Solahart 151J, Owner'S Manual

Page: 21 / 60

INSTALLATION INSTRUCTIONS - ALL MODELS
21
Orientation of Solar Collectors
To help maximise system performance, solar collectors should be installed with an optimum orientation facing true north
(in the southern hemisphere) or true south (in the northern hemisphere). Always check for true north or true south using a
compass or other suitable device.
The solar performance of a system reduces as the orientation of the collectors moves away from the optimum orientation,
resulting in the need for increased boosting to supply the same hot water load. Solar collectors facing up to 45° from the
optimum orientation will receive about 4% to 5% less total solar radiation.
However, the optimum orientation of solar collectors is not always practical or achievable. Solar collectors may be
installed up to 90° from the optimum orientation. Where the orientation is greater than 60° from the optimum, either an
additional solar collector or selective surface collectors in lieu of non-selective surface collectors should be installed to
make up for the reduction in solar performance. Note, these options may not be required in either warmer latitudes where
sufficient solar performance can still be achieved, or where over-performance of such a system is likely or has proven to
occur. Each of these options should be discussed with the system owner. If neither of these options is possible nor suitable,
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.
If it is not possible to face the equator, the decision of either an EASTERLY or WESTERLY bias must be made. If the
majority of hot water usage is before 2 p.m. favour an EASTERLY bias. If the majority of hot water usage is after 2 p.m.
favour a WESTERLY bias.
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° if 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.
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° for a thermosiphon
water heater installation.
A Variable-Pitch frame can be installed to increase the angle of
inclination of a thermosiphon water heater and should be used if the roof
pitch either is less than 10° or varies by more than 20° from the optimum
angle. At pitches greater than 30
° , the system must be installed mounted
on a With Pitch frame. A suitable frame is available from your local
Solahart Dealer.
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.
FROST / FREEZE PROTECTION
An Open Circuit system does not have freeze protection and is not suitable for installation in areas prone to freeze
conditions. Freeze conditions occur below 5°C (41°F). This system has NO WARRANTY for freeze damage. In areas that
are prone to frost / freezing, a Closed Circuit system should be used.
Solahart recommends using a minimum of one complete 4.5 litre bottle of ‘Hartgard’ in each system (or a minimum
concentration of 20% in large capacity systems) as standard where ambient temperatures do not fall below 0°C.
Alternatively, the concentration of ‘Hartgard’ in the closed circuit should be determined to suit the minimum ambient
temperature that the system will be exposed to. The Freezing Point temperature of varying concentrations of ‘Hartgard’
solution in water is given below:
20% Hartgard by volume -7°C 18°F 40% Hartgard by volume -22°C -8°F
30% Hartgard by volume -13°C 7°F 50% Hartgard by volume -34°C -29°F
If the system is to be installed in an area where the temperature falls below -34°C (-29°F), please contact your local
Solahart dealer for advice.