Rheem Water Heater - Manual (Page 35)

INSTALLATION – SOLAR COLLECTORS
35
WARNING: Plumber – Be Aware
• The solar hot and solar cold pipes between the solar storage tank and
the solar collectors MUST BE of copper and fully insulated with closed
cell polymer insulation or similar (minimum thickness 13 mm). Thicker
insulation may be required to comply with the requirements of
AS/NZS 3500.4. The insulation must be weatherproof and UV resistant
if exposed. All compression fittings must use brass or copper olives.
The insulation will offer corrosion protection to a metal roof against
water runoff over the copper pipe, assist in avoiding accidental contact
with the solar pipe work and also reduce pipe heat losses.
• The insulation must be fitted up to the connections on both the solar
collectors and the solar storage tank, as very high temperature
closed circuit fluid can flow from the solar collectors to the solar storage
tank under certain conditions.
• Plastic pipe MUST NOT be used, as it will not withstand the
temperature of the closed circuit fluid generated by the solar collectors
under stagnation conditions. The solar collectors can generate
extremely high closed circuit fluid temperatures up to 150
°C. Plastic
pipe cannot withstand these temperatures and MUST NOT be used.
Failure of plastic pipe can lead to the release of high temperature
closed circuit fluid and cause severe water damage and flooding.
• There must be a continuous fall in the pipe work between the solar
collectors and solar storage tank for efficient and effective drain back to
occur. The highest point of the solar cold pipe and solar hot pipe must
be where they connect to the solar collectors.