Shifting the gold-standard in building cooling: from mechanical to natural

Stanford Energy Research Consortium (SERC)

Background

Globally, increased urbanization is expected to lead to an unsustainable energy demand for cooling, the so-called ‘cold crunch’. The 2018 report of the International Energy Agency on ‘The Future of Cooling’ states that, without action to address energy efficiency,energy demand for space cooling will more than triple by 2050, consuming as much electricity as all of China and India today.Natural ventilation, which uses the natural forces of wind and buoyancy to ventilate and cool a building, can reduce building energy consumption by 10% to 30% and provide a solution for the ‘cold crunch’. Despite the significant potential for energy savings, natural ventilation is not widely adopted. For example, in the colder climate zones of California, where natural ventilation alone could provide adequate cooling, ~50% of homes and apartments and most commercial buildings continue to use mechanical air-conditioning. 

Interviews with designers and policy makers have indicated three implementation challenges. First, to consistently guarantee thermal comfort for occupants and building operators, the natural cooling system should be able to adapt to highly variable weather conditions, requiring careful control of windows and vents. Second, advanced models that can support the design of robust natural ventilation systems for a variety of building types and climates are not readily available for architects, engineers, and developers. Third, there is insufficient understanding and evidence of economic, equity and environmental benefits to support policy that will promote the use of natural ventilation.

Project Goals

Our goal is to design solutions and policies to address these implementation challenges by working closely with three key stakeholders: occupants, building designers, and policy makers. Within the context for this project, we will consider a variety of building and occupant types within California. 

Planned activities

• At the occupant level, our objective is to identify natural ventilation solutions and human-centric control systems that will increase adoption. We will use a mix of qualitative and quantitative methods to uncover the variety of perceptions on cooling and quantify attitudes and trends on how occupants intersect with a building. Depending on the building and occupant type, we will investigate solutions to optimize natural ventilation use by occupants, ranging from message tech to advanced control systems.
• At the designer level, our objective is to identify how our modeling research to support robust design and operational control could be leveraged to increase adoption. We will use a co-development strategy, working together with designers to identify educational needs, such as a learning hub, and technical needs, such as embedding natural ventilation models into existing design software.
• At the policy maker level, our objective is to identify and obtain the data and evidence needed to quantify the economic, equity, and environmental benefits of natural ventilation to society. We will work closely with policy makers at the California Energy Commission to ensure that our efforts will support effective policy towards promoting the use of natural ventilation.  The planned activities will provide a starting point for accomplishing an urgently needed shift towards optimally leveraging natural cooling.

Team Members

To accomplish our goal, we have assembled an interdisciplinary team spanning several key areas: 

Catherine Gorlé
Catherine Gorlé is the Associate Professor of Civil and Environmental Engineering at Stanford University. Her research focuses on the development of predictive flow simulations to support the design of sustainable buildings and cities. Specific topics of interest are the coupling of large- and small-scale models and experiments to quantify uncertainties related to the variability of boundary conditions, the development of uncertainty quantification methods for low-fidelity models using high-fidelity data, and the use of field measurements to validate and improve computational predictions.

Sarah Billington
Sarah Billington is the UPS Foundation Professor at Stanford University. Her group focuses on understanding the impact of building design and materials on human wellbeing, developing design tools to quantify nature experience in buildings, and understanding the role of the built environment in public perceptions of and support for affordable housing. They explore how buildings can include both physical and digital adaptations to improve wellbeing outcomes including new methods of bringing nature and the experience of nature into buildings. The group is interested in how building management systems can be extended beyond providing energy savings, thermal comfort, and security to support and maintain a broader set of human wellbeing outcomes while preserving occupant privacy. Further, they study the impact of built features, including historic structures, on community wellbeing and methods of design for community wellbeing that support the equitable development of affordable and permanent supportive housing

Rishee Jain
Rishee Jain is the Associate Professor in the department of Civil and Environmental Engineering at Stanford University. His research focuses on the development of data-driven and socio-technical solutions to sustainability problems facing the urban built environment. His work lies at the intersection of civil engineering, data analytics and social science. Recently, his research has focused on understanding the socio-spatial dynamics of commercial building energy usage, conducting data-driven benchmarking and sustainability planning of urban buildings and characterizing the coupled dynamics of urban systems using data science and micro-experimentation.

Gabrielle Wong-Parodi
Gabrielle Wong-Parodi is an Assistant Professor in the Department of Earth System Science at Stanford University. She is an interdisciplinary social scientist, theoretically grounded in psychology and decision science, who seeks to understand (1) how people make decisions to address the impacts of climate change, and (2) how robust interventions can empower them to make decisions that serve their lives, communities, and society. Her work focuses on frontline communities who experience the "first and worst" of climate change.

Other Team Members
Dian Gruenich, Precourt Energy Scholar, Stanford University