July marked the 14th month in a row of record high global temperatures, and as the month ended, the National Weather Service said Philadelphia was on track for its third warmest summer since 1874. While 94° days are hardly pleasant for suburbanites, heat can be worse for residents in pockets of Center City, South Philadelphia, and North Philadelphia.

“In parts of Philadelphia called heat islands—on a hot day especially during heat waves—temperatures can exceed non-urban areas or Philadelphia suburbs by an average of 8 or 12°,” said associate professor of nursing Sara Jacoby, whose research lies at the intersection of health disparities and the sociostructural conditions of urban environments. She says heat islands can exist because of fewer trees and more concrete, and exposure to hotter temperatures and heat waves can pose health risks for people, especially those living with cardiovascular disease, asthma, and other chronic illnesses.

In Hunting Park, a North Philadelphia neighborhood, temperatures can be as much as 20° hotter than in other parts of the city. Operating out of the Lenfest Center, the nonprofit North10 serves the Hunting Park-East Tioga area by offering youth programs, workforce training, affordable housing, a community market, and more. Nikki Bagby, chief external affairs officer of North10, said people of all ages who come for services wait in the heat to catch a bus, and the bus stop has no overhang.

Researchers from Penn’s Weitzman School of Design, School of Nursing, and School of Engineering and Applied Science developed a novel prototype to address this issue: a solar-powered wooden bus shelter that provides shade and radiant cooling.

This is thanks to a grant from the Penn Community Collaboratory for Co-Creation (Penn4C), a joint initiative from Penn Nursing and Penn Engineering “based on the recognition that technological solutions should be designed with active engagement of marginalized communities.”

Dorit Aviv, an assistant professor of architecture and director of the Thermal Architecture Lab in the Weitzman School, led the research, design, and construction of the prototype with a team of students, while Dr. Jacoby provided messaging on the health impacts of heat and surveyed community members. The prototype is called Tenopy—a canopy created in collaboration with North10—and community members tested it out one day in August.

“We are aiming to provide an experience of being outside in the heat and then walking in here, sitting, and feeling relief while still being in an open-air structure,” Dr. Aviv said. “This can have important implications for how we think about urban cooling shelters for the future, especially given the need for open-air structures in light of what we’ve seen during the COVID pandemic. We also learned a lot from the community collaboration, and we hope that if the pilot is successful, we can work together toward long-lasting solutions.”

The prototype was designed as a temporary shelter, while installing a permanent structure involves material and structural enhancements and getting necessary permits for installation, Dr. Aviv said. She wants to see this experiment turned into a more permanent solution.

The cooling shelter came together this summer at Pennovation Works, Penn’s 23-acre site that contains labs, production spaces, and offices on the Schuylkill River. Beyond the garage doors into Dr. Aviv’s high-ceilinged fabrication workshop, she and students designed and built the 15-by-10-by-7-foot structure using basic two-by-four and two-by-two beams.

In addition to getting some shade, people using the shelter can sit on a bench with a conductive cooling surface or stand next to radiant cooling panels. Similarly to how radiant floors emit heat by circulating hot water through embedded pipes, pipes containing a refrigerant within the wall panels in the shelter provide radiant cooling. This is all powered by six small solar panels atop the structure that are connected to a heat pump and controls in the back, making the structure energy autonomous and renewable.

Adapted from a Penn Today article by Erica Moser, September 9, 2024.