Rheem 511161 Owner's Manual And Installation Instructions page 38

INSTALLATION – SOLAR COLLECTOR(S)
A CSA2612 or LCS or NPT200 solar collector(s) may be installed up to 90° from the optimum orientation when
installed as part of this system, however solar system performance will be reduced. 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.
The total solar radiation received by solar collectors will reduce by approximately 4% to 5% when facing 45°
from the optimum orientation and approximately 10% to 15% when facing 90° from the optimum orientation.
Where the collectors can be installed at a similar angle either east or west of the optimal orientation, then the
hot water load and usage pattern may need to be considered. If the majority of hot water usage is before
2:00 PM favour an easterly bias. If the majority of hot water usage is after 2:00 PM favour a westerly bias.
Note: Always check for true north or true south using a compass or other suitable device.
In Victoria, an approved 511161 tank system with 1 x CSA2612 solar collector installed within the Regulation
Compliance Zone achieves compliance to new home legislation for water heating. Outside of the compliance
zone 2 x LCS solar collectors should be used to achieve compliance.
In areas other than Victoria, 2 x LCS solar collectors should not be installed with this system.
INCLINATION OF SOLAR COLLECTOR
To help maximise system performance, the solar collector should be installed with an optimum inclination. This
is equal to 90% to 100% of the local latitude angle when the collector is oriented within 60° of true north or true
south, and generally between 10° and 20° when the collector is 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 collector will receive about 10% less total
annual solar radiation. The
AS/NZS 3500.4 states that solar collectors shall be installed at an angle within 20° of the local latitude angle.
However, the optimum inclination of the solar collector is not always practical or achievable. The solar collector
may be installed at the roof angle for simplicity of installation and appearance, but must never be flat for a
pumped solar water heater installation. Although the solar collectors can be installed with an inclination of less
than 10° from the horizontal, this is not advised.
The risks include:

the collector glass not 'self-cleaning', leading to dirty collector glass reducing solar performance, and

condensation on the underside of the glass taking longer to clear, and

condensation droplets falling onto the absorber plate potentially causing discolouration.
The collector kit is suitable for installations with an inclination of up to 45°.
A Variable Pitch frame can be installed to increase the angle of inclination of the collector used in a pumped
solar 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 if the roof pitch 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, it may be possible for an additional solar collector to be installed or to
install selective surface collectors in lieu of non-selective surface collectors to help make up for the reduction
in solar performance compared to the optimum inclination. Each option should be discussed with the system
owner.
If these options are 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.
latitude of some Australian cities are listed on page 39.
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