Solar absorption cooling system for greenhouse climate control: technical evaluation

Evaporative systems are generally used in warm regions for commercial greenhouse cooling, such systems require large quantity of water that is often a scarce natural resource in Mediterranean areas. Solar absorption cooling systems can be applied for greenhouse climate control in regions with high values of solar irradiation as alternative to evaporative systems by exploiting renewable energy sources. The paper presents the preliminary results of a research on the application of a solar absorption cooling system to a Mediterranean greenhouse. The aim of the research was to assess the potential of the system in terms of energy absorption related to the solar collector surface and to the greenhouse covered area. The simulation study was realized based on the experimental data collected at the experimental centre of the University of Bari, Southern Italy, in order to control the temperature of a plastic film covered greenhouse, having a surface of 300 m2. The cooling system was designed by adopting suitable technologies of energy saving, in order to reduce cooling energy needs. The designed system consists of an absorption chiller having a cooling capacity of 35 kW and of 80 m2 of evacuated-tube solar collectors.