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[EnergyPlus_Support] Pane properties - ASHRAE 90.1

Hi all,
I am currently trying to model a baseline building according to the ASHRAE 90.1 Standard, using Energy Plus and I have the following issues:
1. In Table 5.5.1 (ASHRAE Standard 90.1) it is mentioned a U value of 6.93W/m2K for a vertical window and 11.24W/m2K (or 7.72W/m2K) for a skylight. These U values seem really high and (in my opinion) rather unreasonable since it will lead to negative resistances. What is your opinion in this? Did I miss something?
2. In my understanding, when one inserts a simple window model in E+ with a Uvalue of 6.93W/m2K and a SHGC of 0.25, E+ follows a procedure (as described in the Engineering Reference, page 177) in order to define the properties of the equivalent pane. I had two issues: (a) when calculating the layer solar reflectances (according to the equations givven by the manual) I got different values than the ones described by the .eio file (for the U and gvalues mentioned above); (b) After running my model, the pane Uvalue of .eio output file was 5.75 instead of 6.93W/m2K  (inner and outer emittances of 0.834); does that mean that E+ will not increase the emittances more than 0.834 and that can't get higher U values when specifying a simple window model (in the Engineering Reference it mentions that a max Uvalue would be 7W/m2K)
3. For a glass with the properties suggested by the standard, E+ outputs a pane with SHGC of 0.25, and Tsol of 0.11; isn't the Tsol rather low (less than the half)?
Any help is highly appreciated
Thanks in advance
Harris Poirazis 




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