Cob: Re: Re: Re: Insulating in cold climates

[Bill Hunt]

> >generally you are
> > better off with most of your thermal mass (such as cob) inside of the
> > insulation, so it can store heat from passive solar, or any other heat
> > source.
Michael wrote: (snip)
> Do you have some equations for this? 

Sure, there are numerous computer programs that model passive solar design.
 I have some older formulas for doing hand calculations for passive solar
modeling, which I can dig out if you really want them.   The idea is that
the sun's warmth comes in through properly placed, south facing *windows*,
and is stored in thermal mass.  Direct gain thermal mass receives direct
sunlight, such as a concrete or earth floor, or any cob or masonry elements
that receive direct sunlight (inside the thermal envelope of the building).
 Indirect gain thermal mass is warmed by solar heated air in the building,
in contact with the mass that doesn't get direct sunlight.  
The heat is reradiated at night, and during cooler days. 


Severe cold climates like much of Canada generally do better with well
insulated houses.   Good insulation levels and good thermal detailing, as
well as south facing windows (in the northern hemisphere), and adequate
thermal mass, are needed for passive solar to be a significant benefit. 

Cheers- Bill