Methods
I studied the lighting levels in the 6th floor studio of Wurster Hall, along
a cross-section perpendicular to and starting approximately in the center of the
South-facing windows, and extending to the center of the hallway. From the
center of the hallway and from each of four work stations which face toward the
window, I measured the luminance of various surfaces from the perspective of
someone at those stations.
To measure illumination, I used a Luminance Meter, which measures illumination in candelas per meter squared. This device is held like a hand gun and can be aimed at a small region of interest by looking from the back side through a little telescope inside its body. When you pull the trigger, it begins displaying illumination measurements. I found that a dark corner might be measured at about 2 candelas per meters squared, a white page on a desk can range from 15 to 700, while the bright sky can register around 11000.
I measured the luminance of surfaces such as an open notebook page on the desk, the desk top, the window, the shading shelves, the window sills, the wall surface between two windows, the partition walls, the far left wall of the room, the floor in front of the window, and the front of the desk seen from the station behind and facing that desk.
My measurements from the first few days were a bit scattered and
disorganized, as I sought to figure out which were meaningful. I was a bit disappointed with my data set.
However,
after seeing the presentations on daylight penetration and on occupants' control of
pull-down shades, and later that night discussing these and my projects with a
friend, I was re-inspired. I came in early the next day and took a
consistent set of eight measurements from the perspective of each work station
along the cross-section, and from the center of the main hallway. These
measurements were taken at distances of 4, 9, 17, 23, and 36 feet from the
window. I took duplicated measurements from a simulated desk
position in the aisle for those stations which are behind a partition wall, to
correct for the partition's shading effects which were probably not in the
architects' original design. In addition, from the center of the hallway,
in the center of the building along my cross-section, I took all the same
measurements except those for the book, desk, and window sill: the first two
were omitted because I didn't expect any one to be working in the middle of the
main hallway; the latter because the sill was too small from back there to get
an accurate reading, without light from the adjacent window spilling in.
Every two hours that day, from 10:15 through 16:15, I returned to repeat this
set of about 8 measurements for each of 7 positions, for a total of 49
measurements every two hours.
I then input all these measurements into an Excel spreadsheet. Based on the view contexts discussed in the Introduction, I determined meaningful pairs of measurements for which I would determine illumination ratios. I then compared these ratios to the maximum recommended values for each of the view contexts to determine which surface pairs would be considered to have glare. Finally, I reasoned which of these glary data sets were the responsibility of the architect, and which were the responsibility of the buildings occupants, as well as what might be done to fix the problem.