Daylight is a crucial aspect of our built environments, influencing everything from our mood to the way we perceive colors around us. However, the journey of daylight into our buildings is not straightforward. It undergoes various transformations, significantly influenced by the glazing through which it passes.

It’s common knowledge that windows are more than just structural elements in a building; they’re our primary source of natural light and connection to the outside world. How daylight through windows influences not only our vision but our overall health and well-being. From affecting our sleep patterns to our productivity at work, the quality of light we’re exposed to indoors plays a critical role in our daily lives.

This blog post delves into the fascinating world of daylight transmission through glazing, exploring how different types of glazing can alter our perception of light and colour.

The Color-Changing Journey of Daylight

Daylight is inherently variable, influenced by time, location, and weather. But its interaction with building glazing adds another layer of complexity. Studies show that the spectral power distribution (SPD) of daylight changes based on the glazing’s spectral properties. This means the color and quality of light entering our buildings can vary dramatically based on the type of window glass used.

The Role of Tinted Glazing

The advancement in window technologies, particularly electrochromic glazing, adjusts its tint in response to light exposure and electrical voltage changes, thereby altering the daylight’s spectral power distribution entering the space.
This technology represents more than a mere aesthetic enhancement; it significantly impacts both how we perceive space and our physiological responses to light. Tinted glazing has been a subject of interest in several studies. For instance, experimental research revealed that the tint of glazing significantly affects colour perception. Participants viewing spaces through different tinted glazing noticed marked differences in colours. Similarly, research on the impact of blue, neutral, and bronze glazing on daylight quality showed that bronze glazing increased arousal levels in office workers.

Evaluating Light Quality

Dubois and colleagues investigated visual perception in scaled rooms with different glazing materials under overcast skies. They found that glazing with higher daylight transmittance received more positive ratings for naturalness and pleasantness. In contrast, a study by Liang et al. showed that bronze window glazing led to more errors in achromatic acuity tests than blue or clear glazing. However, people preferred bronze glazing for its warm tint and natural rendering of the environment.

The study by Angelo et al. highlights that even transparent low-energy glazing can cause color distortions. This type of glazing often transmits less red and blue light, leading to muted colors and a more monotonous space. DeForest’s exploration into electrochromic glazing offered a solution with equal transparency across the visible light spectrum, maintaining both daylighting level and aesthetic appeal.

Beyond Visibility: The Non-Visual Effects of Light

Perhaps one of the most intriguing aspect of the topic is its focus on the non-visual effects of light. As we discuss it in our recent paper (M.Nazari, B. Matusiak, O. Stefani, (2023)) Different glazing types (clear vs. smart/electrochromic) affect our circadian rhythms and other neurobehavioral responses. This area of study is crucial, as it links the architectural design of spaces directly to the health and well-being of the occupants.

Colour Perception in Architectural Spaces

In addition light transmitted through different glazing types can influence the color appearance within interior spaces. This finding is particularly relevant for interior designers and architects, as it affects both the aesthetics and functional quality of indoor environments.

Glazing and Visual Comfort

Salamati’s comprehensive study focused on the impact of thermochromic glazing on indoor visual comfort. This study concluded that lower glazing transparency reduces glare risk in workspaces. Thermochromic glazing was especially effective in controlling glare at higher latitudes. Moreover, it was found to have a lower Melanopic ratio, indicating its influence on non-visual effects like alertness and circadian rhythms.

The Future of Glazing and Daylight

The integration of advanced glazing technologies like electrochromic windows is a promising area for enhancing energy efficiency, thermal performance, and visual comfort. For those interested in a deeper dive into these aspects, numerous scholarly sources offer extensive information.

Conclusion

The way daylight interacts with glazing materials in our buildings is a complex but fascinating subject. From color perception to non-visual effects, the type of glazing used can have significant implications for our experience of indoor spaces. As technology advances, we continue to explore ways to harness daylight most effectively, ensuring that our built environments are both visually comfortable and energy-efficient.

this post is a reminder of the intricate relationship between light and life in architectural contexts. we advance in technology and understanding, the way we incorporate light into our living and working spaces can have a profound impact on our health, well-being, and perception of the world around us.