Throwing Shade

Woods Bagot’s Over/Under Kiosks along New York City’s South Street Seaport waterfront in Lower Manhattan represent a combination of seasonal and programmatic design strategies that inform the best public spaces—primarily consisting of 150-square-foot spaces for pop-up refreshment stands, they also act as shading and seating. Built with aluminum cylinders and a simple internal structure, the kiosks use formal inventiveness in the design of an intentional urban microclimate, or perhaps even a micro-microclimate of shade done well.

And shade done well, even when just a tiny intervention, is something anyone who lives in a city these days—most of humanity, in other words—undoubtedly appreciates. The summer that we are leaving behind in the Northern Hemisphere was another one for the record books. Extreme temperatures, nonstop heat waves, and mega-droughts became everyday headlines for cities as diverse as London, New Delhi, and Vancouver. As I embark on my Australia trip, I ask myself what sort of stories I would want to share with my friends in the Southern Hemisphere as they start drifting into their own version of summer.  

Last month when I was visiting New York, we ventured out to the Seaport to take some thermal images of the kiosks to visually document their microclimate contribution. The difference in temperature between unshaded and shaded surfaces is about 10˚C on a relatively mild day in September. While the ambient temperature would remain the same, of course, these surfaces exchange heat with our bodies through a radiant process, which can make us feel warmer. If we are also exposed to direct sun, we are effectively ramping up our heat gain. In the winter, that may be useful, but for me—wearing a light sweater and a jacket to help me layer against variable conditions in New York—I wanted to avoid direct sun as much as possible. There was also the added benefit of reducing glare, or excessive daylight, which I appreciate as a light-sensitive person.

Using a relatively reflective material for the cylinders also ensures the kiosks do not unnecessarily absorb more heat than needed, which could then artificially heat up the surrounding boardwalk, even after the sun had gone down. That is a simple explanation for what we call Urban Heat Island (UHI) effect, which is a human-designed problem that is exacerbating the extreme heat conditions that increasingly present serious public health issues for cities. 

Urban heat and glare are only two aspects of urban microclimate design. We could also talk about wind-driven rain or air quality. Most of these conditions can be effectively modeled in design, while all of them can be observed at work in the city by anyone with a thermal imaging camera or some other device and some time on their hands. As I like to tell my students, whether you intentionally design it or not, your project will produce microclimate effects on the pedestrian experience of the city, so why not be intentional? 

There is certainly an expanding body of research on the subject. For urban heat islands, I have long relied on the excellent research about Los Angeles that was championed by the late University of Southern California professor, George Ban-Weiss. He contributed to so many groundbreaking studies of urban heat in Los Angeles that it is hard to point to just one aspect of his work, but I would argue the studies he and his colleagues produced around the benefits of cool roofs in new buildings and retrofits to not only reduce urban heat island, but to also potentially improve air quality in LA neighborhoods, may have the most lasting effect on my hometown. And it is relevant for any city, but definitely cities facing significant periods of extreme heat in their summer months and looking for a science-based approach to crafting policy.  

Some of Ban-Weiss’s other notable projects included testing theories around deploying cool pavements on the many miles of street surfaces in LA, an approach that demonstrates a reduction in urban heat island effects in both analytical models and prototypes, but in actual use could also present issues for pedestrians who may be walking on those same surfaces that are now reflecting heat upward. That is the challenge we face as designers—balancing environmental issues with comfort, weighing each material choice against multiple criteria, and developing a reasonable and quick way to assess the microclimate implications of our design in both design and use.  

Of all of the stories about extreme heat in cities I read this summer, the one that struck me the most was the New Yorker article about the heat wave in India, reported by a doctor who went out into the heat to see how it affected everyday lives. It is a tough article to read, especially sitting in an air-conditioned office in Los Angeles, but what I took away, at least as a designer, is that getting out of the office and talking to people may be our best tool in the face of unprecedented climate change. Measuring actual conditions, rather than modeling them on a computer, and asking people how they feel are critical for addressing a climate crisis that behaves in unpredictable ways—the evidence we need is outside, all around us. If you need a good, cheap thermal imaging camera, I recommend the FLIR One Gen 3. 

@rfortmeyer

WHAT AM I READING?

Heat Smart: building resilience to heatwaves in Western Sydney, Australian Journal of Emergency Management

Reduce Urban Heat Island Effect, United States Environmental Protection Agency

The world’s whitest white paint is coming for cars, planes, and spacecraft, Fast Company

Image credits, top to bottom: Over/Under Kiosks, Lower Manhattan, New York. Photo by James Ewing – woodsbagot.com; Photo of the author capturing thermal imaging of Woods Bagot's Over/Under Kiosks in Lower Manhattan, New York; Urban heat island effect mitigation diagram from "Investigating the Urban Air Quality Effects of Cool Walls and Cool Roofs in Southern California." Co-authored by George Ban-Weiss. Reprinted with permission from Environmental Science & Technology. Copyright © 2019, American Chemical Society.