The science can be surprising. As big chunks of the United States and Canada roast through the weekend, some of these ideas might be worth a closer look.
Water That Sidewalk
In Japan’s sweltering summer months, you might see storekeepers with a bucket of cold water, dousing hot pavement outside their stores.
A 2018 study in the journal Water found that uchimizu caused air temperatures to drop by as much as 10 degrees Fahrenheit near the ground, even with small amounts of water.
According to Shigenori Asai, director of the Japan Water Forum, the more neighbors join in and douse the pavement, the more effective it is. “You might even feel a cooling breeze,” he said. His group is sponsoring a global Uchimizu Day on Aug. 1.
Hang Screens of Fragrant Grass
Before air-conditioning, people in some of the hottest parts of India survived intense heat waves by weaving screens made from the spongy roots of a sorghumlike grass called vetiver.
The screens are kept wet and hung over doors and windows facing the wind for another version of evaporative cooling. Hot air blowing through is stripped of some of its heat. The grasses also smell good.
The process works so well, especially in dry environments, that some modern data centers are turning to a variation of this idea called indirect evaporative cooling.
If old-fashioned technologies like this can make a dent in the expected surge in air-conditioning use in India and other countries, that would bring great benefits, said Liza Raju Subhadra, an architect in Kerala, India, who works with alternative materials.
“It’s not just energy-intensive — when a neighbor uses an air-conditioner, the hot air gets passed onto me,” she said. “It makes a big difference if we can passively cool our homes.”
Wear Dark, Flowing Robes (or Seersucker)
It may seem counterintuitive to wear heavy, dark clothing in the desert, but communities in the Middle East and North Africa have done so for centuries.
A study published in Nature in 1980 found that dark robes can indeed create a cooling effect when worn in loosefitting ways. The robe absorbs heat and warms the air inside the garment, but as that hot air expands and rises rapidly, it escapes through the top. The upward flow acts like a pump, drawing cooler air from the bottom of the robe.
“The additional heat absorbed by the black robe was lost before it reached the skin,” the authors concluded.
For a different look, try seersucker. In the hot, humid summers of the American South, linen and seersucker, the thin, puckered cotton fabric, are staples.
Seersucker is woven in a way that causes some threads to bunch together, giving the fabric its distinct wrinkled texture. That prevents it from flattening and sticking to sweaty skin. It also creates tiny pockets that aid air circulation and cooling.
by Hiroko Tabuchi, NY Times | Read more:
Image: The Yomiuri Shimbun, via Associated Press
[ed. And there are other options too, from architectural to personal/practical. My buddy Jerry was telling me about folks in Texas who used to, maybe still do, dig small pit caverns (like root cellars) a few feet below ground with an attached conduit routed upward into their house. The cool air from just a few feet below ground is enough. Another option would be architectural design, see also: How Old Dubai's historic streets beat extreme heat (BBC).]
