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<div class="moz-cite-prefix">I think actually thermal diffusivity is
the more relevant parameter.<br>
We are expecting to hit 5C (41F) for the first time since
Halloween tomorrow, I am not sure thermal mass is so wonderful
buried in the wall in this climate.<br>
There are several ways that HD Day is calculated. For Code in
Canada it's based on the mean daily temperature so I suppose that
might be seen as "hourly computed", but is it <i>always</i>
lower?<br>
<br>
<br>
<br>
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<blockquote cite="mid:51781B00.7080508@greenfret.com" type="cite">On
4/24/2013 12:39 PM, RT wrote:
<br>
<blockquote type="cite">But that doesn't stop me from having an
opinion.
<br>
</blockquote>
Color me shocked. :-)
<br>
<blockquote type="cite">I also know that the usefulness of a
material as beneficial thermal mass is directly proportional to
its density.
<br>
</blockquote>
Not quite. It is proportional to its density times its specific
heat (which can vary by material). But the point is well taken.
<br>
<blockquote type="cite">I can't help but wonder if it might not be
better (ie lower cost, lower embodied-energy, better thermal
performance) to simply use a run-off-the-mill, regular density
masonry exposed to the interior and outsulate it with a good
insulation material ?
<br>
</blockquote>
Probably.
<br>
<br>
...<br>
</blockquote>
<br>
<blockquote cite="mid:51781B00.7080508@greenfret.com" type="cite">
I don't see how 'time to heat' can possibly increase annual demand
in a more or less continuously occupied building (intermittent is
another thing altogether, of course). Maintaining 68°F 24/365 is
just a matter of heat loss * heating degree days. High mass means
that one is computing that on daily or even multi-day average HDD,
as opposed to hourly computed HDD. Which is<i> always</i> going
to be lower.<br>
<br>
Thank You Kindly,<br>
<br>
Corwyn
</blockquote>
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