Envisioning net-zero: The University of California-Merced's Science and Engineering Building II
A photovoltaic structure is a key part of the facility design for the University of California-Merced Science and Engineering Building II. Images courtesy of the authors.
The University of California-Merced's Science and Engineering Building II will be an interdisciplinary facility shared by the schools of natural sciences and engineering. The building is designed to provide research and teaching laboratories, academic offices, meeting rooms, and student lounge areas totaling 102,000 ft2, distributed on three levels and a basement. Sustainable and environmentally sensitive aspects of the building design include minimizing the amount of non-renewable energy and materials consumed, minimizing total carbon footprint, and attaining LEED Gold certification from the U.S. Green Building Council. The building also includes energy production, research, and demonstration integrated i design.
SmithGroup designed the building to respond to Merced's extreme summer temperatures and to the university's desire to produce renewable energy on campus. SmithGroup incorporated passive design strategies to mitigate solar heat gain impacts on the façade and to help minimize cooling loads. Shading systems protect most of the glazed openings in the building. An extensive arcade surrounds the ground-level engineering laboratories, providing both an outdoor shaded connection to the adjacent buildings on campus and opportunities for outdoor academic activities such as robotics experimentation and testing.
The building design incorporates a photovoltaic-clad canopy that covers a public plaza on the ground level. The plaza will provide a shaded exterior gathering space for students, faculty, and staff to engage in educational and recreational activities. Balconies adjacent to meeting rooms provide shaded exterior interactive spaces. The roof reserves an area for future installation of photovoltaic panels. In line with the university's living laboratory goals, an extensive area for faculty and students to conduct renewable energy experimentation and research is located on the roof. A solar system will provide domestic hot water for the building.
UC-Merced has adopted a target of zero net energy and zero net greenhouse gas emissions through 2020 and beyond. This commitment relies on an effort to maximize energy efficiency, implemented through a program that sets energy performance targets for new building designs. The overall goal of the program is to design buildings that consume half the energy and peak demand of other university buildings in California.
The campus also requires buildings to perform 30% better than California Title 24. Specific targets are set in relation to benchmarks that represent the energy performance of existing build stock, developed based on data collected from other University of California and California State University campuses. The benchmarks are differentiated by type of use and corrected for climate. The campus has been phasing in energy performance targets over time. While current designs target 50% of benchmark, the Science and Engineering II design target was 65% of benchmark.
A different view of the PV structure, which covers a public plaza.
During the design phase, SmithGroup created an energy model to evaluate building energy performance against energy performance targets. The model accounted for the performance of all building systems, including laboratory process loads. The building is modeled to perform at 55% of benchmark for annual electricity (22.4 kWh/ft2/yr), 44% of benchmark for peak electricity (2.9 W/ft2), and 41% of benchmark for total source energy (23,000 Btu/ft2/yr). The building is 44.5% better than required by Title 24.
The building HVAC system was designed to eliminate reheat through the use of variable air volume (VAV) terminal heating and cooling in laboratory areas, economizer-based air handling units with intelligent VAV diffusers, and full switchover for heating and cooling. Heat recovery runaround loops temper 100% outside supply air. Careful occupancy sensing, tied to both HVAC and lighting systems, will complement schedule-based building setbacks. In addition, the building utilizes the campus thermal storage chilled water system, which saves energy by producing chilled water at night when the chillers can be more efficiently operated. An energy monitoring and control system will be installed to assess post-occupancy energy performance and enable systems optimization.
The university's energy performance target approach helped drive the sustainability and energy efficiency strategies for the project. The Science and Engineering Building II will be the latest addition to the campus and will help bring the university one step closer towards its 2020 zero net energy goal.
Irene Monis, AIA, LEED AP, is principal at SmithGroup Inc., San Francisco, and John Elliott, CEM, is director of energy and sustainability at the University of California-Merced.