LOW-E glass and double glaze window

Replies to This Discussion

Permalink Reply by Theodoros Galanos on November 29, 2015 at 5:36am

Hi Iman,

The easiest way I can think of is to create your glazing system with the LBNL Software and then import the gbxml file into Honeybee.

In the official site of LBNL there are instructions on which options you enable in order to produce an xml file. After that the software is quite straightforward. In the glazing system tab, you select the number of layers, type of glass (out of thousands in the available library), type of gap, etc.

Once you are done you just press the Calculate button and the file is produced. Using the available Honeybee component you can import it into your model.

It is also possible to assign your glass properties manually in Honeybee. That method is a bit more difficult because you would need detailed info. You can find that perhaps from the supplier (rarely the have reflectances though) or, again, you can extract it from LBNL Windows (bypassing in a way the creation of the xml file).

I am not aware if there is any impact on the results between the actual xml file and using values (as it would be the case I guess when using no mass wall materials in E+). Perhaps someone more experienced can answer that one.

Hope this is helpful. Good luck!

Kind regards,

Theodore.

Permalink Reply by Iman Khayat on November 29, 2015 at 5:54am

thank you Theodore,so i have to create my material with honeybee radiance BSDF material. i hope it will work.thanks again.

Permalink Reply by Mostapha Sadeghipour Roudsari on November 29, 2015 at 7:24am

Also check this discussion on unmethours.com: https://unmethours.com/question/1037/converting-transmittance-to-tr...

Permalink Reply by Theodoros Galanos on November 29, 2015 at 5:20pm

Very interesting discussion Mostapha thanks!

I have a question. Is the BDSF file of Windows representing multiple layers correctly? (I'm guessing but to be sure). Or is this need for actual multiple layers a geometric need? (do I physically have to draw them in order to get correct results, much like we would do when rendering IGU glass?).

Kind regards,

Theodore.

Permalink Reply by Mostapha Sadeghipour Roudsari on November 30, 2015 at 7:41pm

Hi Theodore, Once you have BSDF then you can apply it to a single surface but in case you want to make sure that the thickness will be modeled correctly then you may use two surfaces. Check slides 43 and 44 from this presentation by Andy: http://www.radiance-online.org/community/workshops/2014-london/pres...

Permalink Reply by Iman Khayat on November 29, 2015 at 8:45am

thank you very much Mostapha.

Permalink Reply by MaHa on November 29, 2015 at 10:19am

Hi Iman,

I think after calculating the total transmittance of the IGU by "LBNL Window", you can write it manually in Honeybee-radiance glass material.

 

Permalink Reply by Iman Khayat on November 30, 2015 at 3:12am

Thanks masoome.