Engineering a Breath of Fresh Air: Achieving Natural Ventilation in Laboratory Buildings
James Sokol, P.E., Affiliated Engineers NW, Inc.
James Sharpe, P.E., LEED AP®, Affiliated Engineers, Inc.
Engineers' efforts typically focus on the economic and environmental entries to the triple bottom line. While natural ventilation (NV) realizes some benefit to these two concerns, it is an increasing priority to clients for its contribution to the final element of the triple bottom line, social advantages, by creating physically comfortable environments integrated with their surroundings. Three recently-completed laboratory buildings in different climatic regions of the United States illustrate the motives, conditions, and challenges of NV.
Successful NV is subject to alignment of practical goals and institutional missions with the absolutes of physical opportunity. Means of isolation to maintain pressure relationships become more varied, integrating with unique combinations of sustainable technologies and strategies.
Committed to public outreach and standing at the hub of the University of Wisconsin's Madison campus, the R&D Magazine 2012 Lab of the Year-winning Wisconsin Institutes of Discovery emphasizes streetscape transparency and access. The open ground floor encourages use by the pedestrian campus community with seating, gathering spaces, garden atria, two cafes, and a restaurant; plentiful glazing suggests greater energy use despite relaxed comfort criteria. A hybrid NV system coordinates automatic operable windows with smoke evacuation fans, while exterior restaurant walls open to the street. Laboratories are controlled with offset flow tracking to ensure negative pressure and the building pressurization system is disabled when windows or walls are open.
Three stories of 10-inch floor slabs in the University of California, Riverside's, School of Medicine Research Building mitigate vibration and allow for mass cooling in a climate of hot summer days with cool, dry nights. Where a typical convection stack approach would draw in unfiltered air and create a negative pressure near the biosafety level (BSL)-3 suite, a reverse concept provides a supply fan with filtration for nighttime purge. Ceiling fans enhance day cooling and room dampers can be opened by occupants; mechanical cooling of office areas is nearly eliminated in this R&D Magazine 2012 Lab of the Year honoree for exemplary sustainable design.
The narrow floorplates in the University of Washington's Molecular Engineering and Sciences Building, common for maximizing daylight, also facilitate NV. Close adjacency of office spaces to laboratories, however, raised concerns of pressure fluctuations driving laboratories into positive pressure. While Seattle's climate is similar to the standard reference point for NV design (Germany), an integration of means (nighttime flush pre-cooling, ceiling fans, and phase change energy storage materials) supplement NV in providing sufficient comfort levels year round. Constant pressure offset is maintained with tight façades and seals on doors into the laboratory space.
Biographies:
James Sokol has 30 years of mechanical engineering, project management, and construction management experience. He has been involved in all phases of project development, including master planning, conceptual design, cost estimate and construction document development, scheduling, and construction supervision. As a strong communicator and project leader, Mr. Sokol has developed innovative communication tools and techniques to help educate building owners and decision makers about complex technical content related to building design and costs, the modern use of energy, and sustainability issues. For Affiliated Engineers NW, Inc., Mr. Sokol has served as the principal-in-charge and project manager for a wide variety of projects for research laboratories and healthcare facilities. He recently led the MEP design for the UC Berkeley Li Ka Shing Center for Biomedical and Health Sciences, which is targeting LEED® Gold certification and features several sustainable design elements.
James N. Sharpe has served as the principal-in-charge and project manager at Affiliated Engineers, Inc., since 1980 on technically complex research, education, and healthcare facilities, including the University of California, Riverside's, School of Medicine Research Building, a R&D Magazine 2012 Lab of the Year honoree for exemplary sustainable design. Mr. Sharpe's background includes facility planning, programming, design, and research experience with mechanical and electrical systems. His specialized experience includes complex building systems, sustainable design, energy management controls, central utility plants, and utility distribution, as applied to biotechnology and academic research laboratories, vivaria, cancer centers, and acute care hospitals. Mr. Sharpe has been a presenter at Labs21 Annual Conferences, the International Facility Management Association Laboratory Construction and Renovation Conference, LabWize Best Practices for Laboratory Design, Tradeline, and BIO Lab Planning.