Daylighting (architecture)
Daylighting is the practice of placing windows, skylights, other openings, and reflective surfaces so that direct or indirect sunlight can provide effective internal lighting.
Particular attention is given to daylighting while designing a building when the aim is to maximize visual comfort or to reduce energy use.
Energy savings can be achieved from the reduced use of artificial (electric) lighting or from passive solar heating.
Their vertical orientation means that they selectively admit sunlight and diffuse daylight at different times of the day and year.
Therefore, windows on multiple orientations must usually be combined to produce the right mix of light for the building, depending on the climate and latitude.
[6] View clarity is often influenced by the amount of shading provided by blinds or devices used to protect occupants from harsh daylight (e.g. glare) or for reasons of visual privacy.
Notably, views that are able to provide building inhabitants with content of nature far outweigh the other four Environmental Information Criteria.
Alternatively, clerestories can be used to admit diffuse daylight (from the north in the northern hemisphere) that evenly illuminates a space such as a classroom or office.
[10] Skylights are light transmitting fenestration (products filling openings in a building envelope which also includes windows, doors, etc.
Roof lanterns serve as both an architectural feature and a method of introducing natural light into a space, and are typically wooden or metal structures with a number of glazed glass panels.
As an element of architecture, a laylight is a glazed panel usually set flush with the ceiling for the purpose of admitting natural or artificial light.
[12][13] For example, the Lyme Art Association Gallery utilizes translucent white muslin laylights below its skylights.
The light shelf projects beyond the shadow created by the eave and reflects sunlight upward to illuminate the ceiling.
[30] They were and are used in the upper portions of windows, and some believe that they contributed to the trend from dark, subdivided Victorian interiors to open-plan, light-coloured ones.
[citation needed] Daylight redirecting window film (DRF) is a thin plastic version of the old glass prism tiles.
The tube itself is a passive component consisting of either a simple reflective interior coating or a light conducting fiber optic bundle.
It is frequently capped with a transparent, roof-mounted dome "light collector" and terminated with a diffuser assembly that admits the daylight into interior spaces and distributes the available light energy evenly (or else efficiently if the use of the lit space is reasonably fixed, and the user desired one or more "bright-spots").
The solar array of such off-grid PV system charges a rechargeable battery, which powers a fluorescent or LED lamp during the night.
They are designed with sufficiently large batteries to ensure operation for at least a week and even in the worst situation, they are expected to dim only slightly.
Oak Ridge National Laboratory (ORNL) has developed a new alternative to skylights called hybrid solar lighting.
A version that can withstand windstorms could begin to replace conventional commercial fluorescent lighting systems with improved implementations in 2008 and beyond.
[36] In a well-designed isolated solar gain building with a solarium, sunroom, greenhouse, etc., there is usually significant glass on the equator side.
Drapes can optionally be automated with sensor-based electric motor controls that are aware of room occupancy, daylight, interior temperature, and time of day.
Passive solar buildings with no central air conditioning system need control mechanisms for hourly, daily, and seasonal, temperature-and-daylight variations.
If the temperature is correct, and a room is unoccupied, the drapes can automatically close to reduce heat transfer in either direction.
East/west glass doors and windows should be fully shaded top-to-bottom or a spectrally selective coating can be used to reduce solar gain.
[38] Studies have also shown that light has a direct effect on human health because of the way it influences the circadian rhythms.
[41] Computational simulations can predict daylighting condition of a space much faster and more detailed than hand calculations or scale model testing.
The goal of the calculation is to determine how long an individual can work in a space without requiring electrical lighting, while also providing optimal visual and physical comfort.
For example, office occupants usually prefer to work at daylight below the illuminance threshold since this level avoids potential glare and excessive contrast.
