CONNECTIONS - PLUMBING
29
WARNING: Plumber – Be Aware:
·
The solar cold and hot pipes between the solar storage tank and the
solar collectors
MUST BE
of copper and fully insulated with Armaflex
insulation or similar (minimum thickness 10 mm).
·
The insulation must be weatherproof if exposed and
fitted up to the
connections on both the solar collectors and the storage tank
, as
very high temperature water can flow from the solar collectors to the
solar storage tank under certain conditions. The insulation will also offer
corrosion protection to a metal roof against water runoff over the copper
pipe.
·
Plastic pipe
MUST NOT
be used, as it will not withstand the temperature
of the water generated by the solar collectors under stagnation
conditions. The solar collectors can generate extremely high water
temperatures, up to 150
°
C
, and high water pressure of 1000 kPa. Plastic
pipe cannot withstand these temperatures and pressures, and
MUST
NOT
be used. Failure of plastic pipe can lead to the release of high
temperature water and cause severe water damage and flooding.
·
There
must be a continuous fall
in the pipe work between the solar
collectors and storage tank. The highest point of the solar cold pipe and
solar hot pipe must be where they connect to the solar collectors, to
avoid the possibility of air locks occurring in the system.
PIPE LENGTHS
The maximum recommended combined length of the solar cold and solar hot pipes
with bends is:
Maximum recommended pipe length and number of 90
°
bends*
1 or 2 Collectors
3 Collectors
4 Collectors
Pipe
Size
Pipe
Length
90
°
Bends
Pipe
Length
90
°
Bends
Pipe
Length
90
°
Bends
DN15
40 metres
20
30 metres
20
NA
NA
DN18
60 metres
20
40 metres
20
32 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.