Skylight
From Swikipedia
Introduction
Skylights are horizontal windows or domes placed at the roof of buildings, often used for daylighting. Skylights admit more light per unit area than windows, and distribute it more evenly over a space.
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.
Poorly constructed or installed skylights may have leaking problems and single-paned skylights may weep with condensation. Using skylights with at least two panes and a heat reflecting coating will increase their energy efficiency.
Brief Description
Types of Skylights:
1. Traditional Skylights
Traditional rectangular skylights can provide daylight, views, aesthetics and ventilation. Recent technologies have improved their performance: heat absorbing tints, double and triple insulated glazed panels, low-e coatings. These recent features allow huge improvements relatively to older skylights, reducing or overcoming potential negative impacts.
2. Tubular, Dome and Other Modern Skylights
There is a wide variety of modern non-rectangular skylights, involving a large variety of shapes: pyramidal, dome, circular, oval, diamond, multi-sided, tubular etc.
Sun-tunnel tubular skylights design reduces the daytime overheating and night-time heat loss. They are also typically cheaper and easier to install. However, they cannot provide views and ventilation. Like traditional skylights, tubular skylights aren’t very effective in providing illumination to rooms that aren't directly under the roof or attic. Tubular skylights can only light effectively the top floor of multi-story houses. Also, whenever the installation requires a long tube, the effectiveness of the skylight may decrease significantly. For higher performances, tubular skylights shouldn’t be mounted on shaded areas or non-sunny slopes of the roof.
3. Solar Skylights
The solar skylight, which is a combination of a traditional skylight coupled with silicon solar cells, has entered the marketplace. The idea behind this type of skylight is to harness the sun's energy in order to produce electricity and, using a specially designed fluid-filled pipe, to produce a highly heated liquid that can run a heater or a specialized cooling system driven by heat. The solar skylight has limited availability today but can be bought through certain roofing or building contractors, or from some local utility companies.
Benefits of Skylights:
Skylights allow natural daylight to enter the rooms and this makes the rooms look more spacious, expansive and more beautiful.
The increase in natural light helps decrease the overall energy costs.
Skylights that open up can also provide ventilation in rooms that may not be well ventilated.
References:
http://en.wikipedia.org/wiki/Skylight_(window)#Skylights
http://www.skylightsdirect.com/
