Skylight / July 11, 2018 / Nicolas Charlebois
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.
It is recommended that the skylight size should never be more than five percent of the floor area in rooms with many windows and not more than fifteen percent of the rooms total floor area for spaces with very few windows. Skylights on north-facing roofs provide cool illumination while east-facing roofs provide maximum light and heat in the morning. West-facing skylights provide afternoon sunlight and heat. South-facing skylights provide more passive solar heat than any other location. Skylights are an excellent way to bring more natural light into your home. Just one skylight can dramatically transform your room by adding 30% more natural light than a window. This helps you save energy and makes your home warmer during the winter.
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.