From a simple energy balance for the thermally driven chiller, the specific primary energy consumption of the dry cooler and the cooling tower per unit of heat rejected, PEspec, cooling tower, including the electricity needed for the circulation pump of the cooling water cycle, can be expressed as follows:

In this equation Espec, coolin tower is the specific electricity demand of the cooling tower per unit of cooling energy (heat rejection) including the circulation pump of the cooling water cycle and it is expressed in kWhel/kWh

cooling, [13].

In addition to the above defined specific energy consumption, the total cooling energy produced by the chiller, the electricity consumption of the fans and the water consumption were calculated with TRNSYS and reported in Table 2. The simulations were conducted for an entire cooling season, (middle of June to middle of September).