Setting U values for curtain walls?

[Anonymous]

How can I set the U value for a curtain wall made of glass?  I tried to go to Edit Type, but the option to edit the structure is disabled, how does one specify the material for a curtain wall?  Thanks for the help...

[Alaaeldin_Alsahli]

This is hard coded information so you can't change the U value on a curtain wall

 you have two options

Option1 create 2 design options 

the first one where you have your curtain wall on it 

and second design option you will take any wall duplicate it, name is as  (Curtain wall analytical), then create the material and the thickness that you want ( it wont look like a curtain wall but at least you could calculate the U value with it 

or

Option 2 is you go to (Analyze) Tab then (heating and cooling load)--- detail tab-- select a space then click on construction type and select the wall you want for exterior wall

[Anonymous]

Thanks for the response.

The problem with Option 2 is that not the entire wall is a curtain wall with glass.  The rooms are shops, with parts of the wall made of glass.

Is option 1 really my only hope?

[Alaaeldin_Alsahli]

Well then forget about you curtain wall and use Custom windows where you could play with U value

[Anonymous · Accepted solution]

For anyone who is wondering, I just spoke with Autodesk Support in Munich who suggested to click on the system panel element within the curtain wall via the Tab key and from there I can specify the material and the U value.  

[Alaaeldin_Alsahli]

this is good to know never thought of it but how are you going to calculate the energy

because there is a problem with the curtain wall when comes to energy analysis

it doesnt have the same surface area when exported to other software, where a simple window has a better data to be calculated 

read section 

5.6 Windows/Curtain Wall/Spandrel

5.6.3 Curtain Wall

http://sustainabilityworkshop.autodesk.com/sites/default/files/core-page-files/leveragingbimforenerg...

please keep me updated

[baselelhusseini]

Thank you!