ISHS Acta Horticulturae 719: International Symposium on Greenhouse Cooling
EVAPORATIVE COOLING IN GREENHOUSES: EFFECT ON MICROCLIMATE, WATER USE EFFICIENCY AND PLANT RESPONS |
| Author: | J.I. Montero |
| Keywords: | Greenhouse cooling, fog system, ventilation, leaf temperature, fruit temperature, blossom end rot. |
| Abstract:
Evaporative cooling occurs as a result of the conversion of sensible heat into latent heat in mechanically supplied evaporated water. This article presents results from models based on energy and mass conservation to study the interaction between external and greenhouse climates, paying special attention to the relationship between ventilation rate, evaporative cooling and greenhouse temperature. Leaf temperature as affected by the external air humidity regime is also discussed and a design for evaporative cooling system requirements relating to air mass and evaporation flow rates is outlined. Water uptake is a function of the greenhouse vapour pressure deficit (VPD) and is therefore affected by evaporative cooling. Some results relating to water uptake and water use efficiency in fog-cooled greenhouses are also discussed. Plant response to evaporative cooling is not always positive, since physiological disorders like Blossom End Rot (BER) may be fostered under high radiation and high humidity conditions. Finally, future research trends including some possible ways of improving the efficiency and control of evaporative cooling systems are also outlined. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
