Indoor Visual Comfort: A Review of Factors and Assessments

Abstract

The importance of lighting in architectural design has evolved from influencing the structure of buildings to giving precedence to energy efficiency and, more recently, emphasizing the well-being, health, and comfort of occupants. This necessitates a fresh perspective on examining lighting and its multifaceted impact on indoor spaces. This paper conducts a systematic comprehensive review of published research to explore and identify the diverse factors that affect visual comfort indoors and the assessment methods and techniques to evaluate it. The paper adopts a systematic literature review as a methodology and explores the relevant papers from the past 15 years in the domain of building sciences, architecture, lighting technology, and chronobiology with a focus on visual comfort and luminous environment. It also includes a few data from some older sources to provide a broader perspective on research in the field. The findings demonstrate current knowledge on visual comfort research and should be a valuable resource for architects, engineers, and building designers seeking to create comfortable, healthy, and wellbeing-promoting environments. It concludes that lighting research has progressed to encompass a holistic approach to indoor visual comfort, considering factors like lighting, environment, human elements, and architecture. Objective assessments now employ innovative techniques like computational simulations and HDR imagery, while subjective assessments concentrate on occupant preferences and eye-tracking methods integrating Building Management Systems (BMS) in buildings. The adoption of the Equivalent Melanopic Lux (EML) metric by ISHRAE is a positive development in India's context, but there is a need for more diverse research in various settings and populations. Significantly, more studies are required on visual comfort in educational, residential, and commercial settings, indicating the need for immediate attention to better environments.