Thermal performance analysis of a novel linear LED housing with inner and outer fins

Abstract

There is an inverse relationship between the junction temperature of the light-emitting diode (LED) and its lifetime therefore, it is significant to operate it at low junction temperature. In this study, three different natural convection linear housing models were developed to cool mid-powered LED arrays, focusing on basic parameters such as fin structure, surface area, and wall thickness in the design of the models and thermal performance has been tested numerically and experimentally. The performance tests were carried out at five different ambient temperatures, 20, 25, 30, 35, and 40 °C. Compared to Model-1 (standard housing without fin) and Model-2 (thin housing with inner fin), the cooling effect of Model-3 (thin housing with inner+outer fin) is remarkably high, and this effect was more evident with the increase in ambient temperature. This impact has been achieved by increasing the surface area of Model-3 by almost 50%, although its mass has decreased more than twice. The maximum junction temperatures of Model-3 were approximately 2 °C lower than Model-1 and 5 °C lower than Model-2 in all experiments, with the presence of fins and the development of geometry. When the maximum allowable temperature rise is 94.68–101.25 °C and the 35 watts dissipated in the package, the average thermal resistances were found to be 1.12–1.38 °C/W. It is thought that these new-generation LED-based linear designs can be used to illuminate the work areas and they can replace compact lamp-based luminaires that work with direct and indirect lighting principles.