The purpose of external screens is to regulate the climate in the greenhouse better. This can be achieved by ‘screening out’ certain weather factors on the outside of the greenhouse.
Excluding sunlight ensures lower insolation and a lower temperature in the greenhouse. Also, through reduction in the cooling load, lower electricity consumption can be achieved. The roof vents can stay closed longer, which leads to improved CO2 concentrations.
In the colder months, energy savings can also be made thanks to the insulating effect of the external screens.