Although internal light shelves are more accessible and easier to maintain than external light shelves,they have lower daylighting efficiency than their external counterparts.Past studies on internal light shelves hav...Although internal light shelves are more accessible and easier to maintain than external light shelves,they have lower daylighting efficiency than their external counterparts.Past studies on internal light shelves have primarily focused on fixed room and window sizes rather than identifying them as factors that negatively impact the performance of the light shelves.This study assumes that the room ceiling height is a key factor affecting the daylighting performance of internal light shelves.It evaluates the performance of both internal and external light shelves under various ceiling heights to collect basic data for improving the daylighting performance of internal light shelves.The lighting simulation software Radiance was used to analyze the daylighting performance of these light shelves.The main findings are as follows:(1)In summer and midseason,internal light shelves should be installed in rooms with a ceiling height of at least 4.5 m to achieve a daylighting performance comparable to external light shelves.(2)In summer and midseason,internal light shelves enhance indoor uniformity ratios more than external light shelves;however,incorporating additional shading devices to achieve a comfortable visual environment with an indoor uniformity ratio of 0.3 or less is necessary.(3)Light shelves are not recommended in winter,because they do not contribute to a comfortable indoor lighting environment or energy savings for heating.Removable or detachable light shelves are advantageous;thus,internal light shelves are effective because they are relatively easy to remove and install.This study is significant,as it evaluates the effectiveness and applicability of internal light shelves based on varying ceiling heights.However,it did not consider other variables related to light shelves,indicating that further research is needed to dive into these aspects.展开更多
基金funded by the Korean government(MSITRS-2023-00208303)supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.RS-2024-00441860).
文摘Although internal light shelves are more accessible and easier to maintain than external light shelves,they have lower daylighting efficiency than their external counterparts.Past studies on internal light shelves have primarily focused on fixed room and window sizes rather than identifying them as factors that negatively impact the performance of the light shelves.This study assumes that the room ceiling height is a key factor affecting the daylighting performance of internal light shelves.It evaluates the performance of both internal and external light shelves under various ceiling heights to collect basic data for improving the daylighting performance of internal light shelves.The lighting simulation software Radiance was used to analyze the daylighting performance of these light shelves.The main findings are as follows:(1)In summer and midseason,internal light shelves should be installed in rooms with a ceiling height of at least 4.5 m to achieve a daylighting performance comparable to external light shelves.(2)In summer and midseason,internal light shelves enhance indoor uniformity ratios more than external light shelves;however,incorporating additional shading devices to achieve a comfortable visual environment with an indoor uniformity ratio of 0.3 or less is necessary.(3)Light shelves are not recommended in winter,because they do not contribute to a comfortable indoor lighting environment or energy savings for heating.Removable or detachable light shelves are advantageous;thus,internal light shelves are effective because they are relatively easy to remove and install.This study is significant,as it evaluates the effectiveness and applicability of internal light shelves based on varying ceiling heights.However,it did not consider other variables related to light shelves,indicating that further research is needed to dive into these aspects.
