Nomenclature Q Heat load (W) COP Coefficient of Performance I Electrical current (Amps) T Temperature (°C) R Electrical resistance (Ohms) Z TE Figure of Merit (1/K) where Z = α2 / (ρ λ) Greek Letters Δ Change in value θ Thermal resistance (°C/W) ρ Electrical resistivity (Ohm-cm) α Seebeck coefficient (V/K) λ Thermal conductivity … [Read more...]
Liquid Cooling is Back
Introduction IBM announced its return to water cooling on April 19, 2005 with the introduction of a water cooled heat exchanger mounted to the back cover of a 19 inch rack. This is the first of the major datacom equipment manufacturers to employ water cooling for a rack of CMOS processors, using a cooling distribution unit supplying the water and rejecting the heat load to … [Read more...]
Review of Low Profile Cold Plate Technology for High Density Servers
Introduction Water cooling of computers was introduced more than twenty years ago, but had disappeared from the mainstream by the mid 1990s. The conversion of chip technology from bipolar to CMOS (complementary metal oxide semiconductor) was the main reason. As chip powers continue to increase, water cooling appears likely to become mainstream again. In the current market, the … [Read more...]
Communication Network Power Efficiency Assessment, Limitations and Directions
Introduction Despite the slowdown in the communication industry, Internet traffic continues to grow rapidly, fueled by the explosion in data communications, mobile Internet, e-commerce, content rich applications, and multi-media services. Internet traffic has increased by approximately 80% yearly in each of the last three years, and will continue to grow at 60 - 80% annually … [Read more...]
Cooling Technology Options, Part 2
(Editor's Note: Part 1 of this article appeared in the August 2003 issue of ElectronicsCooling. Illustration references in this part begin with Figure 5.) Cooling electronic systems is one of the major focal points of the design process and the key to a successful product launch. Many options to attain successful operation are available, ranging from passive cooling to … [Read more...]
