Hawaiian university to build seawater-powered air conditioning system

The price of air-conditioning in Hawaii could cost a lot less if a newly proposed project is successful. The University of Hawaii plans to drill 3,000 feet beneath the island of Kaka’ako to help cool the air conditioning units for the new John A. Burns School of Medicine, which is under construction.

Although salt water has been used in the past to help cool air conditioning units in office and school buildings nationwide, the conventional systems use horizontal pipelines that are miles long to reach cold lake and ocean water, and can costs tens of millions of dollars.

Planners from the Honolulu Board of Water Supply hope to instead drill straight under the building and tap into cold seawater beneath the island, and then pump it up to the air-conditioning units. According to the board, it could save the University of Hawaii Medical School $750,000 every year in air-conditioning costs. If successful, the project could affect the way other buildings are cooled on the main island of Oahu.

Clifford Jamile, the chief engineer of the project, came up with the idea when construction workers drilled a 1,600-foot well at a desalination plant in Kalaeloa. The water at the 1,600-foot level was 53 degrees, almost cold enough to be used for air-conditioning. Ultimately, planners for the project aren’t sure what the temperature of the underground seawater will be at the university site, but hope that it will be in the low 40s. If it is in the low 50s, it can still be cooled and then used for air-conditioning. If the saltwater is any warmer, the university will have to abandon the idea and use conventional cooling methods.

The new pump system is expected to cost between $3.5 million and $6 million. It will pump 10 million gallons of saltwater a day and provide the school an 85-percent savings over conventional cooling costs. The planning board also looks at the project as a water conservation measure that would save valuable drinking water from being used in cooling systems.

The first medical building, along with the new cooling system, is expected to be in operation in March 2005.