I am still learning about all "green" ways or other ways to install stuff, so I have a question for you'll.
I have always done radiant heat with a boiler as the source ( Long Island Thing, I guess )
I was just on youtube and found this
He is using an on demand water heater, Think they make one big enough for a 12 zone radiant heat zone system running 18,000 feet of pex?
Has anyone here ever used or installed a system like this, It's got me curious and wondering how many zones you could do
Please let me know, I am not an radiant expert but like to learn and usually we use lots of slant fin baseboard.