Some issues in experimental testing and methodologies in the thermal management of telecommunication components, systems and enclosures

In many telecommunications applications, switching/signal processing equipment is continuously increasing in capabilities, and more importantly, heat dissipation. The equipment often must be housed in enclosures that more often than not will be placed outdoors. The housed equipment generates heat that must dissipated while keeping the air temperature inside the cabinets within prescribed limits for optimum performance. However, before any attempt at designing a thermal management system can take place, the designer must know how much heat the equipment dissipates, how to thermally characterize the equipment and how to conduct experimental programs to validate the designs. This paper tries to assess and point out the necessary methodologies commonly used in the experimental characterization and validation of telecommunications subcomponents, components and cabinets. The indispensable use of wind tunnel testing for racks and boards, heat sinks, complete rectifier systems, and overall systems (cabinets) is discussed. The need to benchmark in-house cooling equipment such as air-to-air heat exchangers is also covered.