Cooling Off from the Bottom of the Sea

The Associated Press ran a fascinating story about using seawater for air conditioning. Technology’s answers to life’s challenges are indeed clever.

A $100 million system proposed for downtown Honolulu could reach about 65 buildings, including several state office buildings, said David Rezachek, associate development director of Honolulu Seawater Air Conditioning, which is working with Kailua-based Makai to put cold seawater technology to work in Hawaii.

Once underground pipes leading from an oceanside plant are in place beneath the city streets, buildings would be able to tap into the system and save about 75 percent of the electricity used by conventional cooling systems, said Rezachek.

The technology is relatively simple. Cold ocean water is pumped up to the plant through a closed system, cooling down fresh water in an adjacent system. That cold fresh water is then used by buildings to bring down the temperatures of their interiors, similar to a conventional air conditioning system.

The University of Hawaii has built a similar system using deep seawater wells for its new oceanside medical school buildings near downtown Honolulu.