Sizing your Skylight Properly
What many people do not understand about skylights is that the size of the skylight is very crucial. Too big and you have too much heat gain in the summer and too much heat loss in the winter. On the other hand too small and you do not achieve maximum efficiency or your specific objectives.
The crux of the problem is that there is no standard formula that will calculate the ideal skylight for your situation. There are just too many variables and mitigating factors to allow an easy solution. For example, if your particular tastes, or the home that you currently reside in, resembles the construction typical of that in the 1970’s, with low ceilings and beams and dark paneling—you’re going to need a larger than average skylight for that room because the dark colors and shadows are absorbing light and not reflecting it. On the other hand, if you reside in a home with vaulted ceilings, white or light colored furniture and carpets, then a smaller skylight will probably achieve your goals just fine.
There are, of course, many different factors that affect the light brought into a room besides just choosing the size of your skylight. It is also important to consider if there is the need for a shaft (light tunnel) to go through the attic in order to install the skylight, and that it be positioned and sized appropriately as well. Most skylights require some type of shaft, which are best when they are designed slanted or flared. You’ll also want to consider the direction the skylight will face, (north, south, east, west) the type of paint the shaft will be finished with (flat or hi-gloss) and the option of having some electrical lighting installed within the shaft area for those night time hours. Even the type of glazing you use for the skylight will make a difference in the type of light that you will experience in your room.
All of these factors will make a difference and with proper consideration (here is where experience counts) can ultimately lead to your overall satisfaction with this addition and upgrade to your home or office environment.