Hello

It is possible to calculate the solar irradiation entering to the space through a window?

I have seen that DIVA can calculate annual irradiation at node locations (vía Radiation Maps-Grid Based). I have used a grid in the interior of a room with one fully glazed facade . But I have some queries:

1) What solar irradiance spectrum is measured after passing through glass?

2) I have used the following glass material:

# Glazing_DoublePane_Clear781: Tau_vis = 0.781; SHGC= 0.703 ; U-Value= 2.785W/m2K
# visual transmittance: 78.1%
# visual transmissivity: 85.1%
void glass Glazing_DoublePane_Clear_78.1
0
0
3 0.851 0.851 0.851

Those parameters defines the way "visible light" is transmitted through the glass. But, if I want to know the transmitted solar irradiation, do I need to specify the solar transmittance of the glass instead of the visible transmittance? 

Thanks in advance

Abigail

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How did you get those results?!

I can see the window in my 3D model !!! Besides, I ran the model again with another name and my results were equal than those obtained before.

By the other side, is it necessary to change the visible reflectance of the materials to the solar reflectance? How can I convert the values or the visible reflectance to the solar reflectance?

Thanks again for your help!!!

Attachments:

Yes, I saw that the window layer was turned on in your Rhino model.  Possible reasons it wouldn't have been exported include:

1) The layer was locked when you started the run.

2) There was no material assigned to that layer when you started the run.

3) Either (1) or (2) obtained in a previous run, and you selected "Yes" to the "Reuse *.DC files" prompt, causing the issue to recur:

Not sure what you mean regarding reflectances.  Reflectance is not one of the glass material parameters in Radiance (instead it is an implicit consequence of the transmissivity parameters).  In any case, there is no "conversion" between visible and solar properties -- they must be based on physical measurements of the material.  As I mentioned previously, unless you have a special, spectrally selective glass, visible and solar transmissivity are likely to be very similar.

Jon

Jon

I have seen that Diva did not recognize a new material. I do not why. After some trials, I changed the description and name of this new material from:

# Glazing_DoublePane_Clear781: Tau_vis = 0.781; SHGC= 0.703 ; U-Value= 2.785W/m2K 
# visual transmittance: 78.1%
# visual transmissivity: 85.1%
void glass Glazing_DoublePane_Clear_78.1
0
0
3 0.6584 0.6584 0.6584

to

# Glazing_DoublePane_ClearAir: Tau_vis = 0.781; SHGC= 0.703 ; U-Value= 2.785/m2K 
# visual transmittance: 78.1%
# visual transmissivity: 85.1%
void glass Glazing_DoublePane_Clear_65
0
0
3 0.6584 0.6584 0.6584

Then I checked the *.rad file and the window was present. Do you know why the first material was wrong? 

(I have used the solar transmissivity instead of the visual transmissivity). What material did you use in your simulation (image that you attached before)?

-----

About my other last question, it was about the opaque materials such as walls, ceiling and floor. For example, the Generic Ceiling 80 has a visible reflectance of 80. But, What is its solar reflectance? Should I specify the solar reflectance instead of the visible reflectance? Besides, do you know where I can find this information?

Once again, many thanks

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