An article on skylight shading by Draper’s own Richard Wilson recently appeared in Construction Specifier Magazine. In it, Richard outlines the effectiveness of various shading strategies for skylights.
Below is Richard’s early version of the article, from which the Construction Specifier piece was taken.
Although Skylights are very effective in allowing natural daylight into buildings, this light needs to be properly managed to ensure that spaces aren’t flooded with too much natural daylight, and to mitigate the risk of glare. In addition, the amount of solar radiation that comes through horizontal and inclined glazing is much greater than is the case with vertical facades, and this can cause significant heat gain issues. As a result, it’s important that the shading of skylights is addressed during the design process and that an effective approach is taken.
We have several graphs showing the level of incident solar radiation by elevation for a building in Indianapolis, Indiana. Each graph shows the amount of radiation by time of day and by month.
On the north elevation (Figure 1), there is only background radiation which remains at a broadly consistent level.
The south elevation (Figure 2) is interesting—because of the higher sun angles during the summer, the level of radiation on south-facing glazing is actually greater in the winter months than during the summer ones. The radiation levels on the east and west elevations (Figures 3 and 4) are almost mirror images of each other. The highest levels of incident radiation occur during the summer—in the morning on the east elevation and during the afternoon on the west.
The amount of incident solar radiation, however, is significantly greater on roof glazing for almost all of the year and is noticeably more in the summer months when heat gain is an issue and needs to be dealt with by the HVAC system
Please Note: To continue reading the white paper “Skylight Shading: Challenges and Solutions,” and to download a free PDF copy, click here.