New Spinning Heat Sink Design Could Trim Energy Use and Unleash Processing Power

Heat exchanger technology–the cooling machinery that ferries internal heat away from your PC, your computer, your air conditioner, and other appliances–hasn’t changed too terribly much for decades. That’s led to some limiting problems: For instance, more powerful computer chips can’t be run at their full potential because they might overheat. But a new kind of heat sink developed at Sandia National Labs could change all that–and potentially shave seven percent off US electricity consumption.

Conventional heat exchangers have a few primary components: a solid disk or plate that absorbs heat from the source (like a computer’s processor), a bank of metal fins that help ferry the heat away from that disk (the heat sink), and a fan that stirs up the air around the fins to facilitate the outward movement of heat.

This design is pretty standard, and hasn’t changed much in half a century. Moreover, it’s fraught with inefficiencies, most glaring perhaps being the fact that only about five percent of the energy produced by the fan produces a cooling effect. A layer of stagnant air tends to cling to the fins of the heat sink, insulating them to the flow of air around them and retaining heat. Driving the fan at faster rates helps some, but it’s also noisy–making our appliances and computers more obtrusive and annoying.

The Sandia design overcomes this problem by combining the heat sink (the finned surface) and the fan into a single component that sits atop the solid disk, separated from it by a thin cushion of air. This approach improves upon several shorcomings in the conventional design, but primarily it gets right at the problem of that insulating boundary layer of air. By rotating the Air Bearing Heat Exchanger (as it is known) at high RPM, the centrifugal forces reduce that boundary layer by something like a factor of ten.

That allows it to move much more heat more quickly and with less energy expended than a conventional cooler. Which in turn means a computer processor can generate more heat without overheating. Which means it can conduct more operations at higher speeds.

Extrapolate this to to refrigerators, air conditioners, etc. across the entire United States. Jeff Koplow, the Sandia researcher behind the redesigned heat sink, thinks it could cut the national electricity consumption by seven percent while allowing processing power to run free, unrestrained by heat limitations.

The grittier details are here (PDF).

New Scientist