[Cob] energy modelling

[Janet Standeford]

Heads up everyone....This could be our big break!

Is anyone familiar with dynamic energy modeling using eQUEST, energy 10, 
or another dynamic energy modeling software?

Please understand that even though this is for adobe, the result is 
basically the same. The extra and longer straw in Cob just adds to the R 
value.

This is my communication with a Building Dept in Arizona and his 
communication with the person who did the modeling.

Per our phone conversation regarding the thermal performance of mass
walls:

Using dynamic energy modeling it is possible to compare the energy
performance of mass wall and non-mass wall homes.  In the past, we have
worked with the University of Arizona, College of Architecture to have
this comparison done.  The result is sometimes called the equivelent
R-value. In our climate here in Tucson, a 20" adobe wall home, with
properly sized and shaded south facing windows, will have the energy
performance of a home with R-19 insulated walls.

I recommend that you work with a person familiar with dynamic energy
modeling using eQUEST, energy 10, or another dynamic energy modeling
software and present these results to your building department.  Section
404 of the International Energy Conservation Code, titled "Simulated
Performance Alternative"  allows for energy modeling to show that you
are meeting the minimum requirements of the code.

Hope this helps!


Rich


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Rich:

Thermal mass simulation in steady-state models like RESCheck or COMcheck
are modeled using the equivalent R-value that yeilds the same results as
a case simulated with a dynamic energy simulation model.

In our case, we simulated a 20" adobe in the dynamic model and tried to
match the same results by increasing the initial R-11 value of batt
insulation of a non-thermal mass residence.  That  equivalent R-value
was found to be R-19.

i.e. to account for the advantage of thermal mass in comcheck or
rescheck you can simulate a 18"-20" rammed earth wall as R-19.  To
accurately represents the results the thermal mass MUST have properly
sized south-facing windows per square feet of exposed thermal mass.
But this is another calculation.

Hope that helps,

Nader