thomas rubino wrote:As to building underground , yes, that is done but... you must insulate from the earth or all but the radiant heat from your barrel will be trying to heat the ground surrounding your rmh.
Brian Cady wrote:I like the floor heating concept. It reminds me of a Korean Ondol: https://en.wikipedia.org/wiki/Ondol
There's a concept proven over thousands of years.
"How much heat would actually be lost straight down through what (at that depth) is basically hard packed caliche and/or red clay? (Floor is about an inch of sand over a varying amount of caliche, then hard red clay. ..."
I read in an underground house book about northern USA ground temp.s averaging about 55 degrees F. Maybe there undergrond temps would average 60? There's is r-factor information on heat conductance in soils, so this heat loss downward is an answerable question.
"--- they were still hitting stacked limestone walls well past 4 feet. Makes me wonder if there was once a root cellar or cistern with a wood floor at ground level.)" Wow, I'm surprised at how substantial a footing was built.
allen lumley wrote:Joe : I am sending you a link to a different build because you could have problems getting an in ground system like you are thinking of to ''Draft'' when cold !
You would ordinarily have an inspection and clean out ''T'' located where your horizontal pipe goes vertical, but in your situation that part would be in the floor
and lighting a fire there to 'kickstart' you draft would be a difficult build, so instead this system is designed to divert the heat from after your barrel to your
chimney, then when your chimney is warm you flip the damper to let the hot exhaust gases flow through the horizontal piping !
allen lumley wrote:To heat he total sq ft you have, a 6'' system is more than adequate, however even with a good exterior vertical chimney to help your draft with a 6'' system 30 feet of horizontal run is all that we can comfortably tell you you are going to be able to count on ! However, that 30' loses 5 feet for every 90º Elbow in your system, And -if we have to come up out of the ground with a 90º elbow, turn 90º to go out through a window and then turn up with a inspection / clean out ''T", we have used up the better part of 15' and we have no pipe in the ground yet.
allen lumley wrote:The RMH community also has been setting on its Laurels for years, but lately there has been a gather of wizards and great things are being spoken of as tho
they were already common. Our goal right now is to help you build your first RMH, after that You will be one of the Permies Rocketeers that are telling newbies
exactly how you did it, and probably how you are going to build your next one !