DWSC Case Histories

Purdy's Wharf, Halifax Harbor, Nova Scotia, Canada

In 1986, Purdy's Wharf Development, Ltd. constructed a system to use ocean water to cool two commercial buildings totaling over 300,000 square feet along a waterfront location in Halifax, Nova Scotia. Twin, polypropylene intake lines were laid to a depth of approximately 75 feet in the narrow strait offshore. The system works in conjunction with motor driven centrifugal chillers to meet the total annual cooling load of the buildings.

Nova-Scotia Power, Nova-Scotia, Canada

The local utility serving the City of Halifax is studying the potential of using a scaled-up version of the Purdy's Wharf system in a district cooling project aimed at serving the harbor front section of the city.

Natural Energy Laboratory of Hawaii Authority, Keahole Point, Hawaii

The National Energy Laboratory constructed a pilot plant that has used cold ocean water to cool a selected facility building since 1986. Based upon the success of the pilot plant, a second building has been added to the system.

West Beach, Oahu, Hawaii

A study prepared for the State of Hawaii, Department of Business, Economic Development and Tourism, Energy Division was completed in September 1994. The study evaluated the technical and economic feasibility of using cold sea water to cool a centralized DWSC system for a new master planned development on the island of Oahu. The study extensively evaluated several system configurations and load scenarios. The system evaluated DWSC configurations ranging in size from 1,300 to 12,700 peak tons. The study concluded that an ocean based DWSC system is a technically feasible and economically attractive alternative to conventional, chiller based systems for this application

Stockholm, Sweden - Stockholm Energy

Recently completed a DWSC system that uses deep, cold ocean water to cool a large portion of downtown Stockholm. The system was reportedly completed in May 1995. The peak cooling capacity of the system is approximately 17,000 tons.

Toronto, Canada

A well documented, fresh water DWSC system study was prepared evaluating the feasibility of using cold Lake Ontario water to cool a portion of the City of Toronto. Canada. The DWSC facility proposed would service much of downtown Toronto and satisfy an anticipated cooling load demand on the order of 300.000 tons anticipated in 2015. To gain perspective, this cooling load would require as much as 600.000 gpm of Lake Ontario water to accommodate the peak cooling demand.

Miami, Florida

A feasibility study considering the use of cold ocean water for the cooling of several commercial districts in Miami was performed for the U.S. Department of Energy, (DOE). The study included approximately 20,000 tons of cooling load from newer shoreline hotels and apartment complexes using as much as 50,000 gpm of cold sea water. The sea water intake was at an offshore depth of 700 feet and at a point approximately 22,000 feet from shore. The study concluded that a DWSC facility was technically and economically feasible for this particular application.

Xerox, Webster, New York

An in-depth feasibility study was conducted to assess the potential for using cold Lake Ontario water to provide comfort cooling for a large manufacturing and administrative campus in upstate New York. The system was unique in that it was combined with the expansion of the local municipal water districts' treatment facility.

Cornell University, Ithaca, New York

A DWSC system for Cornell is currently being studied and evaluated as a viable alternative to replacing the existing conventional chiller based, chilled water production system.