The Wyss Lab at Harvard is doing some interesting work on reducing the power requirements of cooling systems.
Energy-Saving, Low-Cost Air Conditioning
Two new technologies could provide an eco-friendly cooling solution
Energy-Saving, Low-Cost Air Conditioning
Two new technologies could provide an eco-friendly cooling solution
"...EC units use 75 percent less energy than traditional vapor compression air conditioners, but because they add humidity to the air, they’ve only been suitable in dry desert climates. Now, coldSNAP is changing that.
The device—a unit of terracotta heat exchangers paired with fans and water pumps—is the size of a window. The ceramic part resembles a scaled-down mail cubby, with about 30 rectangular channels carved through it. Every other of these channels has been coated with a novel water-repellent material, while the rest is simply naturally porous, uncoated terracotta. Fans bring fresh air from the outside through the coated, cold terracotta channels, which cools the air. What makes the terracotta cool is an engineering trick: coldSNAP redirects some of that freshly chilled air into the uncoated channels, where water runs over the terracotta and cools the ceramic as it evaporates—like perspiration evaporating to cool the skin. The team’s water-repellent coating permits this heat exchange but is impenetrable to water—preventing moisture from entering the cooled dry air directed into the building. Right now, coldSNAP fits in windows, but eventually, the team hopes to integrate the device into building facades...
...This summer [2022] the team tested the product at HouseZero [their dedicated test building] during a brutal Boston heat wave. Even with the extreme humidity and high temperatures, preliminary data showed that coldSNAP cooled the third-floor room by more than 10 degrees Celsius [18ºF] without increasing the moisture content in the air. The researchers haven’t released specific energy usage data yet (because they plan to improve it even more), but so far, Grinham says coldSNAP is using “much, much less energy to do the equivalent cooling of an AC unit you’d have in your house. And all that, without refrigerants."
If they can make this fly (and at an affordable price), it could be a boon for our beleaguered electrical grids The device—a unit of terracotta heat exchangers paired with fans and water pumps—is the size of a window. The ceramic part resembles a scaled-down mail cubby, with about 30 rectangular channels carved through it. Every other of these channels has been coated with a novel water-repellent material, while the rest is simply naturally porous, uncoated terracotta. Fans bring fresh air from the outside through the coated, cold terracotta channels, which cools the air. What makes the terracotta cool is an engineering trick: coldSNAP redirects some of that freshly chilled air into the uncoated channels, where water runs over the terracotta and cools the ceramic as it evaporates—like perspiration evaporating to cool the skin. The team’s water-repellent coating permits this heat exchange but is impenetrable to water—preventing moisture from entering the cooled dry air directed into the building. Right now, coldSNAP fits in windows, but eventually, the team hopes to integrate the device into building facades...
...This summer [2022] the team tested the product at HouseZero [their dedicated test building] during a brutal Boston heat wave. Even with the extreme humidity and high temperatures, preliminary data showed that coldSNAP cooled the third-floor room by more than 10 degrees Celsius [18ºF] without increasing the moisture content in the air. The researchers haven’t released specific energy usage data yet (because they plan to improve it even more), but so far, Grinham says coldSNAP is using “much, much less energy to do the equivalent cooling of an AC unit you’d have in your house. And all that, without refrigerants."
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