New design for heat sink could speed up computers

New Scientist : Researchers at Sandia National Laboratories have come up with a new design for the heat exchanger used in home computers, writes Melissae Fellet for New Scientist. Traditional heat exchangers, which haven’t changed much in 40 years, consisted of a heat sink and a fan. Unfortunately, although the fan stirred up the air around the heat sink’s metal fins, a layer of stagnant air clinging to the fins would insulate them like a blanket and reduce the overall cooling effect. Spinning the fan faster helped, but made the computer very noisy. In the new design, the fan is the heat sink. Bands of metal blades rotate above the heat source and are separated from it by a thin cushion of air. Centrifugal forces roil that air to facilitate heat transfer. They also compress the layer of stagnant air against the blades, reducing its insulating effect. The new design should not only reduce fan noise and use less energy but also speed up the machine.