Agriculture Reference
In-Depth Information
80
60
40
20
Flat roof
Symmetrical roof
0
7
8
9
10
11
12
13
14
15
16
Solar time (h)
10
East
West
North
South
100
80
60
40
20
0
Roof
angle
15°
2
5°
3
5°
2
5°
65°
Circular
Gothic
Elliptical
Plate 9.
Hourly evolution of transmissivity on 21 December in a low-cost, flat-roof greenhouse and in a
greenhouse with a symmetrical roof with a 220
m cover of thermal PE and a 15° roof angle, oriented east-west.
Plate 10.
Transmissivity of different greenhouse roof geometries of single-span greenhouses at the winter solstice
(21 December), at latitude 51°N (Belgium), depending on the orientation (east-west or north-south) (adapted
from Nisen and Deltour, 1986).
µ
