Microclimatic Modeling and Analysis of a Fog-Cooled Naturally Ventilated Greenhouse

In the present paper, a thermal model has been presented for predicting the thermal environment inside a fog cooled naturally ventilated greenhouse. Experiments were conducted on a polyethylene covered greenhouse having 250 m2 ground area located at Coochbehar (latitude: 26.2o N, longitude: 89oE), West Bengal, India. The greenhouse was cooled by intermittent fogging with three distinct fogging cycles during the experiments. The greenhouse air temperature profiles as predicted by theoretical model were validated for different fogging cycle configurations. The model prediction and experimental results build up a good match (co-efficient of correlation was in range of 0.85 to 0.97). It was observed that fogging cycle configuration (spray time and spray interval combination) influences greatly the cooling performance of the fogging system. Further analysis revealed that greenhouse temperature could be maintained 2-5oC below the ambient temperature by employing suitable fogging cycle, maintaining the relative humidity within acceptable level