I am underwhelmed
You’d get more heat from that coil by laying it on the roof, IMO.
Where’s the saving in something that costs so much? 
Doesn’t the gov’t need that copper for penny production?
John Kogel
www.allsafehome.ca
Probably took more energy to manufacture and install than it will save in a serviceable lifetime. Good to sell to yuppies to make them feel good about themselves though.
From the research document you save about $100 per year in utilities but the pipe costs about $1200 so 12 years before you start to get a payback…bad investment!