Development of architectural natural daylight lens using non-imaging optical method

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K18916
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Architecture, Building engineering, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Kobayashi Hikaru 東北大学, 工学研究科, 准教授 (90709734)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: 採光装置 / 非結像工学 / 透明ルーバー

Outline of Final Research Achievements

In this research, we developed a transparent stational daylighting louver installed on the window. In order to respond to a solar trajectory with a stational louver, the cross-section was designed using a non-imaging optic method, and it is possible to illuminate indoors by refraction and total reflection. By using a transparent body as the daylighting louver, we have realized a device that is more compact and easier to maintain than the louver with a curved metal mirror. The daylighting performance of the louver was confirmed by experiments using test pieces using clear acrylic resin and optical simulation. The daylighting device distributes sunlight to the ceiling and reflects the light from the ceiling to illuminate the desk surface. Even at noon in the summer when the solar altitude is high, and it is difficult to take daylight, an illuminance of several hundred lux is expected at a depth of 8m.

Free Research Field

建築環境工学

Academic Significance and Societal Importance of the Research Achievements

地球温暖化問題を背景とした建築物における省エネルギーの推進は急務であり、建築物に適用可能な自然エネルギー利用技術が求められている。太陽光は全ての建物で得られる自然エネルギーであり、昼光照明は昼間の照明用電力を軽減するとともに、快適性や知的生産性の向上に寄与することが期待できる。また、自然採光によって災害時などに最低限の照度を建築空間に確保するなどの目的にも利用できる。