Zalman Reserator 2 Fanless Water Cooling System Review

Main Cooling Unit (Cont’d)

The center section of the Reserator 2’s main cooling unit consists of five extruded aluminum heat exchangers plumbed in series.  Liquid coolant flows thru a center channel in each of the heatsinks and transfers heat into the aluminum fins where it is then dissipated into the surrounding room air via natural convection cooling.  The vertical orientation of the heat exchanger fins helps maximize natural convection airflow. 

The aluminum heat exchangers are black anodized, which along with the corrosion inhibitors contained in the coolant, helps minimize corrosion.  They interlock together and the entire assembly is held rigid by the top and bottom covers.

The rear tower section is an extruded aluminum reservoir that is clear anodized and contains a small AC pump in the bottom.  It features vertical fins, which increases the total surface area for added passive cooling.  The top cap is sealed with an O-ring and must be removed to fill or add coolant to the system.  There is a small vent hole in the top of the cap to insure that pressure inside the reservoir equalizes with the ambient room air pressure.

Zalman uses the same Eheim 1000 Compact Pump that was used in previous Reserators.  Eheim has a good reputation for producing quiet, reliable pumps.  The Eheim 1000 is a small AC pump and comes in either 115V or 230V AC versions.

The pump is mounted upside down with the discharge port sticking down into the base of the rear tower section.  Water flows into the reservoir thru the small hole beside the pump.

Eheim 1000 Pump (Reserator 1)

The Reserator 2 comes with 4m (12′) of 8mm (5/16′) ID clear vinyl tubing.  The Zalman labeled tubing is made of a soft durometer plastic, which makes it easy to work with and grips fittings extremely well.  It also has a relatively thick wall (2mm) so it bends easily without kinking.  Connections are made to the back of the Reserator 2 by way of two industry standard CPC quick-disconnect fittings that incorporate internal check valves.  Having check valves is convenient as they block off flow as soon as the connection is broken and keeps any spillage to a minimum.  In high-flow systems, integrated check valves can create significant flow restrictions but in a low-flow system like the Reserator 2, that isn’t as much of a problem and the added convenience is well worth it.

Zalman also includes a bottle of their new ZM-G300 coolant, which contains the non-toxic form of antifreeze (propylene glycol) and corrosion inhibitors.  This formulation is designed to work with various materials including copper, aluminum, and plastic to prevent corrosion.  Another key component in Zalman’s corrosion prevention strategy is gold plating the copper water block.  Gold is virtually inert (under normal conditions) and eliminates the potential for galvanic corrosion that occurs between copper and aluminum in an aqueous solution.