In 2018, researchers from Princeton University, the University of British Columbia, the University of California, Berkeley and the Singapore-ETH Centre built a “Cold Tube,” a radiant cooling system in Singapore in attempt to cool people outdoors in extremely hot and humid conditions. The outdoor pavilion was cooled using panels that were chilled by cool water pipes running inside them.
Forrest Meggers, assistant professor of architecture and the Andlinger Center for Energy and the Environment, co-leads the research, which has now shown that their radiant cooling system effectively kept people cool outside, with little energy cost and without air conditioning. In a paper published August 18 in the Proceedings of the National Academy of Sciences, the researchers reported that occupants felt comfortable in conditions that reached 30 degrees Celsius (or 86 degrees Fahrenheit). The researchers had conceived of an airtight, humidity-repelling membrane to encase the chilled panels, preventing condensation from forming, while still allowing radiation to travel through.
“Because the Cold Tube can make people feel cool without dehumidifying the air around them, we can look towards shaving off up to 50% of typical air conditioning energy consumption in applicable spaces,” said first author Eric Teitelbaum, who worked on the project as part of his doctoral research as a Princeton Ph.D. student in architecture.