Page 39 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 7 DPR CONSTRUCTION OFFICE BUILDING
formation, DPR pushed to complete the commissioning of the building systems and discussed the impact on building operation of occupant behavior with all the staff. With attention to these issues, the subsequent measurements showed an improvement in performance.
One of the operation changes made during the first few months of occupancy was to schedule the HVAC system so that no air conditioning is cycled on during the cleaning period in the eve- ning, when no other activities are scheduled. This eliminated a bump in energy use that was not required for the cleaning staff.
Post Occupancy: Lighting
Daylighting the open office area with the tubular skylights combined with low-level LED light fixtures appears to provide a good level of comfortable, glare-free light, especially for occupants engaged in work on computer screens. (This issue is discussed again in Case Study No. 9, the Speculative Office Building at 435 Indio Way.)
Post Occupancy: On-Site Renewable Energy Systems
While optimizing the design objectives quite well, the flat PV panel arrays require more cleaning than a tilted array. It was also noticed that the east-facing tilted array actually provided a good power boost in the morning, which was useful for the start-up operation.
Obtaining city approvals and avoiding unanticipated delays as the project moved aggressively toward the start of construction became a priority for DPR. City approval for the electrical system was quickly obtained by decoupling the PV system from the electrical permit application. The PV system was submitted later, as an add-on during construction. This also avoided planning approval delays before construction was allowed to begin, which occur occasionally in urban settings due to concerns about the visual impact of PV panel on a roof.
However, when the PV system was added to the project, the utility company, Pacific Gas & Elec- tric Company, notified DPR that the local transformer had to be upsized. The standard lead time for the new transformer was exceedingly long, so a special effort was made to shorten that lead time so that the move-in date could be close to schedule.
Post Occupancy: Occupant Behavior
The case study buildings continue to illustrate the strong influence of occupant behavior on the overall energy use, with low-energy performance improving further with direct involvement and control by motivated occupants. The energy dashboard (photo, right) provides regular informa- tion about building performance and continues to be an effective communication and motiva- tional tool for staff involvement. DPR also provides each staffperson with a “quick reference” guide about each building feature over which they have individual control. The cards of the guide provides basic information on each feature and various control and use options (below).
PHOTO: DREW KELLY Zero Net Energy Case Study Buildings, Volume 2 27