Integration of daylighting and building design for human health and well-being

Lee, Jaewook

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https://hdl.handle.net/2142/108694 Copy

Description

Title

Integration of daylighting and building design for human health and well-being

Author(s)

Lee, Jaewook

Issue Date

2020-07-15

Director of Research (if dissertation) or Advisor (if thesis)

Boubekri, Mohamed

Doctoral Committee Chair(s)

Boubekri, Mohamed

Committee Member(s)

• Liang, Feng
• Yi, Yun Kyu
• Bub, Kristen

Department of Study

Architecture

Discipline

Architecture

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Daylight
• Building Design
• Human Comfort
• Daylighting Metrics

Abstract

Most people spend the majority of the daylight hours at work, at school, or even at home. Daylight is the primary light source, and it is one of the most important factors that allow people to live and enjoy life. Besides, daylight has a positive influence on human health, wellbeing, sleep quality, school and work attendance or absenteeism, performance, and circadian cycles. In general, the intensity of the artificial light inside the office is about 300 lux, and it is very difficult to replace the intensity of natural light (1000-10000 lux) that can entrain people’s circadian rhythm. As a result, we are generally exposed to light levels below what is needed to regulate circadian rhythms inside buildings. Using a diverse sample of office workers, the researcher investigates the independent effects of daylight exposure during the workday on various aspects of sleep and health problems. Also, there is a lack of daylighting metrics that address human health and wellbeing in building design. This lack of daylighting design metrics leaves architects and building designers without any means to directly address building occupants’ health issues, particularly when it comes to the needed daylighting exposure to regulate office workers’ circadian rhythm and sleep quality. Study 1. The purpose of this study is to examine how daylight exposure affects the health and well-being of office workers. Sleep actigraphy data and health and well-being related surveys were set as the main output indicators in this study. Office workers participating in the experiment were largely composed of participants from the United States and South Korea, each divided into those who work in daylight environments and those who do not. A total of 50 participants used Actigraphy to measure sleep and ambient light levels for two weeks. Additional health and well-being indicators were based on the Daylight Survey, the SF-36 for general and mental health, and the PSQI for sleep survey. In addition, a computer simulation was used to generate and compare the annual lighting exposure data within these offices. Actigraphy results show that those working in daylight environments indicate higher exposure to light, greater sleep time, and higher sleep efficiency. The results of the survey also show that the indicators; sleep, health, and daylight exposure of those who work in the daylight environment are better when compared to those who do not. In particular, the Role limitation due to physical problems and Vitality in SF36 and Sleep efficiency and Global PSQI score are validated by our statistical analysis. Our findings indicate that it is important to provide and maintain significant daylight levels at the workplace. In terms of architectural design, orientation, building dimensions, and the size and height of windows should be taken into consideration to optimize or maximize daylight exposure. Study 2. This study investigates the applicability of emerging frameworks for evaluating the effect of daylight through the development of a new daylighting metric for human health and wellbeing in buildings. Procedures based on annual daylight availability modeling are used to draw the mapping and analyze indoor daylight environments in regards to spatial, daily, and seasonal changes. For the assumption of the new daylighting metric, information derives from literature reviews and experimental studies were used to set the two major scenarios of the metric as 1) 400 lux for 5 hours (2K lux·h) in the daytime and 2) 500 lux for 1 hour (0.5K lux·h) in the early morning. Therefore, based on two scenarios, we analyzed how the metrics work in the interior zone of the office building. In this process, visualization techniques are implemented in a parametric computer simulation workflow. Through the visualization results, we evaluated the application of the daylighting metric on the building layout and compared the new daylighting metric for health and wellbeing with conventional existing daylighting metrics. These studies are the first to provide examples (results/evidence) that, in addition to human health and well-being, daylight may also affect better sleep time and efficiency. Given the relationship among the daylight exposure, sleep, and health-related indicators of 50 office workers, these results have important implications that the results can be expressed as a daylighting metric for health and well-being and can be actively utilized in the building design process.

Graduation Semester

2020-08

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/108694

Copyright and License Information

Copyright 2020 Jaewook Lee

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