Savings in cooling energy with a thermal management system for LED lighting in office buildings

Abstract

Light-emitting diode (LED) lighting should be considered for lighting efficiency enhancement, however, waste heat from light-emitting diode (LED) lighting increases the internal cooling load during the summer season. In order to solve this problem we propose a thermal management system for light-emitting diode (LED) lighting with a heat exchanger module integrated with the building's heating, ventilation, and air conditioning (HVAC) system to move the lighting's waste heat outdoors. An experiment was carried out to investigate the thermal effects in a test chamber and the heat exchange rate between the heat sink and the duct air. The heat generated by the light-emitting diode (LED) lighting was calculated as 78.1% of light-emitting diode (LED) input power and the heat exchange rate of the lighting heat exchange module was estimated to be between 86.5% and 98.1% according to the light-emitting diode (LED) input power and the flow rate of air passing the heat sink. As a result, the average light-emitting diode (LED) lighting heat contribution rate for internal heat gain was determined as 0.05; this value was used to calculate the heating and cooling energy demand of the office building through an energy simulation program. In the simulation results, the cooling energy demand was reduced by 19.2% compared with the case of conventionally installed light-emitting diode (LED) lighting.