"Abe" wrote in message
Radiant heat floor systems use water from the boiler going into PEX
tubes over the concrete floor and under the finish floor to provide a
nice even gentle heat. It's great for basements because the floor
tends to be cold, and because the heat is gently rising from the
floor, you get nice even temperature throughout. The system takes up
about 1 inch of floor height, in addition to whatever finish floor you
put on top of the radiant system.

Is this good in a retro though? In new construction, the floor will be
insulated and the heating atop it. In the case of a retrofit, the heat will
also be trying to bring the rest of the earth up to temperature too won't
it? Unless, of course, insulation is part of the installation.