INSTALLATION – SOLAR COLLECTORS
28
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
PIPE LENGTHS
The solar hot and solar cold pipes between the solar storage tank and the solar collectors shall:
be of DN15 bendable grade or hard drawn copper tube.
Annealed or soft copper shall not be used.
have a continuous fall from the solar collectors to the solar storage tank of a minimum 5° (1 in 10 grade).
not exceed the maximum recommended lengths as specified in the table.
Maximum recommended total combined pipe length (solar cold + solar hot)
and number of 90° bends
Pipe Size
1 or 2 Collectors
3 Collectors
Pipe Length
90° Bends
Pipe Length
90° Bends
DN15
40 metres
20
30 metres
20
For each additional 90° bend, reduce the maximum total pipe length by 0.5 metres.
For each additional metre of pipe length, reduce the number of 90° bends by two.
Note: One 90° elbow is equal to two 90° bends.
Notes:
It is important to connect the solar cold and solar hot pipes to the correct connections at the solar
collector and at the solar storage tank.
The solar cold pipe connects to the bottom of the solar collectors and the solar hot pipe connects to the
top of the solar collectors diagonally opposite to the solar cold pipe connection.
The lowest corner of the solar collector installation, which is where the solar cold pipe connects to the
collector array, should be the corner closest to the solar storage tank. This will maximise the gradient for
the continuous fall of the solar cold pipe, by providing a shorter horizontal run of pipe work for the
vertical fall.
The hot sensor connection is at the top of the solar collector, directly above the solar cold inlet
connection.
Refer to
“Warning: Plumber – Be Aware”
on page 29.
It is essential for these requirements to be followed for the system to operate correctly and efficiently. Solar
pipe work which is oversized, or does not have the correct fall, or is too long can result in the drain back
system not operating effectively.