in-floor radiant and solar slab

["Bion D. Howard" <bdhoward@ix.netcom.com>]

Careful! 
~~~~~~~~ 
The "Kachadorian-style" -- nie "Air-Core" underfloor block heat storage
system needs to be designed with care.  Please consider _NOT_ using it as
the return air plenum to your HVAC system !!  

Why?  Because the sub-slab assembly will be under negative pressure, it may
draw in soil gases, and conditions could occur seasonally where
condensation might happen in the block leading to mold and mildew.

The above reasons are why I strongly recommend using the Air-Core system as
a hybrid de-stratification approach where solar warmed air is _supplied_ to
the block bed under slight positive pressure.  This also meets some
cardinal rules of solar -- "keep it simple" and "try not to mix auxiliary
heat into storage."

Air Core research paper (Adobe Acrobat required): 
  <http://www.energybuilder.com/pdf/asme-acs-tn.pdf>

Note: in paper there is discussion of a Santa Fe thermosyphon block bed
system designed by Scott Knoll, Ph.D who prepared the economics sections
and worked with Bob Jones and Doug Balcolm of Los Alamos passive solar
design guide fame...

Another good source is "National Concrete Masonry Assn." Tek Note 6-10.1984
on the Air Core Systems, which I hope is still available.
<http://www.ncma.org>

 <<< Bion Howard


Date: Sun, 25 Feb 2001 11:24:14 -0700
From: Ron Cline <rcline@swcp.com>
Subject: in-floor radiant and solar slab

I am working on a design for our new home in New Mexico, where it is
common to have single-story homes heated with in-floor hot water radiant
systems.  Does anyone know if such a system can be effectively
integrated with a Kachadorian-style solar slab set beneath the radiant
system slab?

Ron Cline
Albuquerque, New Mexico
=====


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