Need some guidance with Steel Stud wall panels

[Roger Taylor]

Hi guys,

Ayyuba helped me previously and I think I'm following directions correctly, but I would like some reassurance that I am doing this correctly.

I attached both an excel and PDF in case you can't open the excel file.   It explains the steps I followed.  

I also include the THERM files in attached zip file

Thank you for your help.  Looking forward to your guidance.

Roger Taylor

RTa...@DGDallas.com

214-607-2537

[archi...@gmail.com]

Hi Roger.

Reading the explanation in your pdf file I think your steps are correct, but I would cut their number to only 2 to avoid the possibility of introducing undesired errors:

Step 1. Calculation of equivalent thermal conductivity of the perforated web
                    1a   Total thermal resistance with Therm Rtot
                    1b   R = Rtot - Rsi - Rse
                    1c   Equivalent Thermal conductivity Leq = s / R
Step 2. Calculation of the wall thermal transmittance and resistance with Therm using the Leq above for the perforated web.

I attach three Therm models: one for the perforated web, one for the panel, one for the wall.
Results differ slightly from yours because I made some corrections to the geometry of your therm model to make it consistent with the dimensions in your pdf file (page 2) and with panel's data sheet and I used a more appropriate thermal conductivity value for galvanized steel (L=62 W/mK):

Perforated web equivalent thermal conductivity Leq = 28.57 W/mK  (Rtot with Therm = 0.2139 m2K/W, R = Rtot - Rsi - Rse = 0.2139 - 0.1304 - 0.0793 = 0.0042 m2K/W, Leq = s / R = 0.12 m / 0.0042 m2K/W =  28.57 W/mK)
Panel total thermal resistance with Therm = 2.7033 m2K/W (15.3498 in American units)

Panel equivalent thermal conductivity Leq = 0.060 W/mK (R = Rtot - Rsi - Rse = 2.7033 - 0.1304 - 0.0793 = 2.4939 m2K/W, Leq = s / R = 0.15 m / 2.4936 m"K/W = 0.0601 W/mK)

Wall thermal transmittance  U = 0.249 W/m2K (0.0439 in America units)
Wall thermal resistance R = 4.016 m2K/W (22.8033 in A.u.)

Ciao

Fabrizio