Page 120 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 11
THE EXPLORATORIUM
Bay-side view of Exploratori- um piers BEFORE renovaton
PHOTO: EHDD ARCHITECTURE
Multitude of Governing Agencies and Stakeholder Groups
In addition to NPS and SHPO, which controlled every aspect of the project related to the historic character of the site and buildings, there were 12 other regulatory agencies and 17 stakeholder groups that had authority for review and approval of design decisions pertaining to many different aspects of the building and site design. This inevitably affected the nature of some ZNE design features.
For example, the Bay Conservation and Development Commission (BCDC) placed many re- quirements and restrictions on the use of San Francisco Bay water that was planned for a water- source heat pump system. Similarly, the Telegraph Hill Neighborhood Association insisted that the solar photovoltaic panels be installed flat to the existing roof to minimize visual impact to the neighborhood, which is located a half-mile away.
Building Program and Hands-On Exhibits
The popular building program guarantees large crowds of visitors daily, totaling over 500,000 people per year. The many hands-on exhibits in the space ordinarily require a high concentration of specific types of lighting as well as equipment that creates an unusual type of plug load for the building. While energy demand is considered in the exhibit design, the principal requirement is the functionality and design of the exhibit itself. Higher than normal lighting and plug loads were therefore expected.
Existing Structures
The piers and warehouse structures had suffered extensive damage in the 1989 earthquake and, in any event, would require structural upgrades for modern seismic safety requirements for a public facility such as this. Combined with the historic restrictions on the visibility of these upgrades, energy-related design features had to be incorporated in unique ways. (See the dis- cussion in Building Envelope below.)
Environmental Constraints
A logical approach to the design of an energy-efficient HVAC system was to take advantage of the presence of unlimited quantities of bay water beneath the piers. The salty water is corrosive, however, and is filled with organic materials including small animals. Tight regulatory control exists over the water quality, temperature and wildlife protection measures. In addition, mainte- nance and operations issues had to be addressed in the design of all aspects of the bay-related building systems. (See the discussion in Heating, Ventilating and Cooling Systems below.)
Design Process and Low Energy Design Strategies
The design team had participated in early studies of the relocation of the Exploratorium facilities, including an evaluation of the pier site when the opportunity arose to obtain a long-term lease for that highly desirable location. When the property was committed to the Exploratorium in 2006, the Board of Directors held a visioning session with its staff and the design team to develop goals and strategies. At this visioning session the design team proposed the idea of designing toward a ZNE-performing facility. The Board and the rest of the participants embraced this proposal as consistent with the institution’s mission, which includes demonstrating to the public technical concepts about their local environment.
Having adopted the goal for ZNE performance, the design team set about developing a set of ZNE design strategies that could be utilized within the many constraints outlined above. It was clear from the beginning that the most serious limitations would be on the building envelope efficiencies and the likely plug loads and electric lighting energy demand, but that very high efficiencies in the design of the heating and cooling systems might be achieved with the ready availability of the bay water.
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Zero Net Energy Case Study Buildings: Volume 2