Dictionary
Skylight
Skylights are horizontal windows or domes placed at the roof of buildings, often used for daylighting. White translucent acrylic is a 'Lambertian Diffuser' meaning transmitted light is perfectly diffused and distributed evenly over affected areas. This means, among other advantages, that light source quality standards are measured relative to white acrylic transmission. White acrylic domes provide even light distribution throughout the day. Skylights admit more light per unit area than windows, and distribute it more evenly over a space.
Construction of a DIY skylight
The optimum number of skylights (usually quantified as "effective aperture") varies according to climate, latitude, and the characteristics of the skylight, but is usually 4-8% of floor area. The thermal performance of skylights is affected by stratification, i.e. the tendency of warm air to collect in the skylight wells, which in cool climates increases the rate of heat loss.[citation needed] During warm seasons, skylights with transparent glazings will cause internal heat problems, which is best treated by placing white translucent acrylic over or under the transparent skylight glazing.
Skylights can also double for natural ventilation systems
The amount of light inefficient transparent glazing skylights deliver peaks around midday, when the additional light and heat it provides is least needed. Some skylight designs use domed or pyramidal shapes along with prismatic or other light-redirecting glazings to attempt to validate 'daylighting expert' value. Like automated controls, attempts to achieve more value through expensive additional systems rarely, if ever, validate 'daylighting expert' worth.