Radical Fan Energy Reduction and Update on Zero Reheat in Laboratories
Peter Rumsey, Integral Group | Rumsey Engineers
John Weale, Integral Group | Rumsey Engineers
Typically, half of the energy used in laboratories is fan energy required for ventilation. The excessive fan power and reheat costs associated with high volume airflow systems are magnified by the 24 hours-a-day, 356 days-a-year ventilation operation. To mitigate these costs, low-pressure-drop design as presented in the Labs21 Workshop is only half the story.
This session will review the key concepts and the top design strategies for reducing fan energy in laboratories, including: low-pressure-drop design, optimized ventilation rates, unoccupied and night turndown, active sensing systems, and close-coupled cooling that reduces the need for excessive outside cooling. Together, these strategies have resulted in installations where fan energy is reduced by up to 75 percent. These design approaches are also explored as providing design paths to the zero-reheat laboratory.
Standard reheat systems offer poor efficiency in laboratories where internal loads tend to vary widely between zones, making the standard supply air reset approach ineffective in controlling reheat energy waste. Reheat can be eliminated through the application of a number of technologies also used to minimize fan energy, ranging from very mature (such as optimized fancoils) to evolving (such as chilled beams). A recurring design feature is the decoupling of cooling loads from ventilation to reduce fan energy and eliminate reheat.
This session will review the key efficiency strategies and technologies for both new construction and retrofits. Case studies of successful installations will also be presented, including the Center for Science and Mathematics at California Polytechnic State University, San Luis Obispo, California, and the Linde + Robinson Lab for Global Environmental Science at California Institute of Technology.
Biographies:
Peter Rumsey, a national leader in the design of low-energy buildings, is the founder and managing director of Oakland, California-based Integral Group | Rumsey Engineers, the first engineering firm in the U.S. to achieve seven LEED® Platinum projects. He has designed mechanical systems for data centers, cleanrooms, and laboratories that are among the most energy-efficient in the United States. His firm's projects have received many local and national awards from prominent industry organizations, including the Association of Energy Engineers and the American Institute of Architects. He is a registered professional engineer in 10 states, a certified energy manager, a senior fellow of the Rocky Mountain Institute, and an ASHRAE Fellow. He is a graduate of the University of California, Berkeley's mechanical engineering program and is a frequent lecturer at industry events, conferences, and colleges and universities, including the University of California, Berkeley and Stanford University. The focus of Mr. Rumsey's career has been transforming the building industry by designing affordable and dramatically energy-efficient buildings.
John Weale joined Rumsey Engineers in 1999. His work includes extensive design and modeling of efficient mechanical systems for critical environments, including data centers, laboratories, and cleanrooms. He also has considerable experience with many other buildings and complex chilled water plants.
A sample of Mr. Weale's past work includes the design of data centers and laboratories, design of efficient school buildings, and the consultation on the mechanical design of a green brewery building. In the high-performance arena, Mr. Weale's work has included the design of two high-efficiency pressurized plenum cleanroom bays, design of a cooling tower expansion for free cooling, a manufacturing building with extensive exhaust and pressurization control requirements, numerous energy audits and a modular 600 to 3,000 ton central plant utilizing absorption (waste heat driven) and electrical chillers. Cleanroom energy studies have included the measurement, critique, and retrofit payback analysis of the central plant and make-up air system of class 10, 100, and 1,000 cleanroom facilities. Other areas of work have included optimizing exhaust air energy recovery techniques (run around coils, flat plate heat exchangers, enthalpy wheels, and heat pipes), efficient fan systems and controls commissioning. Mr. Weale presented a paper commissioned by Lawrence Berkeley National Laboratories on low pressure drop, low energy use laboratory air handling systems at the Labs21 2002 Annual Conference. Another of Mr. Weale's projects, an upgrade to the Oakland Museum HVAC system to reduce energy use and improve space control, won an award from ASHRAE for technology innovation. Mr. Weale is a graduate of the University of Washington with a Bachelor of Science and a Master of Science in mechanical engineering with an emphasis on energy systems.