Impact of Active Cooling On High Power Density Fixtures

Abstract

Lighting fixtures are finding a wide range of applications in Roadways, Sports lighting, Architectural lighting, Industries, etc. Lumen requirement for these applications is constantly increasing thereby augmenting the power needed and consequently the heat generation. To suffice these needs, high power density luminaries with lumens output in several thousand are used. Hitherto, thermal management of these luminaires was achieved through passive cooling with the help of heatsinks attached at the back of LEDs. Heatsinks utilized for this high-power density fixtures are relatively large to provide a higher surface area for heat transfer. With the larger heatsinks in the lighting system, the cost associated with packaging, mounting, manufacturing increases significantly. In addition, weight and EPA of these fixtures increases as well which has a negative impact on retrofit applications where existing infrastructure is designed for lighter weight products and replacing with higher weight and EPA product is not an optimal solution. To address these concerns, the present study focuses on utilizing an active cooling method with multiple fans placed in parallel to reduce the system size and weight. Several parameters such as fan speed, number of fins, fin height, input power, are varied to evaluate LED temperatures. Comparison is made with various design configurations and optimized design obtained through analysis is used for the final product development. Overall reduction in the weight and cost associated is then discussed in details in the summary.