Free Convection Heat Transfer from a Totally Enclosed Cabinet Containing Simulated Electronic Equipment

An experimental heat-transfer study was performed to obtain design criteria for totally enclosed electronic equipment. Tests were performed on an experimental cabinet containing nine sources simulating electronic devices, and results were obtained for different distributions of source locations and heat-flux levels. Results indicate that 1) improving exterior wall emissivity from 0.2 to 0.98 drops the temperature for both cabinet wall and internal ambient air by 25°F: 2) the difference between internal ambient-air and cabinet-wall temperatures at a given power level remains nearly constant despite variations in cabinet-wall temperature; and 3) concentrating sources near the cabinet top produces extreme gradients in the local ambient while the air below remains considerably cooler whereas dissipation only in the lower levels produces near isothermal ambient temperatures throughout.