Water-cooled packaged air-conditioning systems are reevaluated in terms of alleviating the heat island phenomenon in cities and effectively utilizing building rooftops. Up to now, such reliability assessment has been insufficient, and this has limited the use of this kind of air-conditioning system in the information and communications sectors that demand a high reliability. This work has led to the development of a model for evaluating the reliability of water-cooled package air-conditioning systems. The model clarifies the behavior of air-conditioning systems when they fail, and quantitatively assesses the reliability of air-conditioning systems based on the redundancy and number of partitions of cooling towers. These results will be very useful for designing water-cooled package air-conditioning systems based on reliability.
