[Hap-users] Wall Assembly - Steel Stud Framing
MScott at nefisher.com
Fri Jan 25 10:27:52 PST 2013
Wow, that's kind of alarming to hear. I always assumed the U-value was
more important. I approximate the framing effect by first inputting the
ASHRAE 90.1 assembly for a given wall/roof type, then reduce the R-value
of the insulation (not the other values) until the U-value matches the
value listed in Table A3.3 for the given amount of continuous
insulation. Then I would add in the additional layers of construction
(like brick veneer, block, etc..) that are in the actual design but not
part of the basic ASHRAE tabulated assemblies.
N.E. Fisher & Associates, Inc.
329 East Second St, 2nd Flr
Boyertown, PA 19512
e: mscott at nefisher.com
From: hap-users-bounces at lists.onebuilding.org
[mailto:hap-users-bounces at lists.onebuilding.org] On Behalf Of Michael
Sent: Friday, January 25, 2013 1:01 PM
To: hap-users at lists.onebuilding.org
Subject: [Hap-users] Wall Assembly - Steel Stud Framing
The Wall Properties Input Screen calculates the overall R and U values
for a sandwich assembly however it doesn't have any way to factor in the
"framing effect" of wall studs which can have a significant effect on
average wall assembly R and U values.
When I queried Carrier, part of Craig's reply was for cooling design
loads and energy modeling, "...U-value is not important, what is
important is making sure the specific heat, density and weight of the
composite insulation/stud layer is correct. Those values are used in the
TFM equations not U-value."
Since this isn't as simple as inputting an overall U-Value from ASHRAE,
Has anyone come up with a way to effectively model steel stud framing
that would pass a DOE review?
Michael L. Hardy, PE, F.NSPE
Black Oak Engineering, Inc.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Hap-users