Optimisation of the capital cost of a cold-sea-water, closed-loop cooling system for a large air-conditioning unit is presented. The cooling system is designed to use the conventional refrigerant-type chiller as a backup unit. The system is optimised by varying the diameter of the pipe and the temperature at the inlet to the cold-sea-water chiller. Includes a case study proving the ideas presented.

KEYWORDS: optimisation, chillers, cold, sea water, cooling, case studies, costs, calculating, heat exchangers, energy consumption, energy conservation, cooling load, air conditioning