Jason DeGraw: Using data and weatherization to forecast healthy, safe buildings

Long before COVID-19’s rapid transmission led to a worldwide pandemic, Oak Ridge National Laboratory’s Jason DeGraw was performing computer modeling to better understand the impact of virus-laden droplets on indoor air quality by determining how they travel through rooms and throughout buildings.

DeGraw is a thermal-fluid scientist and mechanical engineer who works within the Integrated Building Performance Group and leads ORNL’s participation in the Department of Energy’s Weatherization Program. He uses numerical equations powered by high-performance computing to analyze and solve problems related to the dispersion patterns of biological pathogens and chemical agents.

“Computational fluid dynamics simulations give us an accurate picture of how a contaminant moves and behaves in certain environments,” DeGraw said. “It’s really life-saving information that provides insight into how to improve a building’s resilience and prevent the spread of harmful particles, or at least make it difficult.”

It was DeGraw’s expertise in mathematics and thermal-fluid sciences, honed from years of work in research and academic positions, that ASHRAE, or the American Society of Heating, Refrigerating and Air-Conditioning Engineers, sought out in the early stages of the COVID-19 pandemic.

As an ASHRAE member who had previously chaired the organization’s resilience and security committee, DeGraw was tapped to serve on the Epidemic Task Force in March 2020 and lead development of transportation guidance. The task force produced hundreds of pages of guidance summarized in five core recommendations to reduce transmission of viruses like COVID-19. These recommendations serve as a national guide for industry and building owners and set targets for minimizing outdoor airflow rates. Guidance includes such tactics as using a combination of filters and air cleaners to achieve better levels of performance for air recirculated by heating, ventilation and air-conditioning systems.

“The nation, and really the world, has collectively focused on how to improve indoor air quality in recent months, but I’ve researched this for the bulk of my career,” he said. “It’s certainly a time where my expertise has been in high demand, and I was grateful to be able to contribute to the worldwide response to this pandemic. I’m very proud of our work producing ASHRAE’s Core Recommendations.”

Computer-driven scientific solutions

DeGraw joined ORNL after working in commercial buildings research at the National Renewable Energy Laboratory, where he served on the EnergyPlus development team. EnergyPlus is an open-source whole-building energy simulation program that models both energy consumption — for heating, cooling, plug and process loads, ventilation and lighting — and water use in buildings.

“I wanted to continue my career with ORNL because of its supercomputing capabilities and the Building Technologies Research and Integration Center national user facility,” he said. “Having dedicated computational resources makes a difference in the type of work you can do. Performing research on a supercomputer like Summit has been an interest of mine for a long time because the buildings area of computational fluid dynamics is difficult. You’ve got to determine boundary conditions with occupants — and, as we know, people behave in a random manner. Supercomputing can help make sense of that.”

It was no random coincidence, however, that led DeGraw to ORNL. His great-uncle, also a mechanical engineer, worked in pressure vessel research at the lab from the 1950s until his retirement in the 1990s.

“I still have family in this area, my dad grew up in Tennessee and I have distant relatives working here today,” he said.

DeGraw, who hails from Illinois, followed an engineering path to Pennsylvania State University, where he completed a degree in mathematics before earning his doctorate in mechanical engineering. It was there, while he was working as a graduate research associate and postdoctoral scholar, that he first began developing security metrics for quantifying building-specific risk related to indoor and outdoor chemical and biological events. He developed multizone software utilities and a platform for importing and exporting airflow models to speed up the modeling processing and to identify risks more precisely and efficiently.

“This was in the early 2000s, and it was a scary time because we were experiencing threats such as anthrax. These were grave concerns for our nation and it was critical that we focus on building resilience, specifically equipment like heating and air conditioning, to protect against these potential crises,” DeGraw said.

“Threats may continue, but building technologies innovation continues to evolve,” he added. “Buildings remain our protective shelter and barrier.”

The whole-building approach

DeGraw expects his work leading ORNL’s Weatherization Program to provide another opportunity to impact commercial and residential buildings throughout the nation. ORNL supports DOE’s Weatherization and Intergovernmental Programs Office by working with federal, state and local partners to promote the adoption of energy-efficient and renewable energy technologies and practices.

The program provides a suite of audit tools that are used to determine the best construction suitable for specific dwellings in certain environments, such as hurricane-prone areas, and offers guidance for retrofitting existing structures. DeGraw leads the team of scientists responsible for providing technical support to DOE’s Weatherization Assistance Program, helping grantees in DOE’s network reduce client energy bills and improve the quality of living and comfort for occupants across all neighborhoods, specifically in low-income or disadvantaged areas. He encourages his fellow researchers to take a holistic approach to examining a building to better understand how each part and facet can have a negative or positive impact on its overall performance.

“I take it for granted that I have a comfortable home to return to at the end of the day,” DeGraw said. “My home is a haven for my family; it protects us and provides a high quality of living. Not everyone has that same level of comfort. Weatherization can look specifically at how we can make the standard of living comfortable for everyone in a dwelling.”

DeGraw said that most weatherization efforts will focus on the energy burden or how much a person pays for energy.

“Through technical assistance, we can truly impact people’s lives by reducing the amount spent on energy,” he said. “Almost everyone lives in buildings; our lives are built around them. My job is to continue to work to improve them so that we all have the opportunity to enjoy a safe home, no matter where we live.”

UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.