan combo.

    could you use oil (non-conductive) instead? How much more effective is water? Nice Instructable

    1 reply

    de-ionized water is non-conductive. The biggest advantage of most oils is that it does not evaporate like water would at 100C. (Although, creating steam steals a lot of heat). Even De-ionized water however will have some gasses dissolved in it, where the oils will have a much lower concentration of gas absorption.