ISHS Acta Horticulturae 148: III International Symposium on Energy in Protected Cultivation
THE INFLUENCE OF CLIMATIC CONDITIONS ON THE HEAT LOSSES FROM CONVENTIONAL AND SLOPING GREENHOUSES |
| Authors: | N. Zamir, G. Medan, A. Arbel, N. Levav |
| Abstract:
Measurements were taken of the temperatures, relative humidities, wind direction and velocities, and quantities of heat that had been supplied to the greenhouses of the Givat Hananya Experiment Station during the winter of 1981/82. It was found that when there is no wind and the relative humidity is 100%, 5.6 keal/h/m2 of cover is needed for every 1°C difference, to overcome the heat losses from the greenhouse. This value rises as a relative humidity decreases and wind speed increases, according to the formulae:
where u is the heat loss in kilo calories per sp.m per hour per degree cent.diff., R.H is relative humidity in per cent, and v is the wind velocity in m per sec. | |
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