Radient heat from pipes of hot water running along the floor and
heated by a boiler and circulated by a pump is a very efficient way to
use your BTU dollars. Steam is not released into the air. You just
didn't see the boiler unit. It may have been removed if the system
was old and not functioning.

On Nov 9, 11:14 am, "Wendy7" wrote:
I often wonder about the use of steam to heat a g/h. I saw an old g/h a
few years ago
that had these large pipes going around under the benches. Nobody could tell
me how
they worked & the greenhouse was not in operation. (empty)
Of course one still has to have energy to make the hot water? Did they
not use
hot water pipes in the old days back in England?
Al, I think the energy costs are going to really escalate because there
are more & more
people using it! Water will be next.
Cheers Wendy