HTP FP-40SC - Manual (Page 14)

14
H. COLLECTOR ANGLE, PLANE, AND DIRECTION
1. COLLECTOR DIRECTION
The collector should face the equator. In the
northern hemisphere, this is due south, and in
the southern hemisphere, due north. Facing the
collector in the correct direction and angle is
important to ensure optimal heat output. A
deviation of up to 15
o
from due south is
acceptable, and will have minimal effect on heat
output.
Figure 2: Suggested placement of solar collectors
NOTE: In Figure 2, B, C, and D orientations (horizontal or landscape) are not recommended for drain
back systems.
2. COLLECTOR ANGLE (TILT)
It is common for collectors to be installed at an angle that corresponds to the installation latitude. While
adhering to this guideline, an angle of latitude +/- 10
o
is acceptable, and will not greatly reduce solar
output. The solar collector should be installed at an angle of between 20 – 80
o
to ensure optimal
operation.
For year-round domestic hot water, the collector should be tilted to an angle of equal to the latitude of the
installation site. Add 15
o
to the latitude to optimize for winter performance (space heating). Subtract 15
o
from the latitude to optimize for summer performance (pool heating).
Given the formula above, a solar collector installed at 30
o
N latitude should face due south at an angle of
45
o
for wintertime advantage, and 15
o
for summertime heating.
Preventing Overheating
To reduce summer heat output, angle the collector for optimal winter absorption. This is achieved by
installing the collector at an angle of around 15
o
above the latitude angle (e.g. 45
o
at 30
o
N latitude). This
angle corresponds closely to the angle of the sun in the sky during the winter months, thus maximizing
winter output. Conversely, during the summer when the sun is high in the sky, the relative collector
surface area exposed to sunlight is reduced, cutting overall heat production considerably (by about 15%).
This option is ideal for installations where solar thermal is being used for space heating.
3. COLLECTOR PLANE (HORIZONTAL OR VERTICAL)
The collector could be installed vertically, but may be installed at an angle, such as sideways on a pitched
roof. It is not recommended to install a drain back system in the horizontal or landscape style. In vertical
installations, collectors may be installed level, or with ¼” pitch towards the return port. See more detail in
Part 2, Section D, Number 3.