The Importance of Daylight

Scientifically proven that natural lighting helps people become more happy, calm, healthy, and productive. In addition to this fact, using this sustainable light source in lighting design reduces the need for artificial light and consequently energy consumption.

What Are Daylight and Daylighting?

The light produced by natural light sources such as sun, moon, and stars is called natural light. Daylight, natural light that we use in the illumination of our buildings, is a combination of direct and indirect sunlight during the day and has dynamic properties that change throughout the day and year.

Daylighting is the use of controlled daylight in and outside of the buildings.

Windows, skylights, atriums, solar systems and tubes, redirection, and shading elements, reflecting blinds and daylight control systems are daylighting elements that provide and control natural light during the day for internal illumination.

Why Daylight?

One of the two most important reasons for using daylight is psychological needs and the other is energy-saving requirements.

Daylight improves the overall health and circadian rhythm of building occupants, worker productivity in office buildings, student education performance in schools, and shortens patient recovery times in hospitals.

Having daylight all day long connect people to nature, provide a perfect color rendering and comfortable spaces.

Besides its psychological benefits, daylight is a highly cost-effective abundant natural source that reduces energy consumption in buildings.

Artificial lightings account for up to 50 % of the total electrical energy consumption in commercial buildings. The savings from reduced electric lighting through the use of daylighting systems can directly reduce building cooling energy usage by an additional 10% to 20%. And also an efficient illumination with daylight can reduce energy consumption by more than 80% during daylight hours.

Daylighting Design Criteria

During the design process, the following issues should be considered;

• Climate zone of the building
• Urban planning and building orientation
• Size, forms and location of apertures
• Function and working hours of the building
• Shading for cooling and visual comfort
• Interior design concept with high reflectance surfaces with light colors
• Furniture layout without blocking daylight
• Installing lighting automation systems with daylight sensors and dimming controls
• Features of glasses and translucent materials
• An optimum integration of daylight and artificial light

Goals of Daylighting

• Providing ambient lighting requirements during daytime
• Creating uniform distribution of daylight and avoid uncomfortable brightness ratios
• Full integration with other building systems
• Enabling occupants to perceive the outdoor dynamic nature events during the day
• Creating energy and cost-efficient system with maximum comfort

Reducing energy waste and the dependence on artificial energy sources in lighting is possible only with the right daylight planning and analysis. The architect and lighting designer should focus on sustainable design, including daylight, which is a significant issue in meeting requirements of green building standards.

By properly integrating natural and artificial light, designers can provide lighting that satisfies customers with its value, functionality, comfort, flexibility, and  energy efficiency.

Sources:

https://www.buildinggreen.com/feature/lighting-design-health-and-sustainability-guide-architects
https://www.wbdg.org/resources/daylighting

Lumière naturelle

https://www.lampesdirect.fr/blog/lumiere-artificielle-vs-lumiere-naturelle/
https://www.archlighting.com/projects/daylight-designs_o

Lighting

http://www.solarspot.it/fr/a-propos-de-nous-fr/la-lumiere-du-jour