A Large part of operating costs of a hotel in Hawaii is the cost of energy for air conditioning. Building can be constructed to use energy more efficiently by using many methods, however, some of these method conflict with other concerns, aesthetics for example. Thus the process of designing and building an energy efficient hotel often involves trade-offs between energy efficiency and other objectives. The method proposed herein to reduce energy costs is to introduce seawater, pumped from the deep ocean at a temperature of approximately six degrees celsius, directly to heat exchangers which cool the chilled water circulating in the building air conditioning system. The energy required to run the system would be reduced to only the cost of the seawater pumps, the fans and controls. The savings would be in the operating costs of the seawater pumps versus the cost to the compressors of a conventional air conditioning system.