Agriculture Reference
In-Depth Information
Photo 8.6.
external shading device located over the greenhouse. The vents have anti-insect screens.
Support thread
Fixing
Thread
Rail
Mobile roller
Fixed roller
Support tube
Fig. 8.11.
Different systems for fixing and moving the screens (adapted from Urban, 1997a).
of the solution used (additives) and of the
rain, which may wash them off.
Internal screens do not have to be as
resistant as the external ones and there is a
wide range of them on the market (see
Chapter 4). The internal shading screens
must be permeable to the air to facilitate
ventilation. The use of aluminium sheets
woven into the screen or use of aluminized
plastic film, allows for the reflection of the
solar radiation. So, in the case of alumin-
ium-based shading screens, they must be
placed with the aluminium side on the
upper face, whereas in the case of energy-
saving screens the aluminium must be in
the inner (downwards) face.
