Rheem 12104793 Installation Instructions Manual page 13

PIPE LENGTHS
The solar hot and solar cold pipes between the solar storage tank and the solar
collectors shall:

be of 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.
Horizontal runs of pipe work are acceptable and may be installed as part of
an open circuit system.
Care must be taken to ensure the pipe work maintains a continuous fall or
horizontal runs over the life of the installation. Pipe work should be fixed at
regular intervals to assist in maintaining this requirement.

not exceed the maximum recommended combined lengths as specified in
the table.
Maximum recommended total combined pipe length (solar hot + solar cold)
Pipe Size
Pipe Length
DN15 40 metres
DN20
For each additional 90° bend, reduce the maximum total pipe length by 0.5 m.
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.
NR – not recommended, NA – not available
Notes:

It is important to connect the solar hot and solar cold pipes to the correct
connections at the solar collectors and at the solar storage tank.

The solar cold pipe connects to the bottom of the solar collector array and
may connect to either the left or right hand side. The solar hot pipe must
connect to the top of the solar collector array diagonally opposite to the solar
cold pipe connection. The solar hot outlet connection is to be the highest
point of the system.

The hot sensor connection is at the solar hot outlet where the solar hot pipe
connects to the solar collector for this open circuit system.

"Warning: Plumber – Be Aware"
Refer to
It is essential for these requirements to be followed for the system to operate
correctly and efficiently. Solar pipe work which is oversized, or is too long, or
does not have a continuous fall can result in a reduction in performance or the
system not operating effectively.
and number of 90° bends
1 or 2 Collectors
90° Bends
20
NR NR
INSTALLATION – SOLAR COLLECTORS
Pipe Length
30 metres
40 metres
on page 14.
13
3 Collectors
90° Bends
20
20