Window u-values and SHGC

arl · Posts: 3

I had other simulation problems in the results. I talked to Andy and to other specialist to include the right values.

So thanks to all, and specially to Andy for the support.

regards, from sunny barcelona.

Asier

juncalixihan · Posts: 57

Hi!

It seems effort is being made to closely model actual glazing systems in DB. Thanks for your efforts in this.

I have done a "trial and error" on the glazing layers on a project even before I read this thread. It works ok for me for glazing comparison purposes. However, in my experience I had to compromize some properties, say Direct Solar Transmission and glass surface emissivities, just to get the manufacturer whole glazing SHGC and U-value in the Calculated tab. This may be because the particular glazing system has a PVB interlayer (see attached).

In light of making DB even more flexible, it is possible to include a lamination in the layer options aside from gas fills? Say in future DB versions? Don't know yet how much contibution will the 1.5mm lamination give thermally/optically but if it does have significant effect then maybe it can be added to DB? Right now we don't have much alloted time in our projects to run Windows5 for import into DB.

What do you think of this?

Thanks in advance!
Jun

hanuman · Posts: 13

hi

still having issues interpreting the windows.

The window NRFC data we have for a 3mm sliding window:
1) whole window U value (i'm assuming this includes the frame) 6.5
2) shgc whole window 0.77
3) Tvw - visible light transmittance whole window 0.79
4) Air inf 0.5

Could someone please describe how to enter these values into designbuilder.

bhandari · Posts: 120

Hi Jun and Hanuman,

The best way in this case is to use WINDOW5. As Andy indicated soon DB will have the option of reading fenestration products directly from WINDOW5/6 but in the meantime the following work around can be tried:

-In your case, it looks like it is just a single clear glass with AL frame. You should be able to get the desired U/SHGC/VT by selecting single clear glass with AL frame in DB (Frame width-2 inches). Please note the calculated value in glazing screen in DB includes only center of glazing value (excluding frame)..

- Laminated glass will have significant impact on SHGC/VT. For example, the SHGC of 6 mm clear glass is 0.86 while the laminate with 3 mm glass-30 mil (0.76 mm)interlayer-3mm glass would have SHGC of 0.66. Currently, we need to use OPTICS to create laminates (WINDOW 5 cannot create laminates), so I think the laminated creation is unlikely to be included in DB in near future. DB could include some common laminates in database. For now, the only way to use laminate properties is to create laminate in OPTICS (or if you have measured data for the laminate)and create a new glass in DB with the properties of laminated glass.

I hope it helps..

regards,

Mahabir

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