Skylight / July 11, 2018 / Nicolas Charlebois
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.
A skylight is like a window which has been placed in your roof. It has a frame specially designed to withstand rain and prevent leakage from rain and snow. To maximize a skylights use of natural light to illuminate a room or its passive solar heating potential you will want to take into consideration how a skylight is positioned. Facing north your skylight will provide fairly constant illumination but will not provide a lot of heat. Facing east it will provide the maximum amount of light and solar heat gain in the morning. Facing west your skylight provides afternoon sunlight as well as heat gain. A skylight facing south provides the greatest potential for winter passive solar heat gain than any other location but will often allow unwanted heat gain in the summer.
Before installing a skylight in your home you need to carefully evaluate what type of skylight will work best for you considering your specific requirements and how to install it in a way that it improves your homes energy efficiency. Its a sensible idea to evaluate the energy performance ratings of skylights based on the climate that you live in and the architectural design of your home. In the U.S. you can find labeled energy-efficient skylights which tell you the minimum energy performance rating criteria by climate. The physical dimensions of the skylight also greatly affect the lux level and temperature of the space it is being used for.