Prediction of performance of a cellulose evaporative cooling pad system using stepwise regression method and investigation of the impacts of effective parameters on the water and electricity consumptions

Stepwise regression method (SRM) was employed in order to develop simple and accurate models for prediction of supply air temperature and pad’s pressure drop of a cellulose evaporative cooling pad system. After validation of the obtained models, influence of variation of effective performance parameters on water and electricity consumption of a cooler which supplied a specific volume of cooled air providing thermal comfort conditions was studied. Furthermore effects of variation of these parameters on resources consumptions costs (RCC) for Iran and the USA as countries in which water to electricity price ratios are low and high respectively were investigated. The results showed that RCC does not depend on the inlet air temperature variation. Additionally in low water to electricity tariffs ratio countries such as Iran, the inlet air relative humidity doesn’t have any effects on RCC too. Moreover for these two countries the best values of pad thickness, pad specific area and ‘a’ incidence angle are the minimum of them by which thermal comfort condition can be met (0.05 m, 350 m2.m-3 and 45 degrees for the investigated case). In addition, there is a threshold specific contact area in which RCC starts to increase dramatically. The values of this threshold that is dependent on the water to electricity tariffs ratio for Iran and the USA are 405 and 435 m2.m-3 respectively.