The 226 Watt TEC that we are using is going to require a separate power supply. To that end we obtained a Meanwell model S-320-12 industrial power supply. This 320 Watt unit delivers 25 amps at 12 volts, which is perfect for our intended use.

This unit measures 230 X 115 X 50 mm and comes in at 1.15 Kg. With some minor modifications, it can be made to fit in the 5.25" bay opening of a typical midsized case. This power supply comes with no instructions or power cable. If you are a novice please obtain the help and supervision of someone who is knowledgeable (and friendly) before attempting to wire this component. High powered devices can be deadly if used inappropriately.

Once again adversity!  Because of our choice to move forward with dual systems, we now faced with space constraints.  We had to scrap the notion of going with the reclaimed heater core that we intended to use and instead opted for a more compact design.

As you can see, this copper heater core measures 8” x 7-7/8” x 2”, and features 5/8” inlet and outlet fittings.

In order to increase the efficiency of the heater core we went with another extreme solution; this time in the form of the fan we chose which is manufactured by Perma-Cool.

The specs from the manufacturer’s site:

• 8" Diameter 12V Fan
• Mounting Area Req'd: 8" x 10" x 2-1/4"
• Est. CFM:800
• Motor RPM:3000
• AMP Draw:4.5
• Fuse Size: 30 AMP

We have had very good experiences with Custom Sealife (CSL) brand pumps in the past; in fact we used the Velocity Model T3 for our Flagship Case project.  Ultimately our choice for the Hydrothruster’s replacement was the Velocity T2 model which is pictured below:

The specs from the manufacturer’s site:

·    Manufactured with noryl housings and impeller, titanium rotor and separating wall, ceramic bearing     ball, carbon graphite bearing cap and EPDM o-ring

·    Energy efficient (rated at 1.3 amps) and ultra-quiet (less than 30 db).

·    Features “Dry Run Cutout” with thermal switch for added safety.

·    Rated for temperatures to 140° F and line pressures to 50 PSI

·    Back pressure management:

o       780 GPH @ 0’ head

o       700 GPH @ 3’ head

o       240 GPH @24’ head

o       Dimensions: 5”x 6”x 3.5”

For us the most attractive features were the pump's footprint, its efficiency, its ability to handle back pressure, and its low operating noise.

The final step was to modify the pump inlet and outlet to match our ½” water block fittings:

The modified inlet also acts as a reservoir/air trap for the system and assists in priming.   

At this point we will pause to discuss pumps briefly.  More often than not water cooling involves the use of centrifugal pumps. These pumps are driven by an impeller which discharges water that enters its center through a spinning motion. These pumps are readily available at a reasonable cost. They are highly desirable in that they can normally be used for continuous duty. They are also a popular choice among hobbyists including aquarists.

Pumps come in 2 general varieties; the submersible and the in-line. We prefer the in-line variety as they transfer less energy to the water circuit than the submersible pump. We did not say no energy transfer; We said less energy transfer. All things being equal, the in-line pump will yield better system temperatures.

Pump design is an important consideration. Some pumps are designed strictly for fluid circulation, while other pumps are rated for use in high back pressure environments. When considering a pump determine how much resistance needs to be overcome and choose your pump accordingly.

Pumps are inherently inefficient. The greater the inefficiency, the greater the energy transferred to the water circuit.  The use of large pumps (which we have a penchant for) compounds the problem even more. Another point to consider when choosing a pump is your system's ability to dissipate the energy (heat) that your pump will contribute.

Next: Part 4 Continued