Daylighting Integration Flashcards

What does the term 'sky view factor' (SVF) represent in daylighting analysis?

Answer: The fraction of the unobstructed sky hemisphere visible from a given point

Sky View Factor is the proportion of the sky dome visible from a specific point, accounting for obstructions such as buildings, trees, and overhangs that block sky luminance.

A designer uses prismatic glazing in a daylighting application primarily to:

Answer: Redirect low-angle sunlight upward toward the ceiling for deeper daylight penetration

Prismatic panels use refraction to bend low-angle daylight (especially from the sun near the horizon) upward and deeper into a space, extending the effective daylit zone.

LEED v4 credit 'Daylight' uses which simulation metric as its primary compliance path?

Answer: Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE)

LEED v4 Daylight credit primarily uses sDA (spatial Daylight Autonomy) to verify adequate daylight and ASE to flag potential glare, replacing the older Daylight Factor approach.

In daylighting simulations, the Perez sky model is preferred over the CIE overcast sky model because it:

Answer: Accurately represents both clear and intermediate sky conditions using real meteorological data

The Perez all-weather sky model uses hourly direct normal and diffuse horizontal irradiance data to generate realistic sky luminance distributions for any sky condition.

Which of the following best describes 'glare probability' in the context of daylighting design?

Answer: A metric predicting the likelihood that a source's luminance contrast will cause visual discomfort for occupants

Glare probability metrics (such as Daylight Glare Probability, DGP) estimate the likelihood that luminance contrasts in the visual field will cause discomfort to a typical occupant.

An atrium used for daylighting a multi-story building primarily distributes light through which mechanism?

Answer: Inter-reflected light bouncing off atrium walls to reach surrounding interior spaces

Atria primarily deliver daylight to adjacent spaces through multiple inter-reflections off their walls and floor, so surface reflectances critically affect light penetration depth.

What is the primary disadvantage of using a high Window-to-Wall Ratio (WWR) without additional shading strategies?

Answer: Increased risk of glare and solar heat gain, raising cooling loads

High WWR increases daylight but also admits more direct sun and solar radiation, significantly raising cooling loads and glare risk without complementary shading measures.