Development of Plant Production System using Mirror Duct (Part III) : The lighting technique and the effect of energy saving by the Mirror Duct

A Mirror Duct is made from the aluminum that has high reflectivity, and can conduct natural daylight into indoors efficiently. The purpose of this study is to reduce power consumption of artificial lighting using the Mirror Duct at plant factory. In this part, the lighting effect of the Mirror Duct system used some reflection mirror was confirmed by the measurement at the laboratory that assumed the Mirror Duct use-type plant factory. Nonimaging Fresnel lens were designed and manufactured for improving the lighting efficiency in high solar altitude season. And a simulation, which analyzes advantages of side lighting from east and west wall using high reflection material, was performed to improve lighting. Based on the results of measurement and simulation, the Mirror Duct can save 20% of power for artificial lighting at plant factory. On the other hand, it is important to save power for artificial lighting at office building and residence. So in this part, energy cut effect by introducing the Mirror Duct into an office building was checked.