ISHS Acta Horticulturae 797: International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions
GREENHOUSE COOLING WITH CONTINUOUS GENERATION OF UPWARD-MOVING FOG FOR REDUCING WETTING OF PLANT FOLIAGE AND AIR TEMPERATURE FLUCTUATIONS: A CASE STUDY |
| Authors: | K. Ohyama, T. Kozai, H. Toida |
| Keywords: | continuous generation of fog, fan, latent heat, natural ventilation, sensible heat, water-sensitive paper |
| Abstract:
The performance of a proposed cooling system with continuous generation of fog was compared with that of a conventional cooling system with intermittent generation of fog in a naturally ventilated greenhouse. In the proposed system, upright nozzles were placed above small fans such that the upward-moving air dispersed the fog. On the other hand, in the conventional systems, nozzles were installed pointing slightly upward without any forced air stream. Analyses using water-sensitive papers showed that fog adhesion to the plant foliage and dry bulb temperature were, respectively, approximately 60% and 2.4°C lower in the proposed system than in the conventional system at an almost constant fog generation rate, indicating a much higher fog evaporation ratio in the proposed system. Our results showed that the proposed system will help reduce wetting of the plant foliage and fluctuations in air temperature and relative humidity during greenhouse cooling. | |
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