RE: [GBlist] Passive Solar/Thermal Mass Comparison

["Halterman, Jon" <Jon_Halterman@compuware.com>]

> -----Original Message-----
> From: Renewable News Network [mailto:rnn@rnn.com]
> Sent: Monday, March 26, 2001 2:28 PM
> To: Halterman, Jon
> Cc: Ross M. Donald 1-781-453-9668; Greenbuilding (E-mail)
> Subject: Re: [GBlist] Passive Solar/Thermal Mass Comparison
>
> On Mon, 26 Mar 2001, Halterman, Jon wrote:
> 
> > I was wondering if someone could direct me to a good resource on a
> > comparison materials used for thermal mass.  I have heard 
> some discussion on
> 
> concrete has a thermal capacity of .21-.24 (?) Btus/degree F./Pound
> water has a thermal capacity of 1.00 Btus/degree F./Pound
> 
> salt water mixtures have latent heat of melting in the phase changing
> ranges, which could be room temperature, but will require more research
> and design work on your part - look for a packaged product w/phase
> changing material in a pouch or tube, to be installed in a rack or
> ceiling tile system.
> 
> > this but would be interested in learning which materials have the best
> > thermal mass properties and how others compare with them.
> 
> you've basically got water and masonry

I assume stone falls into the same category as masonry?  What about cultured
stone?  Where is wood in all of this?

> > Also, it seems that the use of insulation is counter productive in
> > conjunction with a thermal mass.  One person has suggested 
> that the use of
> > insulation just increases the time lag associated with a 
> thermal mass.  I
> > would be interested in any thoughts you have on this.
> 
> I'd suggest not trying to store your solar heat gain in a high mass
> glazed-over exterior wall -- (where is the site?) -- what do 
> does it do
> you there - you're only going to lose it through the front of the
> collector area.  Instead, direct the light or move the heat 
> directly to
> the point of use or, secondarily, into a storage component, 
> designed to
> take and hold heat to be drawn down later.

I knew that I would have to explain this better.  The thermal mass used is
for a passive cooling system.  The homes designed by Enertia
(wwww.enertia.com) use a solid wood home as thermal mass, and design the
home as a passive heat pump, drawing cool air from the basement through the
sunspace.  The insulation I was refering to was placed between the basement
slab and the earth.  I questioned this because I assumed the whole point of
the process was to use the cool air of the earth as a part of the process
and not isolate the system from it.  They said it was to add a time lag into
the system.  I am just looking for further understanding of how insulation
can be used in these types of systems.

Thanks again,

Jon 

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