[Greenbuilding] That Natural Feeling

[Corwyn]

On 1/10/2011 6:30 PM, Gennaro Brooks-Church wrote:
> This list, like most of the world, is roughly separated along two
> lines, those forward looking techies who value science and those
> backward looking naturalists who value tradition.
> In one camp you have the number crunching BTU types and in the other
> camp you have the adobe plaster types.

So which side are you putting me in?  As I do both, and generally 
recommend the naturalist side by showing the BTU number crunching.

Is it really necessary to make a two camps version of everything in 
life?  Much of our trouble comes from exactly that process.  Truth can 
be found in both camps, and the camps only keep it from being widely 
propagated.  'truth prison camps' one might say.

> In answer to Corwyn, my personal metric is the self invented Zero
> Brownstone Technique, which could be tweaked to any area but in my
> case is very specific to North Western townhouse construction. There
> is more on my site but is basically is zero waster during
> deconstruction, zero new materials during construction, and zero
> energy use in the final home. It is our goal. Right now the "right
> amount" of insulation based on this metric for a brownstone is about 6
> inches of polyiso, which by the way is a little more than what our PH
> building calls for that we are doing. That was a nice confirmation
> that my "hunch" was on the right track of the one of the best metrics
> out there right now.

Poly-isocyanurate foam board is 'naturalistic'?

Have you looked at the embodied energy of polyiso?  It is roughly 24 
TIMES more embodied energy than cellulose for the same R-value.

Put another way, 6 inches is around R-36.  So each square foot is losing 
3300 BTUs per heating season (5000 HDD), so the 25,700 BTUs that it took 
to make it represents 7.7 years of heat loss through the wall.  30 years 
of total energy costs = 125,000 BTUs.

Same thickness in cellulose, gives R-21.6 or 5600 BTUs per season, plus 
650 BTUs to make the stuff.  30 years of total energy costs = 167,000 
BTUs.  Pretty close.

Same R-value in cellulose gives 10 inches of thickness, losses of 3300 
BTUs, 1090 BTUs in embodied energy.  30 years total energy costs = 
100,000 BTUs.   A savings of 7.5 years worth of losses.

And yes, there is an even better solution in there somewhere that math 
would reveal.


Might I suggest that a guided tour of the BTU number crunchers 'truth 
prison camp', might lead you to a more natural solution?


Thank You Kindly,

Corwyn


-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
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