INSTALLATION – SOLAR COLLECTORS
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 generally between 10° and 20° when the collectors are oriented between 60° and 90° from the
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 27.
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 less than 10° from
the horizontal for a closed circuit drain back system.
The solar collectors, when installed with the supplied mounting system, are 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. Contact Rheem or your local Rheem Solar Water Heater Distributor for details.
A Variable Pitch frame can be installed to increase the angle of inclination of the solar collectors used in a
solar pumped water heater installation. This type of frame should be used if the roof pitch is less than 10° or
varies by more than 20° below the optimum angle. Contact Rheem or your local Rheem Solar Water Heater
Distributor for details.
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 solar system performance will be reduced and 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. Contact Rheem or your local Rheem Solar Water Heater Distributor for details.
The installation of these solar collectors on a suitable frame, subject to the frame’s design criteria not being
may be 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 Standard AS 4055 and the Australian / New Zealand Standard AS/NZS 1170.2, or equivalent
may provide an acceptable method of installation where it is necessary to satisfy the requirements of the
Building Code of Australia and Australian / New Zealand Standard AS/NZS 3500.4:2003 for high wind
areas, or equivalent requirements.
LATITUDE OF SOME AUSTRALIAN CITIES