Corsair HydroCool 200 Review

A Closer Look (continued)

This content was originally featured on Amdmb.com and has been converted to PC Perspective’s website. Some color changes and flaws may appear.

Unfortunately no filter was provided on the radiator air inlet so periodic disassembly and cleaning may be required. Optionally, you could install a standard 120 mm fan filter on the outside of the enclosure in place of the wire fan grill, like this. The outer plastic housing snaps on and off so the foam filter element can be easily cleaned.

The radiator is a double-pass, flat tube type, incorporating a large finned surface area. It is made from aluminum, which makes it very susceptible to galvanic corrosion if not protected by chemical corrosion inhibitors added to the water coolant.

Corsair includes a bottle of coolant liquid additive, which is a pet-safe formulation of automotive antifreeze (uses propylene glycol (non-toxic) instead of ethylene glycol (toxic)). This additive is required for its corrosion inhibiting properties. It is very important to use the additive in the HydroCool 200 liquid cooling system. Without it severe corrosion will quickly (in a matter of days) start eroding away the wetted aluminum surfaces and deposit corrosion byproducts on wetted copper surfaces. The first signs of this type of internal corrosion will be increased temperatures due to fouling of the waterblock’s micro-channels and visible sediment accumulating in the reservoir. Use distilled water and the provided anti-corrosion additive when filling the system.

A microprocessor based control and display panel is mounted on the front end of the external cooling unit.

Looking at the front of the panel you will notice several key features.
• Temperature display – shows the temperature of the HydroCool 200 waterblock
• SET button – used to set advanced features (alarms and diagnostics)
• C button – used to select ºC mode
• F button – used to select ºF mode
• TURBO button – used to force system into Turbo Mode (full speed fan)
• TURBO light – indicates system is in Turbo mode when illuminated
• Audible Alarm – (not visible) used for high temperature and low coolant alarms

Moving outside of the enclosure brings us to the heart of the system – the waterblock. The waterblock is made from nickel-plated copper and according to Delphi, incorporates a micro-channel design. Since the block is soldered together we can’t actually see inside, but from the exterior layout it appears likely that there are a number of very small copper fins and water channels connecting two plenum areas under each tube fitting. The block must also be internally symmetrical because the instruction manual says it doesn’t matter which way the tubes are connected to the inlet or outlet. (I have seen photos on the Internet of the HydroCool 200 waterblock’s internal features, which confirm these assumptions.)

The micro-channel design has the potential to efficiently transfer heat out of the metal waterblock and into the circulating water. Because of the small dimensions involved, it also makes the block very susceptible to fouling and clogging if the water coolant is not properly maintained.

The tubing used to connect the waterblock to the external cooling unit is clear 1/4” ID polyurethane (Ether grade) tubing. It comes pre-attached at the waterblock end, which allows the end user to cut the tubing to the desired length during assembly. This type of tubing is a little stiffer than the Tygon R-3603, Clear-Flex or Silicone tubing many of us are used to using.

The base of the waterblock appears smooth and flat (fine machining marks) but a quick lapping with 600 grit wet paper on sheet glass showed the block was slightly dished (low in the center); probably caused by stresses induced into the metal during assembly.

The final piece of external hardware is the small interface card, which installs in an empty PCI slot. This card does not actually plug into a PCI slot on the motherboard but instead receives power from an internal 4-pin Molex connector. There are two holes in the interface card mounting bracket to allow the waterblock tubes to pass out of the PC case and over to the external unit.

The interface card connects to the external cooling unit by way of a 24” long cable with DB-15 connectors on each end. Power and control signals are routed thru this cable. Both the water pump and radiator fan operate on 12 VDC supplied by the computer so there is no extra 120 VAC power cord required.

In addition to the power cable the interface card also serves as a connection point for the waterblock temperature probe and the Power-off control cable. This later cable is used to permit the HydroCool 200 controller to execute an emergency shutdown of the PC if the waterblock temperature sensor goes over 50º C (user definable).

OK, that pretty well concludes our tour of the HydroCool 200 external liquid cooling system. Now it’s time to do some testing.