MODELING OF INDIRECT EVAPORATIVE AIR COOLERS

The modelling of indirect evaporative air coolers is discussed and three calculation models are described. Sample calculations show that the optimum shape of the cooler unit would result in a primary to secondary air velocity ratio of about 1.4, assuming thal the primary and the secondary air mass flow rates are the same and that the same plate spacings are used on the primary and secondary sides. In conclusion it is found that the simplified model gives good results and is recommended for the evaluation of smaller systems and for initial design purposes while the more sophisticated methods shoUld be used for more accurate performance prediction.