[Bldg-sim] LEED modeling / air leakage / R-values

[Paul Grahovac]

I am not a modeler, but I've worked a bit with the TRANE Trace demo
software a few years ago.

 

I've forgotten how to maneuver within it, so I was hoping someone might
comment on this question.

 

The software provided an air leakage rate for whatever wall assembly is
entered into the model.

 

I know from previous posts and responses that you do not change the air
leakage rate to account for any air barrier system that is to be
installed.  I also know that if you do apply an air barrier leakage
rate, the model is very sensitive to it, and the model produces
significant energy savings because of it.

 

And, it's my understanding the R-value rating of the insulation is used
despite that the rating is based on more or less zero air flow.

 

So, I'm wondering if the models, seeing both zero-air-flow insulation
and un-moderated leakage rates, ignore one or the other or somehow
produce a modulated result that reflects reduced wall assembly R-value
from air leakage through it.

 

Paul Grahovac, LEED AP

Product Manager 

R-GUARD Air & Water-Resistive Barrier 

PROSOCO, Inc.

3741 Greenway Circle

Lawrence, Kansas  66046

(785) 830-7355

(888) 376-3417 fax

pgrahovac at prosoco.com

web site  http://www.prosoco.com/

 

 

 

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