A2-4: Assessment and design of innovative building systems and urban infrastructure to mediate impacts on the urban water cycle, heat island, and regional climate
Forrest Meggers, PhD
School of Architecture
Buildings are fundamental components of the urban environment host to many intersections between water, energy and people. Buildings must mediate the basic social demand for physical space and shelter with the basic living demands for water and energy. Our research will help better understand the intersections of these demands through scientific modeling and experimentation to better characterize the nexus between energy and water experienced by society, which is often localized or originated in design and operation of buildings the their urban infrastructure.
Buildings act as a crux for the nexus between water, energy and materials. We research the most critical manifestations of these interactions related to buildings and their supporting urban infrastructure in three overarching themes:
- The urban climate and its relationship to dissipation of water and energy through local urban form, infrastructure, and microclimates
- The energy-water nexus and the role of buildings as the fulcrum connecting mutually dependent water and wastewater demands with energy and water supply
- The design opportunities latent in architecture and the analysis of building systems and infrastructure for more sustainable water and energy solutions
This project will engage with water sustainability through study of energy, buildings, ecology and people, uncovering and bridging the gaps in knowledge that exist between disciplines of fundamental applied science and creative design research. As demonstrated by our thermal imaging research there is much information that can be represented through simple overlay of data onto the form of the city, which can help both scientist address research questions along with designers to conceptualize new solutions to meet challenges of urban water its critical connection to energy in society.
The project will engage with water sustainability through study of energy, buildings, ecology and people, uncovering and bridging the gaps in knowledge that exist between disciplines of fundamental applied science and creative design research. As shown in the figure there is much information that can be represented through simple overlay of data onto the form of the city, which can help both designers and scientist better address challenges of urban water and understand critical relationship between water and energy in society.
We will also consider novel design opportunities for new systems that integrate the benefits of evaporative cooling into the building façade construction itself as already proposed in publications with fellow UWIN collaborators. Novel building simulations of the basic systems as well as the new concepts tools will be connected to data from the wider urban climate models being developed by UWIN colleagues to more broadly characterize the urban setting. With the data developed for a specific building and for consideration of a neighborhood climate we can leverage tools for building façade thermal performance analysis that we have developed to better characterize the heat transfer between people and their surroundings, which will enable a more complete analysis of local thermal stresses on people and connect with research from UWIN colleagues on public health and environmental justice.
Our research also considers the direct relationship of energy and water in urban infrastructure for collection, supply, storm management and wastewater treatment. In conjunction with UWIN colleagues directly on urban water demand and cost we setup methods to evaluate the energy inherent to the various processes in water systems. Our expertise in thermodynamic analysis helps to consider residual heat available in wastewater streams that can be leveraged by utilizing new building heat pump technology. We analyze the energy potentials and how these can incentivize co-benefits in the water management. In a conceptual design project we consider how the decentralized local demand for pumping for the thousands of miles of aqueduct in California creates a local energy demand, which is frequently met by diesel generators. We propose and simulate the use of solar panels not just for power, but also as covers for the channels and evaluate the potential to mitigate evaporative losses from the water surface.
For the climate analysis we will try to gather statistics for percentage of built space using evaporative cooling towers and the typical rate of water consumption. We will also take data on humidity levels around evaporative cooling systems.
The research into the urban climate will include the development and utilization of new models as well as new sensors and field experiments to examine the relationship between climatic conditions and how water and energy dissipate in cities. We compare the role building air conditioning using dry versus wet heat exchange systems.
Dry heat exchangers, such as those used by common window air conditioners and small residential and rooftop units, have lower system efficiencies and are less expensive than larger water driven cooling towers that achieve lower heat rejection and temperatures and higher efficiency by exploiting the wet bulb temperature of the air through evaporative cooling. There are questions that remain to be answered about the local climatic impact on humidity from cooling towers, which we will investigate with distributed sensor platforms measuring humidity variations due to evaporative cooling deployment and the placement of these devices within the geometry of the urban fabric.
We will create building simulation models that calculate the amount of water needed for evaporative cooling towers, and that can also be linked to water demand and usage models or energy efficiency models for building. These can also be adapted for analysis of novel evaporative building design features such as evaporative façade elements.
We will also work on a model of thermal potential from wastewater based on temperature levels appropriate for various building scale and district energy demands for low-grade heat.
- Meggers, F. “Abstracting Energy” in Energy Accounts, Willis, D., Braham, W. W., Muramoto, K., & Barber, D. A. eds. (2016). Energy Accounts: Architectural Representations of Energy, Climate, and the Future. Routledge.
- Meggers, F., Aschwanden, G., Teitelbaum, E., Guo, H., Salazar, L., & Bruelisauer, M. (2016). Urban cooling primary energy reduction potential: System losses caused by microclimates. Sustainable Cities and Society, 27, 315–323. https://doi.org/10.1016/j.scs.2016.08.007
Conference Presentations & Proceedings
- Shim, S., Shin, S., Meggers, F., Bou-Zeid, E., & Stone, H. A. (2016). Controlled evaporative cooling on a superhydrophilic surface: building a green wall. In Bulletin of the American Physical Society (Vol. 61–20). Portland, Oregon. Retrieved from http://meetings.aps.org/Meeting/DFD16/Session/R2.
- Teitelbaum, E., Meggers, F., Scherer, G., Ramamurthy, P., Wang, L., & Bou-Zeid, E. (2015). ECCENTRIC Buildings: Evaporative Cooling in Constructed ENvelopes by Transmission and Retention Inside Casings of Buildings. In 6th International Building Physics Conference, IBPC 2015. Torino, Italy: Elsevier.
- Eric Teitelbaum, Jake Read, & Forrest Meggers. (2016). Spherical Motion Average Radiant Temperature Sensor(SMART Sensor). Presented at the Sustainable Built Environment (SBE) Regional Conference, Zurich. https://doi.org/DOI 10.3218/3774-6_115
- Provisional Patent filed for Spherical Motion Average Radiant Temperature (SMART) Sensor
- Provisional Patent filed for membrane desiccant dehumidification system
Forrest Meggers, PhD – Principal Investigator
School of Architecture and the Andlinger Center for Energy and the Environment
Voice: (609) 258-7831
Email: fmeggers at princeton.edu
In 2013 Dr. Forrest Meggers came to Princeton jointly appointed in the School of Architecture and the new Andlinger Center for Energy and Environment. He was previously in Singapore as Assistant Professor in the Dept. of Architecture at the National University of Singapore where he had traveled initially as a senior researcher and research module coordinator in the Singapore-ETH Centre’s Future Cities Laboratory. He has degrees from Mechanical Engineering (BSE), Environmental Engineering (MS), and Architecture (Dr sc.). His fields of knowledge include building systems design and integration; sustainable systems; renewable energy; optimization of energy systems; exergy analysis; geothermal; seasonal energy storage; low temp hybrid solar; building materials; thermodynamics and heat transfer; and heat pumps. In Singapore he has researched new low exergy building systems for the tropics where as the Low Exergy Module Coordinator he led the research of 5 PhD students and built and transported a novel building laboratory, BubbleZERO from Zurich to Singapore. Previously in Zurich, Switzerland he worked as a Researcher for the Building Systems Group where he received his PhD in the Dept. of Architecture at the ETH Zurich. He also directed research on sustainable systems for the president of the ETH Board. Originally a native of Iowa, Forrest worked on many sustainability projects at the University of Iowa, and worked with Jim Hansen, renowned climatologist at Columbia University and director of NASA GISS, as a Researcher on US Building Stock CO2 emissions. Through all his international and research experiences he always prides himself as an Iowan and a bicycle mechanic.
Current research areas:
- Building systems thinking – linking operation of energy systems and building operation to architectural processes to facilitate more informed design (3 for 2 project, BubbleZERO, IEA EBC Annex 64)
- Radiant heating and cooling systems – Activating surfaces and geometries to add/remove heat from spaces through more effective/comfortable radiant heat transfer (Beyond Shading, Thermoheliodome, Radiant Umbrella)
- Geothermal and heat source/sink optimization – Leveraging thermal gradients in ground and other phenomena to drastically reduce the effort needed to shift heat in and out of buildings (IEA EBC Annex 64, Campus as a Lab)
- Low exergy air conditioning – Designing and studying air systems that minimize temperature gradients and exergy (utilizable energy) needed to condition air, particularly for dehumidification (Desiccant systems, Campus as a Lab)
Marilys Nepomechie, PhD – Co-Investigator
Professor, Associate Dean for Strategic Initiatives
Florida International University
Voice: (305) 348-1887
Hongshan Guo – Graduate Student
Eric Teitelbaum – Graduate Student