Friday, September 12

Air-Conditioning Cities With Deep Water

Virtually any city or town next to a lake, ocean or river could pump chilled water from the depths for natural air cooling

China is considering using deep ocean water to aircondition Hong Kong.

The high rise office buildings of Hong Kong; man-made "cliffs"-- are right next to the ocean. This makes it easy to cool them, by leveraging the differential between the cold ocean depths and warm surface temperatures.

Hong Kong will circulate deep ocean water through a district-wide cooling system.The water is pumped to a heat exchanger at the shore and the warm water from the buildings flows down to push cool water up to the buildings. The system is both elegant and cost effective.

Similar projects to cool large building complexes and downtown areas are underway in Singapore, Gibralta, Stockholm and Honolulu.

The same technique can be applied using the cold depths of lakes and rivers too. And not just for cities. This natural cooling be used by smaller communities like universities, hospitals or hotel resorts.

Cornell University has a pilot project utilizing lake water for its cold water source. Pumps draw cold water from a nearby deep lake, Lake Cayuga.

Enwave also uses lake water, to cool downtown Toronto. Their interactive diagram shows you very clearly how their deepwater cooling works using the icy-cold water of Lake Ontario as its renewable energy source of naturally chilled deep lake water.

How fortunate that all through history, we built so many towns and cities near water. Back then, that was because it was easier to move stuff along waterways. Early roads got muddy, but water made for easy hauling.

And now that we are looking for low-carbon alternatives, that fortuitous proximity to water comes in handy for another use. Eco air-conditioning.

Published at Matter Network