Technical FeaTure During the 2008 renovation, ASHRAE switched from a 50/50 mix of private offices and cubicles to 95% cubicles in an open office layout. Minimizing the number of perimeter offices and using glass-walled cubicles maximizes the daylight outdoor views entering the space. Lighting Interior lighting power density is 19% lower than ASHRAE/IESNA Standard 90.1-2004. Photocells, occupancy sensors, and occupancy schedule are used to control lighting use. A change-out to LED lights in some locations also is being considered as an additional energy savings improvement. Lessons Learned We have learned that on/off light ballasts are not suitable for daylighting and that dimmable ballasts are required due to scattered cloud conditions. Adjustments to the photocell hysteresis were not sufficient to eliminate complaints from staff. We also learned that a single controller in a first floor panel controls all the lighting breakers for the building www.info.hotims.com/49803-27 24 ASHRAE JouRnAl ashrae.org Apri l 2014