Introduction Over the past few years many people in the electronics industry have become concerned with the increases in heat density at both the chip and module level of packaging. This trend is not new and has been with us since the days of bipolar chips. As can be seen in Figure 1, the heat flux associated with bipolar circuit technologies steadily increased from the … [Read more...]
Using an Equivalent Heat Transfer Coefficient to Model Fins on a Fin
Many readers of ElectronicsCooling are probably familiar with the use of fin efficiency formulas to estimate the thermal resistance of the commonly used parallel plate fin heat sink. Given the heat transfer coefficient, h, acting on a fin and the dimensions of the fin, the thermal resistance of an individual fin is given by: where Af and η are the surface area and … [Read more...]
Server Design Challenges for the High-heat-load Internet Data Center
Introduction Microprocessor and system thermal management are linked to facility cooling: power dissipation and cooling techniques employed at one end of the size scale have cascading impacts at the other extreme (Figure 1). For example, ineffective airflow distribution or insufficient underfloor static pressure in a data center can reduce the supply airflow rate from … [Read more...]
ASHRAE Committee Formed to Establish Thermal Guidelines for Datacom Facilities
Introduction The environment of every data center is complex and unique. Air currents within the data center have hot and cold air streams colliding, cold air exhausting upward from perforated tiles, hot air streams exhausting from tops and the rear of servers and storage racks. Not only are these air circulation patterns extremely complex, they can also be transient in nature … [Read more...]
Estimating Temperatures in an Air-cooled Closed Box Electronics Enclosure
Introduction In the majority of air-cooling applications, openings or vents are provided in the enclosure or box in which the electronic components are housed. The required cooling air is drawn in from outside the box by fans or blowers. In some applications, however, there may be airborne particulates or other substances in the air that would be injurious to the electrical … [Read more...]
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