Skylight, Roof opening covered with translucent or transparent glass or plastic designed to admit daylight. Skylights have found wide application admitting steady, even light in industrial, commercial, and residential buildings, especially those with a northern orientation. Installations range from purely functional daylighting to elaborate aesthetic forms. Flat-roofed buildings may have domed skylights; in others the skylight follows the slope of the roof. Often the skylight, or a portion of it, functions as an operating window to admit air Skylighting types include roof windows, unit skylights, tubular daylighting devices (TDDs), sloped glazing, and custom skylights. Uses include:
• Daylighting elements used to allow direct and/or indirect sunlight, via top lighting.
• Providing a visual connection to the outdoor environment to interior occupants.
• Sustainable building — passive solar heating, and with operable units; ventilation for passive cooling and fresh air exchange.
Fixed unit skylight
A fixed skylight consists of a structural perimeter frame supporting glazing infill (the light-transmitting portion, which is made primarily of glass or plastic). A fixed skylight is non-operable, meaning there is no ventilation.
An operable (venting) unit skylight uses a hinged sash attached to and supported by the frame. When within reach of the occupants, this type is also called a roof window.
A retractable skylight rolls - on a set of tracks - off the frame, so that the interior of the facility is entirely open to the outdoors, i.e., not impeded by a hinged skylight. The terms retractable skylight and retractable roof are often used interchangeably, though skylight implies a degree of transparency. The primary purpose of a sunshade is to control the amount of direct sunlight through your building's windows. There are many different reasons for controlling the amount of sunlight that is admitted into a building. In warm, sunny climates excess solar gain may result in high cooling energy consumption; in cold and temperate climates winter sun entering south-facing windows can positively contribute to passive solar heating; and in nearly all climates controlling and diffusing natural illumination will improve daylighting.
Well-designed sun control and shading devices can dramatically reduce building peak heat gain and cooling requirements and improve the natural lighting quality of building interiors. Depending on the amount and location of fenestration, reductions in annual cooling energy consumption of 5% to 15% have been reported. Sun control and shading devices can also improve user visual comfort by controlling glare and reducing contrast ratios. This often leads to increased satisfaction and productivity. Shading devices offer the opportunity of differentiating one building facade from another. This can provide interest and human scale to an otherwise undistinguished design.