The application of Het Nieuwe Telen (the New Style of Cultivation) in Dutch greenhouses is strongly dependent on the use of one or more movable screens. However, an objective comparison of screen materials under dry and wet conditions is difficult. Two projects have attempted to change this. The researchers now report on Kas als Energiebron.
The objectives of the projects 'Measuring wet screens' and 'Expanding wet screens and screen use' were to quantify the screen properties through standardized measurements: thermal properties such as emission, aerodynamic properties such as air permeability, and moisture transport. From the measured screen properties, the total potential energy savings can then be calculated, under predefined conditions. The results from the wet screen study show that screens with low permeability and low emissions offer the greatest energy savings.
Two of the screen samples used in the wet screen study
According to the researchers, screen manufacturers should focus on developing screens with low permeability and simultaneously low emissivity. These provide the highest energy savings; up to 43% during the night according to the study.