Hello 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 1.4.1 Tables “Opaque Building Envelope Constructions” requirement, 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,
Morteza
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
August 23, 2013 - 3:42 pm
Find the closest one and extrapolate. Be sure to read the text as the tables include assumptions about the construction. There is a table for block walls with steel framing and continuous insulation. Compare the assumed exterior finish to the one you have to see if there needs to be an adjustment.