Abstract
This paper presents the development of the numerical model of a hybrid cooler. It is based on a modular and generic coil geometry that deals with any staggered coil and pipe arrangement. Particular attention is given to model the spray water system and to the calculation of water evaporation on the coil surface. It is validated by monitored data from a pilot system installation in which a commercial hybrid cooler is operated under typical summer south European working conditions. The numerical model has an average error of 7 % for the rejected heat and 0.1 % for the fan power consumption. The model is compatible with TRNSYS simulation software. It can be used for design and product development purposes by HVAC manufactures and thermal engineers.