What piping is recommended between the solar panels and the hot water tank?
Due to the low stagnation temperature of DualSun panels (80°C), we recommend using multi-layer piping for the solar circuit. Multi-layer piping allows to reduce costs. Nonetheless, it is important to well-insulate the pipes and the seals and protect them from UV radiation by using insulation with an anti-UV surface.
The use of copper and stainless steel piping is of course also possible, though copper is expensive and difficult to install, and the corrugated surface of stainless steel pipes can trap air in the circuit.