RE: [GBlist] Passive Solar/Thermal Mass Comparison

[Renewable News Network <rnn@rnn.com>]

you getting confused..

(see below)

On Mon, 26 Mar 2001, Halterman, Jon wrote:

> 
> > -----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) 

do you mean to say:

http://www.enertia.com  

> use a solid wood home as thermal mass, 

to some extent, everything within the "interior" of the house, that is,
the volume within the thermal envelop will have properties related
to thermal capacity effecting storage and temperature flux

> and design the
> home as a passive heat pump, drawing cool air from the basement through the
> sunspace.  

this does not describe what is commonly refered to as a "heat pump."

> 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.  

The Earth is 55 degrees F. and will absorb and waste, in effect, all the
temerature you give it.  The slab and basement and any contiguous living
space will then be 55 degrees and the will have stored nothing.

> They said it was to add a time lag into
> the system.  

Right, they want to keep the heat from escaping by conduction, from the
living space to the colder Earth, for as long as possible -- heat moves
to cold -- insulation slows that inevitable entropic process over time, or
until the sun comes up again, to recharge your space and heat store.

> I am just looking for further understanding of how insulation
> can be used in these types of systems.
> 
> Thanks again,
> 
> Jon 
> 


<RNN>


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