INSTALLATION – SOLAR COLLECTORS
36
INCLINATION OF SOLAR COLLECTORS
To help maximise system performance, solar collectors should be installed with an optimum inclination. This
is equal to 90% to 100% of the local latitude angle when collectors are oriented within 60° of true north or
true south, and between 10° and 20° when the collectors are oriented between 60° and 90° from the
optimum orientation.
Generally, improved summer performance is obtained from an angle of inclination less than the optimum
angle and improved winter performance is obtained by an angle of inclination greater than the optimum
angle. If the angle of inclination varies by 20° from the optimum angle, the solar collectors will receive about
10% less total annual solar radiation. The
latitude of some Australian cities
are listed on page 36.
However, the optimum inclination of solar collectors is not always practical or achievable. Solar collectors
may be installed at the roof angle for simplicity of installation and appearance, but must never be flat for a
Streamline direct water heater installation. Although the solar collectors can be installed with an inclination of
less than 10°, this is not advised.
The risks include:
the collector glass not 'self cleaning', leading to dirty collector glass reducing solar performance,
condensation on the underside of the glass taking longer to clear,
condensation droplets falling onto the absorber plate potentially causing discolouration.
The collector kit is suitable for installations with an inclination of up to 45°. Where the solar collectors are
installed at inclinations greater than 45°, a With Pitch frame is necessary. Refer to your local Solahart Dealer
for details.
A Variable Pitch frame can be installed to increase the angle of inclination of the collectors used in a
Streamline water heater installation. This type of frame should be used if the roof pitch either varies by more
than 20° from the optimum angle or is less than 10°.
The use of a Variable Pitch frame should be discussed with the system owner. If this option is neither
possible nor acceptable to the system owner, then the system owner needs to be made aware of,
understand and accept that increased boosting may be required to meet their hot water requirements.
CYCLONIC OR HIGH WIND AREAS
For an installation of solar collectors on a pitched roof in a cyclonic or high wind area, a suitable With Pitch
frame is required. Refer to your local Solahart Dealer for details.
The installation of these solar collectors on a suitable frame, subject to the frame‟s design criteria not being
exceeded:
is suitable for installation in geographic locations up to and within Wind Region D (With Pitch frame) or
up to and within Wind Region C (Variable Pitch frame), as defined in the Building Code of Australia,
Australian / New Zealand Standard AS/NZS 1170.2:2002 and the Australian Standard AS 4055-2006, or
equivalent location, and
provides an acceptable method of installation where it is necessary to satisfy the requirements of the
Building Code of Australia and AS/NZS 3500.4 Clause 6.5.3.4 for high wind areas, or equivalent
requirements.
LATITUDE OF SOME AUSTRALIAN CITIES
Adelaide
35°S
Cairns
17°S
Hobart
42°S
Port Hedland
20°S
Alice Springs
24°S
Canberra
35°S
Mildura
34°S
Rockhampton
24°S
Brisbane
27°S
Darwin
12°S
Melbourne
38°S
Sydney
34°S
Broken Hill
31°S
Geraldton
28°S
Perth
32°S
Townsville
19°S
