ISHS Acta Horticulturae 51: Symposium on Protected Cultivation of Flowers and Vegetables
REDUCING THE HEAT REQUIREMENTS OF A GLASSHOUSE |
| Authors: | B.J. Bailey, K.W. Winspear |
| Abstract:
Owing to the increasing cost of fuel for greenhouse heating, there is growing interest in methods of reducing consumption. Film plastic blinds used for photoperiod control form the basis of one way in which heat losses from greenhouses, and consequently fuel consumption, can be reduced. When these are drawn over the crop the heat transferred by convection and condensation to the greenhouse surface is reduced, as also is the radiation loss from the plants. Measurements were made of the heat consumption of two commercial glasshouses at different locations with and without black polyethylene covers drawn over the crop at night. The heat input was determined by measuring the flow of condensate leaving the glasshouses. When the covers were in position it was found there was a reduction both in the heat loss at a given wind speed, and in the effect of wind speed on the heat loss. The heat requirement of the houses was reduced on average by 35% when using the covers. It was calculated that the annual fuel saving in the South of England would be 20% if the blinds were used at night throughout the year. | |
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