Med school plan utilizes
sea water in air conditioning
Water Board members approve
$1.6 million to study such a system
Sea water pumped from 3,000 feet would be the chilling agent in the air-conditioning system for the University of Hawaii medical school in Kakaako under a plan given preliminary approval yesterday by the Honolulu Board of Water Supply.
The "district cooling" method would use less electricity than conventional air conditioning and conserve fresh water, chief engineer Clifford Jamile told the board.
Board members approved $1.6 million for a feasibility study. They voted unanimously to use money previously budgeted for a Beretania line booster station, deferring that appropriation until the 2005 budget.
Jamile said the total project cost would be between $3.5 million and $6 million, including development of a deep sea-water well on the medical school site and construction of a cooling plant. The cost would vary, depending on what is discovered about deep-water temperatures, he said.
The "district cooling" method is used at Cornell University, where deep water from Cayuga Lake is the chilling agent, he said.
"District cooling is a proven technology to deliver chilled water to buildings for air conditioning and eliminate the need for central cooling plants in buildings," Jamile said.
A conventional building cooling system uses electrically powered compressors to circulate air chilled by a refrigerant gas.
Jamile said conventional air conditioning for the medical school complex would require a plant with the capacity of 4,000 tons of refrigeration. The plant would evaporate 30 million gallons of potable water a year into the air.
"We could use nature's cold water to provide the cooling effect," he said. "We know water, we know wells, we know pumps. It's very simple. It's an idea whose time has come."
Jamile said the Board of Water Supply has not yet determined what environmental impact reports will be required and how it would affect the timing of the project. "We are working fast because the medical center has moved ahead quickly."
He said city engineers envision expanding the "district cooling" project to serve other buildings in Kakaako. "The development of additional cooling capacity can be programmed to coincide with the expansion of biotechnology and research properties, as well as cultural, recreational, retail and commercial developments as part of the Kakaako Waterfront Master Plan proposed by the Hawaii Community Development Authority," he said.
Board officials have had discussions with the Kakaako authority about securing land for additional deep wells and cooling plants, he said.
"The board has been looking at the district cooling approach for some time," Jamile told the board.