THE EFFECT OF AN EXTERNAL MOVEABLE SCREEN ON THE GREENHOUSE MICROCLIMATE: AN APPLICATION OF A ONE DIMENSIONAL NUMERICAL MODEL

The extension of the greenhouse growing season throughout the entire year, placed the grower with the need to cool and shade the greenhouse in the hot climate especially during the day, in order to provide the plants with appropriate climate conditions.
An external movable screen (EMS) mounted over the greenhouse roof can control radiation level and temperature, and give additional protection from various climate related diseases and sudden weather changes.
The EMS is more efficient in humid areas where the evaporative cooling methods are not sufficient; it is more energy conservative then a constant screen laid on the greenhouse roof since it is applied only when radiation conditions require it.

To predict the microclimate inside a commercial greenhouse equipped with an EMS a one dimensional numerical model was adapted.
Measured meteorological parameters inside the greenhouse were used to test the model performance.
Good agreement between the predicted and measured parameters was achieved.
This model provides the grower with an efficient tool capable to determine the most efficient screen for his greenhouse (before setting up the screen) with respect to the local climate conditions and specific crop needs as well as economical considerations.

International Conference on Greenhouse Technologies

N. Pass, Y. Mahrer

Temperature, humidity, optimal control

https://doi.org/10.17660/ActaHortic.1997.443.14