A detailed heat transfer model of GAXAC (generator-absorber-exchange absorption compression) cycle using ammonia-water as working fluid is reported. The effect of UA (heat transfer conductance, kW/K) of each component on COP and cycle capacity is investigated. The results show that UA of the absorber and high temperature generator (HTG) have significant impact on COP and cycle capacity. For a capacity of 11.56 M the maximized COP with minimum UA value for all heat exchanging components is found to be 1.185. Further the effect of mass flow rate and inlet temperatures of hot fluid, chilled water and cooling water are also investigated. (C) 2009 Elsevier Ltd. All rights reserved.