Improving Heat Dissipation of Light-Emitting Diode Lighting Fixtures in Plant Factories Using a Heat Pipe and Rectangular Fins

Abstract

This study proposes a novel passive heat dissipation structure that combines a heat pipe with multiple rectangular fins to enhance the cooling performance of Light-Emitting Diode (LED) lighting fixtures used in plant factories. Four configurations were experimentally evaluated: a reference model without additional cooling, model incorporating a thin metal plate above the switched-mode power supply (SMPS), model with a heat pipe–fin structure installed only near the SMPS, and model with heat pipe–fin structures installed at both the SMPS and fixture end. The heat pipe–fin structure effectively reduced the heatsink surface temperature, achieving a maximum decrease of 7.2 °C compared with the reference model. The measurements of thermal resistance confirmed significant improvements, with the dual heat pipe–fin configuration (the SMPS and fixture end) exhibiting a 30.3% reduction relative to the reference model. These results were attributed to the efficient heat transfer by the heat pipe and enhanced convective dissipation through the rectangular fins. The proposed passive heat dissipation approach is simple, cost-effective, and requires no additional power, making it highly suitable for improving the long-term thermal stability, reliability, and energy efficiency of LED lighting fixtures in plant factory applications.