Objetivo
To demonstrate energy savings in greenhouse cultivation and the durability of a concertina type thermal screen. The estimated energy saving will be 170 toe per annum for a 10,000 m2 greenhouse, in comparison with a similar greenhouse without thermal screen. A new cross laminated structure for the screen provides a more durable screen.
The project has shown that the metallized Valeron screen induces an energy saving of 35% in average, compared with a computer simulated identical greenhouse but without screen, reducing the natural gas consumption from 62 m3/m2xyear to 40 m3/m2xyear.
This corresponds to an annual energy saving of 177 toe for the greenhouse.
The payback time amounts to about 4 years, taking into account that the lower light losses give a 3% production increase,
The project has also shown that the concertina metallized screen is able to control the climate underneath the screen by means of very narrow screen openings. However, this screen has a low water vapour permeability while the growers already using screens are accustomed to screens with a high water vapour permeability, although this property renders the climate control more complicate.
Since the implementation of the project, the metallized screen has been regularly sold as side screen, comparting and door screen.
The use of the Valeron screen as horizontal screen has not made a break-trough yet, notably for the reason mentioned above.
Energy savings will be demonstrated in a 10,000 m2 chrysanthemum nursery. The concertina type screen is a complex polyester/aluminium film. The cross-laminated structure gives the film greater strength and durability than existing screen materials. The concertina structure also allows the screen to be tightly bunched when not in use, reducing light losses by 3% in comparison to other thermal screens.
The screen is operated by a computer controlled system driven by electronic motors. Though principally used to reduce heat loss and provide total darkness during 13 hours a day, the screen can also be used to control climatic conditions. This is achieved by adjusting very narrow openings of less than 1 cm wide.
The estimated payback time amounts 7.1 years when based only on energy savings, and to 4.5 years when taking also into account the increase in productivity linked to lower light losses.
Tema(s)
Convocatoria de propuestas
Data not availableRégimen de financiación
DEM - Demonstration contractsCoordinador
1096 BK AMSTERDAM
Países Bajos