These are designed for low temperatures with enough water flow to prevent any great temperature rise, thus making them very efficient and not requiring housing in a box with glazing etc.
The proposed use for domestic water heating is fraught with problems, I have yet to see one that doesnt have the odd minor leak, as they only have push fit tubing to plastic header fittings. The other issue is the much higher sustained temperatures and softening of the plastic fittings, while the HDPE tubes themselves are reasonable resistant to heat, the other bits are not.
If you made copper headers with push fit then clamped leak proof fittings then they may work, the suggestion of heat exchanger is a good idea. There would be lesser requirement to prevent frost damage as the tubes can expand on freezing. The tubes cannot handle any great pressure, normally they lie near flat, so you may find a greater tendency for leaks as the temperature rises and tubes soften and expand.
Cheers
Mike
|