Microencapsulated phase change material (MPCM) slurry is advantageous for thermal storage systems to use as a heat transfer and storage medium. In this paper, a new design of air-conditioning system is proposed, which is a combination of CC and a MPCM slurry storage tank. The mathematical model of the combined system is provided and used to predict the system performance of an office room under Hong Kong weather condition using hour-by-hour calculations. A feasibility analysis for the combined system was also made with computer calculations. The results indicate that a small MPCM slurry storage tank is able to shift the part of cooling load from the daytime to nighttime. It is also revealed that the proposed combined system is an energy saving and economy-favorable air-conditioning system. (c) 2008 Elsevier Ltd. All rights reserved.