[Cob] Radiant heat floors

[hms.mommy at juno.com]

> My own choice was to lay dry clay pipe in gravel overlaid with tile in
   a clay mortar...then allow heat to circulate into the pipe from a
   lower level green house...this is to be a passive solar or wood fired
   system.  taking the subterranean 52+/- degrees and heating it.  The
   smoke from the fire would be exhausted out of the cellar or
   greenhouse, using a masonry stove for greatest heat efficiency and the
   heated air from the confined area would heat the level above thru
   vents into the floor pipes... No smoke would ever be in the house.<

So Cat, are you saying that there would be no direct contact between the
air heated by the fire and the air in the clay pipes?  Is that what you
mean when you say there would be no smoke in the house?  Or are you
saying that the smoke and hot air would travel through the clay pipes
under the floor and out of the house, and that's why no smoke would be in
the house?  

Any thoughts about provisions for cleaning the pipes?

Carrie