Following the retrofit, the newly re-opened skylight provided a significant change in the daytime lighting conditions in the study area of the store. Shown below in Figure 18, the addition of the skylight provides a distinct visual contrast to the surrounding area. As outlined in section 6.2, the intervention involved re-opening two of the four sides of the skylight (keeping the east- and west-facing sides of the skylight covered to block the low-angle early morning and late afternoon sun), as well as adding supplemental diffusing material to prevent glare. In addition, indirect-direct linear fluorescent lighting was added at the perimeter of the skylight to illuminate the interior of the skylight well and provide general illumination at night when no daylight is available, and additional halogen accent lighting was installed to highlight merchandise displays. Figure : Intervention Area With Skylight Opened – Figure : View of Re-Opened Skylight, Showing East- and West-Facing Sides Covered, as Well as Fabric Scrim and Electric Lighting in the Skylight Well The re-opened skylight resulted in significant changes in the physical lighting conditions in the space. Before the intervention, the average illuminance level on the sales floor was 30 As shown below, in , average illuminance levels under, and surrounding the skylight ranged from 55 to 64 foot-candles over the course of the day, during an October 23, 2009 site visit. Values directly under the skylight were as high as 120 foot-candles in some locations. More significantly, the results as seen in Figure 20 show that the daylighting design of the skylight retrofit had succeded in providing high-quality illumination without creating significant contrast between the area directly underneath the skylight versus other parts of the store. The ratio of maximum illumination under the skylight to average of illumination surrounding the skylit area ranges from 1:1.3 to 1:1.75 while the ratio of the illlumination under the skylight to the lowest illumination level surrounding the skylight was between 1:2 to 1:3. Thus the design features installed in the skylight (see Figure 19) succedded in minimizing chances of glare under the skylight as well as minimizing contrast ratios between the skylit area and the surrounding areas while making a visual impact on that area of the store. Note that the illumination measurements both under the skylights and the surrounding areas are a combination of daylight and electric lighting.
Following the retrofit, the newly re-opened skylight provided a significant change in the daytime lighting conditions in the study area of the store. Shown below in Figure 18, the addition of the skylight provides a distinct visual contrast to the surrounding area. As outlined in section 6.2, the intervention involved re-opening two of the four sides of the skylight (keeping the east- and west-facing sides of the skylight covered to block the low-angle early morning and late afternoon sun), as well as adding supplemental diffusing material to prevent glare. In addition, indirect-direct linear fluorescent lighting was added at the perimeter of the skylight to illuminate the interior of the skylight well and provide general illumination at night when no daylight is available, and additional halogen accent lighting was installed to highlight merchandise displays. Figure : Intervention Area – With Skylight Opened Figure : View of Re-Opened Skylight, Showing East- and West-Facing Sides Covered, as Well as Fabric Scrim and Electric Lighting in the Skylight Well The re-opened skylight resulted in significant changes in the physical lighting conditions in the space. Before the intervention, the average illuminance level on the sales floor was 30 As shown below, in , average illuminance levels under, and surrounding the skylight ranged from 55 to 64 foot-candles over the course of the day, during an October 23, 2009 site visit. Values directly under the skylight were as high as 120 foot-candles in some locations. More significantly, the results as seen in Figure 20 show that the daylighting design of the skylight retrofit had succeded in providing high-quality illumination without creating significant contrast between the area directly underneath the skylight versus other parts of the store. The ratio of maximum illumination under the skylight to average of illumination surrounding the skylit area ranges from 1:1.3 to 1:1.75 while the ratio of the illlumination under the skylight to the lowest illumination level surrounding the skylight was between 1:2 to 1:3. Thus the design features installed in the skylight (see Figure 19) succedded in minimizing chances of glare under the skylight as well as minimizing contrast ratios between the skylit area and the surrounding areas while making a visual impact on that area of the store. Note that the illumination measurements both under the skylights and the surrounding areas are a combination of daylight and electric lighting.
CEC-500-2013-006.docx