Koolance EXT-440CU Liquid Cooling System with CPU-380I Water Block Review

Watercooling Kit Deconstructed

EXT-440CU Liquid Cooling System

The EXT-440CU unit consists of an aluminum outer shell protecting the radiator, reservoir, pump, and control PCBs. The back of of the top panel is hinged, held in place with thumbscrews for easy fan and radiator cleaning and maintenance.

The back of the top panel comes off the unit easily, exposing the radiator and fan affixed to it top. The included fan is a variable speed 120mm unit with a standard 3-pin power cable. Koolance includes a wire fan protected in the top panel to protect the fan from debris (and fingers). The fan is oriented to expel air out from the top panel, pulling air from underneath the unit and through the radiator fins.

The included radiator sits directly under the hinged top panel and fan with its inlet and outlet ports facing the back of the unit. The radiator's inlet is fed directly from the pump while its outlet feeds the threaded port on the back right of the unit. Koolance integrated a copper radiator with a fin density of 21 fps (fins per inch), powder coated in black for corrosion and scratch resistance. With such a fine fin density and copper makeup, the radiator is optimized for heat exchange from the coolant to the air with even moderate airflow. The radiator is held in place by brackets attached to the side panels.

The EXT-440CU unit's front panel assembly is held in place via four star screws at each of its corners, black colored to blend with the front panel coloration.

The unit's front panel assembly consists for two plates attached to the frame – the front acrylic plate and the back steel plate. The acrylic plate is solid black to hide the luster of the steel plate underneath with clear windows for the LED display and the reservoir liquid level view. The steel backplate houses the LED display and control PCB. This PCB controls the operation of the display as well as the four user accessible system configuration buttons underneath the display. The backside of the PCB contains a port for the cable connecting it to the main control PCB.

Beneath the unit's front panel assembly are the pump and cylindrical clear acrylic reservoir. The reservoir can hold a good amount of water with its 55mm diameter and 85mm height with a mirrored metal base plate. The reservoir inlet is at the bottom back of the unit, fed from the units threaded inlet port at the back left of the unit. The reservoir outlet feeds directly into the included PMP-300 pump. Koolance placed two blue LEDS on both sides of the reservoir to illuminate the coolant for better liquid level approximation via the front panel window. The base plate reflects the light from the LEDs to better illuminate the coolant. The pump inlet is close to the bottom of the reservoir, but not at the very bottom, allowing water-born debris to settle to the bottom of the reservoir instead of being sucked into the pump. However, this also means that extra coolant is required to meet the elevated level of the pump's inlet port.

With the unit's bottom panel removed, the tubing connections and coolant flow becomes apparent. The coolant enters the unit from the back inlet port on the back left of the unit, goes to the reservoir and pump, and then travels to the radiator inlet, leaving the unit via the threaded port on the back right of the unit (connected to the radiator outlet). Koolance uses 3/8in barbs and clear tubing to connect all the parts, with a 90 degree barb to attach to the radiator inlet. The rear panel PCB and main control PCB can be seen sitting underneath the radiator. Notice that the reservoir and pump are held to the metal crossbar by screws from underneath.

The rear panel PCB sits directly under the rear of the radiator and connects directly to the serial port in the rear panel of the unit. The PCB contains two headers with cables going to the main control PCB, a data cable for temperature and fan speed information transfer and a power cable to power the pump and LCD display.

The main control PCB side directly behind the pump and underneath the front end of the radiator. The PCB contains power and data connection headers for the pump, LCD display, external fans, radiator fan, and thermistors.

CPU-380I CPU Water Block

The CPU-380I water block consists of two main parts, the base block assembly and the aluminum mounting plate. This design allows for use of mounting plates for other socket types, even though the Intel plate is the only one shown. The mounting plate frames the raised portion of the block assembly's top, secured to the block with four hex screws. The screw holes in the mounting plate are countersunk so that the screws are flush with the plates surface. This minimizes compatibility issues with use of large compression fitting with the block.

The block assembly is made up of an upper black-colored acrylic top and a CNC machined copper base plate. The acrylic top houses the inlet and outlet barbs, while the copper base plate is nickel-plated for corrosion and scratch resistance. A rubber grommet sits in a groove along the outer edge of the top to seal it to the base plate.

The acrylic top contains a steel injection plate sitting underneath the inlet port and sealed to the top via rubber grommet. Both the inner and outer rubber grommets sit within groves along the inner and outer edges of the top. The injection plate accelerates the incoming water to increase pressure through the copper plate water channels, spreading the flow along the width of the copper bottom plate. The injection plate is sealed to the inlet channel with a rubber grommet along the outer edge of the inner channel. That way, water is forced to pass through the channels in the copper plate to exit the block through the outer outlet channel. The injection plate itself sits perpendicular to the direction of the copper plate micro-channels.

The copper base contains a series of micro-channels through which the water is forced to flow for optimized heat exchange between the coolant and the copper base plate. The thin-finned nature of the micro-channels increases the surface and contact area for the heat transfer into the coolant flow. The inlet formed by the injection plate site perpendicular to the water channels, forcing water across all channels and out via both sides of the base plate's micro-channels.

The only downside with using a micro-channel design is the increase in flow restriction inherent in its use – pressure builds up on the inlet side because water flow is restricted by the micro-channels. While the water velocity through the micro-channels is increased, the flow rate over the entire system decreases because of the micro-channels.