Nautilus500 External Cooling Unit
The Nautilus500 external cooling unit is of simple design and doesn’t include any flashy digital displays or colorful LED lighting effects. Looking at the unit from the front, you can see the top mounted cooling fan, reservoir fill port and liquid level indicator.
The external cooling unit sits up on four legs, which gives approximately ¾’ clearance underneath for airflow to the radiator.
Looking at the unit from the back shows the various service connections and the fan speed switch.
The 4-pin power cable connector is located in the middle, to the left of the two female quick-disconnect fittings. Note: just because the two fittings are labeled Out and IN, doesn’t mean the tubes have to be connected in any particular order (the waterblock flows either way). The two position rocker switch is used to manually adjust the radiator fan speed — High or Low.
A look at the bottom shows the exposed radiator and four rubber feet.
Inside the black plastic enclosure are a pump, reservoir, radiator and cooling fan. The wiring is basic and does not include any temperature control or display circuits like the HydroCool200 had.
Pump
The pump used in the Nautilus500 is the latest version of the Delphi DC pump (DDC) co-developed and marketed in North America by Laing. It is very similar to the DDC used in the Corsair COOL kit but the electronics have been beefed up for even more reliable operation.
The DDC is based on the OEM Apple G5 2.5 GHz liquid cooling system pump. It was specifically designed to provide high reliability, above average head and compatibility with systems incorporating 3/8′ ID tubing. The DDC operates on 12 VDC and is an inline pump, which means it is not designed to be submerged in a reservoir and must not be run dry.
You can read my review of the Laing DDC pump here: DDC 12V Pump review
DDC – Key Features and Specifications
- Small footprint: 2.4 x 2.4 x 1.5′
- 50,000 hours MTBF* (equivalent to 5 year lifetime)
- Convenient 12 VDC operation (plugs into PC power supply)
- Superior real world performance (high pressure characteristics)
- Quiet operation (24 to 26 dBA)
- Maintenance free operation (when used with DI water and biocide)
- Operating voltage range: 8 to 13.2 VDC
- Nominal power (@ 12V): 18 W
- Nominal speed: (@ 12V) 3,600 RPM
- Nominal head (@ 12V): 13.05′ (5.7 PSI)
- Nominal flow (@ 12V): ~92 GPH (350 LPH)
- Connection size: 3/8′ OD barb (10mm)
- Maximum working pressure: 22 PSI (1.5 Bar)
- Operating temperature range: Up to 140°F (60°C)
- Weight: 7.3 oz (207 g)
- Noise (quiet room): 24~26 dBA @ 2′
- Motor type: Electronically commutated, brushless DC, spherical
- Pump MTBF*: 50,000 Hours
*Note: The 50,000 hr MTBF rating is based on Laing’s performance claims for their brushless DC motor with a lifetime in excess of 50,000 hours when operated at 12V.
The Laing DDC pump uses a unique spherical rotor, which contains a small but very strong, two-pole permanent magnet encased in a stainless steel shell. The spherical rotor/impeller sits on top of a ceramic ball and is held in place and by the magnetic attraction between the rotor magnet and stator poles. The rotor/impeller is the only moving part in the pump and since there is no rotating motor shaft there is no shaft seal to potentially leak. The only seal used in the pump is a large O-ring that seals the end casing to the main pump body. The integral closed style impeller contains 9 curved blades, which are enclosed for greater pumping efficiency.
Reservoir
The Nautilus500 incorporates a molded polypropylene reservoir that is closely attached to the pump suction.
The translucent plastic allows the liquid level to be observed thru the slot in the front of the Nautilus500 housing. A fill port is located on top of the unit and is fitted with a large threaded cap that seals with an O-ring.
Radiator
The radiator used in the Nautilus500 is double-pass, flat tube type with a large finned surface area. It measures 120 x 125 x 20mm thick and 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 additive, which is a pet-safe formulation of automotive antifreeze (propylene glycol instead of ethylene glycol). This additive is required for its corrosion inhibiting properties and also contains a biocide.
Corsair uses short sections of Coolsleeves on the internal tubing to keep them from kinking or collapsing in areas with tight bends.
Cooling Fan
The fan used in the Nautilus500 is a medium-low speed 120mm unit (Vette A1225L12D).
120mm Cooling Fan Specifications (High Speed):
Voltage: 12 VDC
Current: 0.3A
Speed: 1,800 RPM
Airflow: 74.4 CFM
Pressure: 3.2mm
The fan pulls air in thru the radiator and blows it out the top of the enclosure. As mentioned before, there is a two-position switch on the back side of the external cooling unit that sets the fan to High (1,800 RPM) or Low (1,200 RPM) speed. High speed offers better performance but with more noise.
