Experimental analysis of a desiccant-based air conditioning sy-stem for a flower greenhouse

This paper presents an experimental comparative analysis between an innovative desiccant-based and a traditional air conditioning system for a flower greenhouse in winter season. The innovative air conditioning system based on H2O-LiCl desiccant consists of a dehumidi-fication unit in which the conditioned air is dehumidified by the strong desiccant solution and a regeneration unit in which the weak desiccant solution heated up by hot water is regenerated by scavenger air evolving in closed loop. A heat recovery is performed on the desiccant re-generation process. An auxiliary radiator driven by hot water completes the sensible heat needs of the greenhouse. In the traditional system the thermo-hygrometric control has been carried out by ventilation with outside air (latent load) and a radiator driven by hot water (sensible load). Two identical flower greenhouses working near Bergamo (Italy) have been equipped with a traditional and an innovative air conditioning system respectively. The experimental comparison shows a 10% average primary energy saving for the desiccant-based system with respect to the traditional one in the winter season. In addition, because the sanitising effect of desiccant and a more effective control of the humidity inside the green-house, the innovative system ensures also a consistent reduction in the use of pesticides with relevant economical and environmental advantages