After trying various air cooling combinations and not getting the results I wanted, I started researching water cooling. I was uneasy about putting water in my valued computer, but after doing all the research I felt confident I could pull it off. I didn't want to spend $125.00+ for a "boxed" unit as I felt I could do better with my own design. This article will be highly detailed with part numbers, prices, and pictures of the process. After a month of research, two weeks of collecting parts and designing, and 4 days of building and testing I'm happy to report success.

Everyone knows that water cools better than air, but I wanted to know just how much better. After searching the web to no avail, I decided to post my question in the Overclockers.com Forum. Steve Bage was nice enough to answer my question. He informed me that the heat transfer coefficient of air is 0.02 W/m^2K and the heat transfer coefficient of water is 0.6 W/m^2K where W = watts, m^2 = square meters, and K = degrees Kelvin. From the math you can see that water is 30 times more efficient at transferring heat than air.

I chose a BE COOLING's Jagged Edge Copper Water Block and BE COOLING's 6.25" X 5" Copper Core Radiator. Copper provides the best heat transfer properties for the money. If you decide to mix metals, such as an aluminum water block and copper core radiator, make sure to use some type of additive in the water to keep everybody happy. If no additive is used, electrolytic corrosion can occur that will destroy parts.

I decided to go all out and lap the block. From BE COOLING it was pretty flat, but I went through 600, 800, 1000, 2000, and 3000 wet dry sand paper. It tended to get smoother when used dry vs. wet. As you can see, it now has a high mirror finish:

To keep the radiator cool I used a Sunon KD1212PMB1-6A fan. This 120mm X 38mm unit produces 108 CFM, (cubic feet per minute) at 3100 RPMs, (revolutions per minute) 6.8 Watts, and 42 dBA (decibels). To cut down on noise when full fan speed isn't needed, I decided to wire in a rheostat, Radio Shack part # 271-265B to control the fan RPMs. Rheostats are like variable resistors in that they limit current to a DC device.

For a finished look, I used a Radio Shack knob for the rheostat, Radio Shack part # 274-403A. This rheostat is rated at 3 Watts, and the fan is rated at 6.8 Watts. I figure this won't be a problem as the rheostat wouldn't see the full 6.8 Watt load unless I turned it down far enough to practically stop the fan. This will never occur. Half way would be 1500 RPMs which would equal around 3 Watts and I'll likely need more speed than that to keep it cool. I guesstimate 2500 RPMs to be the sweet spot.

To pump the water, I decided on a MAXIJET 1200 submersible pump which I picked up at a local aquarium shop. It has a 295 GPH rating which is plenty. Keep in mind when choosing a pump that pressure decreases as pumping height of the water increases. The MAXIJET came highly recommended for reliability.

It's a magnetic drive unit, which means the only moving part is the impeller. I didn't want to have to remember to plug in or turn on the pump each time I used the computer, so I wired it into the power supply using a Radio Shack relay part # 275-218C. Information on how to wire this and the rheostat can be found HERE.

For a reservoir, I used an underground 4"x4"x4" waterproof electrical box. The pump fit perfectly inside this box and it is 100% watertight. I drilled two ½" holes in the top of the box for the 3/8" brass barbs for inlet and outlet and one 5/16" hole for the pump's power cord. I drilled the holes just slightly smaller than the threaded end of the barb so it would cut threads into the top of the box.

I sealed around the barbs with some black RTV silicone and put a rubber grommet (Radio Shack assorted grommets part number 64-3025A size ¼") around the power cord. The grommet was a tight fit, so I used rubbing alcohol to help the power cord slide through. Once the alcohol evaporated it created a watertight seal.

I mounted the box to the bottom of the case with four screws (#8x32x1/2") and nuts and isolated it from the case with rubber washers (# 00 flat sink washers) to deaden any noise from pump vibration. Clear 3/8" ID vinyl tubing and stainless steel hose clamps were used for all connections. Approximately five feet of vinyl tubing is needed and 8 hose clamps. The electrical box, brass barbs, screws/nuts, rubber washers, vinyl tubing, and hose clamps were all purchased at Home Depot.

Mounting the water block to the processor was the greatest challenge.

I looked at the various systems available and they were either too expensive or didn't look sturdy enough for my needs, so I decided to make one myself. I measured the block and the holes around the processor of my Abit KT7AR.

I decided to make the hold down 3" X 2¼ ". I liked the plexiglass or lexan look, so I made yet another trip to Home Depot and looked for ¼" thick plexiglass. They had it in 18" X 12" sheets, way more than I required, so I asked if they had any scrap from cutting these sheets. My lucky day - they had a scrap piece and gave it to me free of charge and let me cut it to the size I needed using their machine.

I had enough to make 6 mounts should the need arise. My design is similar to the one Danger Den offers, but I didn't want to have to take the system apart to remove the mount, so I made a channel in mine to allow it to slip on and off around the barbs.

I drilled four 3/16" holes in the plexiglass for mounting, and one 7/32" hole for the ¼"x20x2" nylon bolt that would apply pressure on the block. Use sharp bits for drilling plexiglass to avoid chipping. I then cut ¼"x20 threads in the center hole. I made two mounts, one was a template to make sure everything lined up and to ensure I got the pressure right above the processor core. The ¼x20x2" nylon bolt can be found at Home Depot.

On the finished product, I sanded the edges of the plexiglass with 1000 grit wet dry sandpaper (used dry) to make them clean and smooth.

I used nylon thread stock from Mc Masters (#10x24) to mount the hold down to the four holes around the processor in the motherboard. I cut four 3" lengths out of the 24" thread stock and put #10x24 nuts on one end with a dab of glue to make sure they didn't come loose, then turned them until 4 threads were showing. I put these through the four motherboard holes then put #10 nylon washers and #10x24 nuts on the front to hold the thread stock in place.

I then threaded four #10x24 nuts down to act as a support, making sure to measure all four to get them even. Then the plexiglass is mounted and four more #10 nylon nuts are threaded down to provide support on the top. The #10x24 nylon nuts and washers can be found at Home Depot.

J. Orrand