Was wondering if people here had experience with these, or had them installed?
A friend of mine has one of these.
Seems like a great simple way to increase the temperature of the water stored in your home.
It will still need a temp boost to get to suitable shower or bathing levels, but if I remember my physics correctly, less energy will be needed to heat already warmed water.
A good idea, or one where the installation cost and material requirements sadly outweigh the potential gain from such a system?