Converting to Water Cooled CPU

This article describes the change over from air cooling to water cooling an Intel QX6800 Extreme quad core CPU. (Not overclocked)
Inside the case there are several components, each contributing to heating up the internal environment.
The CPU is fitted onto an Evga nForce 680 SLI 122-ck-NF60 mother board. An Evga GeForce 8800GT 640Mb Video card and 4Gb OCZ DDR2 800mhz ram together with 2 x 500Gb hard drives, a Soundblaster Audigy 2ZS and a Jeantech Storm 700w Sli/cross-fire PSU complete the round up of the main sections of the home brew computer. The ‘bits & pieces’ are fitted inside a Jeantec Gaming Development Aqua Case.
The original CPU cooling was implemented by a Zalman CPNS9500A. After a few months, the author decided to convert the air cooling on the CPU to a water cooling method.
The author was faced with the choice of purchasing the individual components such as a water block, pump, radiator, fans, flow meter, alarm unit, tubing and anti-freeze/anti-corrosion fluids or a complete kit of parts. After looking at the costs involved, a Zalman XT Reserator price was not very much more than a set of top quality components. Considering that the Reserator also features three alarms;  coolant flow, over temperature and fluid level, it represents peace of mind and good value.
A Zalman Reserator XT kit was purchased as this included all the components and accessories needed to complete the job from start to finish. The kit included a Zalman ZM-WB5 CPU Water-block.
The first impression on opening a very well packed box was the size of the Reserator. It was much larger than imagined. However, its size gives massive thermal capacity and houses two radiators. The body of the unit comprises of a custom made aluminium extrusion which in itself has the coolant flowing through, thus contibuting massively to heat exchange to the outside world.
The kit was comprehensively equipped:
[IMG]Included in the kit[/IMG]
Fig 0: Contents of the Zalman kit.
The kit includes mounting components for Socket 775, Socket 478 and AMD Socket AM2/754/939/940. Also included is 0.25 litre bottle of Zalman ZM-G300 Anti-corrosion fluid and a comprehensive user manual
One of the advantages of using a Zalman cooling system is that the Zalman fan and the water-block share the same mounting hardware. This enabled the replacement of the fan with the water-block a simple task. Otherwise the motherboard would need to have been removed to fit the reinforcing mount underneath.
Thermal compound:
Not all thermal compounds are equal. The thermal grease that is supplied with the kit was not used. Instead Arctic Silver 5 thermal compound was used to ensure the best possible transfer of heat from the CPU heat spreader to the Zalman water-block.
Coolant Additive and Water:
Zalman anti-corrosion fluid must be diluted with distilled water. In the UK distilled water is relatively hard to find in ‘local’ shops. The author visited many shops asking for distilled water. In all instances the shop assistant gave what they thought was distilled water but turned out to be de-ionised water.
Battery top-up water used to be distilled but is now de-ionised – do not use.
In the UK supermarkets, distilled water for steam irons is distilled but contains other chemicals and perfumes. The author does not know if this liquid is OK to use as a dilutant.
Eventually, real distilled water was located on Internet for delivery in 5 litre bottles at a reasonable cost.
The Conversion process:
Original Zalman Fan Unit
Fig 1: The original Zalman CPNS9500A heat sink and fan.
Only two screws hold the heat sink & fan assembly onto the mounting hardware. After the removal of the heat sink, all of the old thermal compound must be carefully removed.
There is a special fluid for removing Arctic Silver 5. However, the author used a single drip of ethyl alcohol on a cotton bud to soften the old material.
The CPU must be clinically cleaned, ensuring that no foreign matter such as dust, hair or even skin flakes are present. Using a cotton bud will, more than likely, leave very fine hairs behind. After much cleaning, a can of compressed air was used to blast away any invisible debris before applying the Arctic Silver 5 compound and mounting the water-block.
ZM-WB5 Water block
Fig 2: Zalman ZM-WB5 CPU water-block.
The Jeantech case has the advantage of the sides are hinged at the bottom and can be opened out flat to give very easy access to the motherboard.
Installing of the water-block must be done with care. It is important to install the water-block in the correct orientation. Note that one of the pipes is dead centre and the other is offset.
The one in the centre is the cold coolant inlet and the other is the warm coolant outlet. The Outlet pipe must be physically higher than the inlet when the case is closed. This is to ensure that when the system is started, that are no air pockets in the water-block to cause hot spots but more importantly to allow for natural thermal flow in the event of pump failure.
Mounting arms
Fig 3: The mounting arms.
Once the mounting arms have been fitted to the water block, they are held down by two screws. The arms are, in effect, cantilever springs and exert quite a down force onto the CPU heat spreader. This aids the settlement and bedding in the thermal compound. Arctic Silver claims that the efficiency of heat transfer improves over a few days of usage.
Other heat generating components
Fig 4: Showing the adjacent heat generating components.
By removing the heat from the CPU to outside the case, the resulting drop in internal temperature will have an additional benefit in helping the other heat generators to run at a cooler temperature too.
Internal layout
Fig 5: Internal layout.
Zalman supply a nice I/O Bracket (A). This allows the pump cable (B) and the coolant pipes to enter/exit through rounded apertures (C). The rounding of the coolant pipe apertures ensures that there is no chaffing on the pipes. A nice touch.
Tubing clamps
Fig 6: Tubing clamps.
Some enthusiasts recommend using jubilee type clips that clamp the tubing by tightening a screw. The author found that the tubing was a very tight fit. The clips supplied with the kit were very strong and certainly put enough pressure on the tube ensuring a watertight seal.
One tube fitted
Fig 7: One tube fitted.
The I/O bracket was mounted in the case. At the same time as mounting the bracket, the DC cable was also installed. The cable was plugged into a fan connector on the motherboard.
Four metres of PVC tubing was supplied with the kit. This was more than enough to install the system.
General view of layout
Fig 8: General view of layout.
The tubing was not cut at first. The two ends were fed through the I/O bracket and fitted carefully to the water block.
Degassing tube
Fig 8a: Degassing.
Before the tubing from the water blocks is connected to the Reserator, it must be filled with coolant and air purged from the pumps and radiators. The kit was supplied with a short ‘degassing’ tube for that purpose. The connectors on the Reserator are quick release non-drip types which means that the tubes can be removed and replaced without having to drain the system.
The supplied coolant was diluted at 1:4 ratio, making 1.25 litres.
Initially only 1 litre was poured into the Reserator. The Reserator was then powered up and after following the instructions, the pump was primed and all air was purged with no more bubbles appearing in the tube. The remaining .25 litre of coolant was then poured into the unit.
When this was achieved, the degassing tube was disconnected and the quick release connectors were removed.
Rear connections
Fig 9: The intlet, outlet pipes and the power connections.
Once the location of the main unit was decided, the main tubing was cut to length, with a few inches extra to facilitate moving about.
The quick release tube connectors to & from the CPU water block were fitted and plugged into the main unit.
Watching the water block for leakage, just in case, the unit was powered up to purge the tubing and water block.
It should be noted that Zalman supply a short ‘jumper cable’ which when following the clear installation instructions, allows the complete water cooling system to be powered up without powering up the motherboard.
Tubing & water block filled
Fig 10: Tubing and CPU water block filled.
The author ran the system for a couple of hours with the case open. There was no sign of any leaks or bubbles in the tubes.
Zalman Reserator in action
Fig 11: The Reserator XT in action.
The bottom temperature reading is the ambient of air entering in the radiators. The top temperature equals the coolant temperature. These readings can be displayed in Celsius or Fahrenheit.
The ‘volume’ knob controls the fan speed when it is in manual mode. In automatic mode, it has no effect.
The bottom three buttons, left to right: C or F readout, Automatic/Manual selector and LEDs on/off.
Being powered by the motherboard the unit is switched on & off with the computer.
Completed setup
Fig 12: The completed setup. Much quieter.
TIP: Note that the computer is standing on a piece of carpet cut to size. Placed upside down, it assists on making the computer easily moved without scratching the surface of the desk.
The Reserator XT is more than capable of tending to the cooling needs of most computer configurations. It is possible for it to supply coolant to other heat generators. If this is done, it is important to supply the coolant to the appropriately fitted water blocks in the following sequence:
CPU water block first, then Northbridge water block followed by the VGA water block and RAM water block and return warm coolant to the Reserator.

 
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