Date of Award
Liquid Filled Prismatic Louver, Daylight harvesting facade, Thermal harvesting facade, Daylighting, Solar energy harvesting, Sustainable energy building
Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Good daylighting implementation enhances the amount of useful natural light within a space, thereby offsetting the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both simultaneously. The proposed Liquid Filled Prismatic Louver (LFPL) system presented in this M.S. Thesis combines both energy saving strategies, i.e., daylighting and thermal energy harvesting into a single platform.
In this M.S. Thesis, experimental testing was performed for both daylight redirection and thermal energy harvesting performance of a LFPL facade system. The LFPL system was installed in a southwest-facing building façade located in New York City and evaluated for indoor daylight penetration and potential for thermal energy capture and management. Daylight redirection was achieved through the prismatic geometry of louver elements, while thermal energy harvesting was achieved through IR absorption of the fluid volume (e.g., water) within the prisms. Daylighting performance was evaluated by illuminance measurements at key locations within the space, whereas thermal harvesting performance was evaluated through water temperature measurements and thermal imaging analysis of the system during operation. We show that the LFPL system achieved effective daylight redirection to the ceiling which provided greater illuminance values (e.g., 210% increase in average ceiling illuminance) and deeper penetration (e.g., 4 m) in the space as compared to a space without the LFPL system. We also demonstrate the system’s capability to adjust to specific lighting needs within the space through the dynamic rotation of prismatic elements; thus, achieving an 8640% increase on the average concentrated illuminance level of a selected portion of the ceiling which resulted in a 514% increase on the work plane illuminance positioned close to the illuminated ceiling area. Furthermore, we show a reduction of potential heating loads at locations close to the window from the combination of IR absorption in the water volume and the redirection of the incoming solar radiation. For example, up to 20 °F difference was observed on the surface temperature of common office items at the proximity of the window. Finally, we discuss future improvements and research goals for the continuation phase of this project.
Alva, Michael, "Smart Prismatic Louver Technology for Enhanced Daylighting and Management of Thermal Loads in Green Buildings" (2018). CUNY Academic Works.