Flexible high grade stainless steel tube 316l or 304.
Copper pipe solar water heater.
And with fossil fuel dwindling there s a global move to look for alternative sources of energy.
These pages cover an experimental solar collector for heating water that uses aluminum heat absorbing fins and copper pipes for conveying the heat transfer fluid.
The key to good performance in this design is a good thermal connection between the aluminum fin and the copper pipe a lot of attention is given to providing this good thermal bond.