Simulation of a desiccant air-conditioning system integrated with dew-point indirect evaporative cooler for a school building

In this study, a desiccant based air-conditioning system supported by a dew-point indirect evaporative cooler, a direct evaporative cooler, two heat recovery units was investigated during a complete cooling season for air-conditioning of a school building located in Adana, Turkey. A mathematical model of the air-conditioning sys-tem was developed by deriving new equations for modelling two key components of the system, namely desiccant wheel and dew-point indirect evaporative cooler using the available correlations and experimental data. Effectiveness of desiccant wheel and dew-point evaporative cooler, heat transfer rates realized in the main system components, the thermal energy requirement to drive the system and cooling performance of the system are investigated thoroughly. The effect of desired building indoor air temperature and mixing ratio of exhaust air on the operation and performance of the system was detailed. The results show that it is possible to obtain desired comfort conditions within the building during complete cooling season with the air-conditioning system considered. The monthly average thermal COP is maximum in October with 0.78 and minimum in July with 0.22. The seasonal thermal COP of the system is 0.43.