Experimental study on PPFD and electricity consumption for Hybrid Louver Lighting System(HLLS) in indoor vertical farms

This study developed a hybrid louver lighting system that combines daylighting using solar energy and LED to solve the problems of high electric consumption and heat load of LED used in vertical farm. This system can control the LED lamp according to the intensity of daylighting that changes in real time to meet the set target PPFD. The louver is composed of transparent vacuum glass and diffuser, and multiple horizontal slats installed air cavity in louver effectively transmit the daylighting to the indoor and distribute the required PPFD. The vent applied to the upper and lower of the louver discharges unnecessary heat generated from the LED lamp to the outdoor in summer and utilizes the required heat indoor in winter. The electric consumption of the hybrid louver lighting system and the indoor temperature due to the heat load were evaluated using a full scale mock-up facility.