HALIFAX, Nova Scotia - An innovative cooling system at the Purdy's Wharf office and commercial complex here uses low-temperature seawater to meet building cooling requirements. Cold seawater is drawn from the harbor floor, circulated through titanium heat exchangers in the basement of the building, and then returned to the ocean floor. The building's cooling water is chilled by the seawater in the heat exchangers, and then pumped throughout the building. On each floor, the water circulates through a coil system, and a fan circulates building air through the coils to provide cool air.

For 10-1/2 months per year on average, the seawater system effectively cools Purdy's Wharf. During the remaining six weeks, cooling is provided by conventional chillers; however, the seawater is used to cool the condensers of these units.