Experimental Investigations on Evaporative Condensers Performance

The evaporative condensers operate at lower condensing temperatures compared with dry heat transfer units when connected to the same refrigeration system, as well as involve less water and reduce the pumping power associated to cooling towers. These characteristics are strictly correlated with the evaporation process. For these reasons they are conveniently used for heat rejection in big industrial plants and recent technological developments have made it possible to exploit their higher efficiency even in smaller air conditioning systems. In this work a test rig for the evaporative condensers performance analysis and the relevant experimental activities are presented. The combined effect of the dry bulb temperature and relative humidity on the system performance has been investigated. The maximum reduction of the heat transfer rate, due to an increase of 6 % of the initial value of relative humidity, results of 30 % for the highest dry bulb temperature. The air processes plot in a psychrometric chart show that the latent to sensible heat transfer ratio decreases with relative humidity.