Efficiency of a gas turbine is closely related to the intake air temperature. An increase in the intake air temperature will results in the decrease of the turbine efficiency. This paper presents the study of various offset strip-fin surface geometry for the design of a heat exchanger at providing a constant air temperature at the inlet side of the gas turbine irrespective of the change in ambient temperature. The design took into account the need to employ the available chilled water system from the cogeneration district cooling plant as the cooling media. Twelve combinations of offset strip-fin surface geometry pairs were studied in order to determine the optimum design for the heat exchanger. The results showed that 1/8 - 20.06 (D) for air side and 1/8 - 16.00 (D) for the chilled water side would provide the highest heat transfer coefficient with a good overall passage efficiency and fin efficiency. © 2011 Published by Elsevier Ltd.