Modeling curtain walls

[Alessandro Marzi]

Dear all,

I write you to submit the following questions.

1. I’m trying to model a curtain wall using THERM 7.5 (and WINDOW 7.5), but I need to clarify one point at first.

In the “THERM 7 / WINDOW 7 NFRC simulation manual”, pag. 217, is described how to model the curtain walls.

In my particular case, the façade is not continuos, but each glass cell is alternated to an opaque one, like in the docx attached.

How do you think is the correct procedure to deal these kind of configuration?

2. And how can I consider the opaque cell, considering that is not possible to model it in WINDOW?

 

Thank you very much in advance for your support.

Best regards

[yal...@gmail.com]

You would need to model multiple sections. For example the mullion with the glass-opaque and assign the u-factor tag to one half with the glazing and the other half to the frame with the opaque spandrel. You would then assign the glazing half of the u-factor tag to the center of glass to calculate the vision glazing u-value and the opaque frame portion to the center of spandrel u-value. This also is the same for the associated edge u-values derived in THERM.

The process for this type of curtain wall would be similar to the way outlined in ISO 15099 and analogous to ISO 12631 Single Assessment Method but with the edge of frame effects separated. Generally in the US the building codes require the substantiation of vision area and opaque areas separately and not as one aggregate value for the entire wall.

For your second questions you can build the opaque areas directly in THERM as the details require. This is a simpler way. If there is a preference you can also build up the opaque areas in Window by creating new layers and filling out the correct information.

Yalin