Skylight / July 9, 2018 / Delphine Demers
If the room you intend to illuminate with the skylight has an open ceiling with no attic space above you can install the skylight without needing to construct a light shaft. This is by far the simplest installation and it offers the maximum amount of light and a view of the sky. For ceilings with an attic space above a light shaft must be constructed that connects the skylight to the room. Skylight shafts take one of three forms: Straight in which the shaft drops vertically from the roof to the ceiling and is the same dimension as the skylight itself. This type is the easiest to construct but because of its offset angle relative to the skylight offers the least amount of light.
For example the optimum slope for a south-facing skylight in Columbus Ohio at 40º North latitude is 45º to 55º. Every skylight has a "shaft" which governs how much light is admitted into the room below. If all four sides are flared then the light is spread over a wide area. If your skylight has a shaft with perpendicular sides the light is focused straight below. If your skylights shaft is flared on only one or two sides then the light is sprayed in the flared direction. Ventilation If you wish you can have a skylight which also provides ventilation as well as light to your room. This allows you to release the hot air which collects at your ceiling.
For one thing skylights are positioned in such a way that they are inaccessible unless they are operated by remote. Even in cases of motorized skylights which are easily manipulated there are still some disadvantages that are inherent to skylights that are not present or minimized in windows. Vertical windows lose less heat by convection when compared to skylights. Also since windows are generally protected by overhangs or shrubs they lose less heat by radiation. On the other hand skylights are directly exposed to the sky. Thus they lose more heat by radiation. Proper insulation can reduce this heat loss to a large extent. In the summer season skylights are more exposed to the direct heat of the sun than windows.