Explore key concepts, practice flashcards, and test your knowledge — then unlock the full study pack.
The Daylight Factor (DF) is a crucial quantitative metric that evaluates the amount of natural daylight accessible within a building space in relation to external illumination conditions. The DF is calculated using the formula: DF = \frac{E_{inside}}{E_{outside}} \times 100%. Here, E_{inside} represents the indoor illuminance measured in lux, and E_{outside} denotes the outdoor illuminance during overcast skies. This analysis is vital for understanding the effectiveness of daylight penetration indoors. Moreover, illuminance, measured in lux (lm/m²), informs how well surfaces are lit, affecting visibility and comfort. Key factors influencing illuminance include light source intensity and angle.
The concept of Daylight Factor emerged in the early to mid-20th century, significantly influencing architectural design to incorporate natural light. Pioneers such as Louis Kahn and Le Corbusier advocated for daylighting, recognizing its role in energy efficiency and occupant well-being. The CIE (International Commission on Illumination) played a critical role in standardizing sky models in the mid-20th century, promoting sustainable lighting practices in architecture. Understanding these historical contexts and principles behind DF calculations is crucial for architects and planners aiming to optimize indoor lighting conditions.
In architectural practice, evaluating the Daylight Factor (DF) is essential for ensuring adequate daylighting in designs, which leads to lower energy consumption and greater occupant satisfaction. DF is applied not only during the initial design phase but also for retrofitting existing structures that may lack sufficient natural light. Strategies can be employed to enhance daylight access, such as modifying window placements and utilizing shading systems. Understanding these applications of DF helps bridge the gap between theoretical calculations and practical architectural solutions, significantly impacting user experience.
What is the Daylight Factor (DF)?
The Daylight Factor (DF) is a percentage measurement showing the amount of daylight inside compared to outside under overcast skies.
What does the 'E' represent in the DF formula?
'E' signifies illuminance in lux when calculating the Daylight Factor.
What is illuminance?
Illuminance is defined as the amount of light per unit area on a surface, measured in lux (lm/m²).
Click any card to reveal the answer
Q1
What is the primary purpose of the Daylight Factor (DF)?
Q2
Who were key pioneers in the promotion of daylighting?
Q3
What is a significant benefit of assessing DF during building retrofitting?
Upload your own notes, PDF, or lecture to get complete study notes, dozens of flashcards, and a full practice exam like the one above — generated in seconds.
Sign Up Free → No credit card required • 1 free study pack included