[Equest-users] U-factor for existing masonry wall

Byron Burns B.Burns at ha-inc.com
Mon Aug 26 06:45:57 PDT 2013

Hello Morteza,


Here is a catalog of tested wall masonry assemblies, you may be able to
find most of your assembly in it. I do not guarantee the accuracy of the
data nor the testing procedures used to obtain it as you will see they
did not mention the use of any ASTMs. However, it may be helpful
calibration data if you need to build an isothermal or 2-D model of your
wall assembly.  


Also ASHRAE  90.1-2007 Section A9 lists the procedures to determine
assemblies that are not listed in the tables of Appendix A.  Reading
between the lines a little you can calculate the R-Value for each layer
using the appropriate calculation method for that type of wall.  For
example you can use the test data for the exterior CMU wall layers and
do a parallel path calculation for the continuous insulation and cavity
layers, sum the results for the assembly R-Value.


Hope that helps,


Byron D. Burns, EIT, BEMP 
Energy Analyst/ Modeler 

H&A Architects & Engineers | www.ha-inc.com <http://www.ha-inc.com>  

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Morteza
Sent: Friday, August 23, 2013 2:09 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] U-factor for existing masonry wall


Helow all,

In this LEED-CS project, the existing masonry wall was changed to the
following configuration (from outside to inside):

 - glass-fiber-reinforced concrete panels [TAKTL] on galvanized steel
furring channels

- existing 8" masonry wall

- 3" polyisocyanurate insulation (R-18)

- 1/2" air space

- 3-5/8" metal studs without thermal insulation

- 5/8" gypsum wall board

Per ASHRAE 1.4 Tables "Opaque Building Envelope Constructions"
requirnment, proposed construction assembly U-factor should be
as-designed and consistent with Appendix A of ASHRAE 90.1. I cant fined
any table in Appendix A to match this configuration. How should I select
the U-factor for this wall?

Thank you so much for your help,





-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20130826/7cf33fa3/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: CMU- Thermal Catalog Phase I.pdf
Type: application/octet-stream
Size: 2440006 bytes
Desc: CMU- Thermal Catalog Phase I.pdf
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20130826/7cf33fa3/attachment-0002.obj>

More information about the Equest-users mailing list