# some questions about using five-phase method for a space with clear glazing

Hello,everyone I find this picture from Tutorial-Five-phase method.pdf . I want to ask some questions about daylighting simulation of clear glazing in five-phase method.
1.

If i want to export the BSDF file of the clear glazing from WINDOW7.5 ,what should i set for WINDOW7.5 ?
2.
For Sun-Coefficient simulation, what should i do for proxy surfaces of clear glazing with BSDF file output from WINDOW7.5?
3.
Why simulate with eastBlinds.vf ? If there is only a clear glazing , in addition to using this view file:south.vf for simulation, do i need to simulate other view files ?

Assuming that this question is related to the other one that you posted, in my opinion you don’t really need to go the 5-Phase route. The Three- and Five-Phase method make sense if you have complex fenestrations (like blinds, perforated shades etc) and if there multiple types of those to evaluate parametrically. Since you are dealing with a standard glazing, it would be a lot simpler to just use the standard Daylight Coefficient Method or the 4 Component Method.

1. Creating BSDFs for clear glazing: Since you already have your glazing data in Optics-compatible format, you can create a BSDF for it by using genBSDF. You can export a RAD definition from Optics, then use that material with a simple glazing polygon and follow the genBSDF tutorial to export a XML-format BSDF. For the final step of the 5-Phase method, instead of the Tensor-tree BSDF with proxy-geometry, you can use the standard glazing polygon directly (There might be a better alternative to this, I am just pointing out the way I know how to).
2. “Why simulate with eastBlinds.vf ?” from the tutorial: I was just trying to demonstrate the matrix-reuse feature within the multi-phase methods i.e. one only needs to recalculate the View Matrix and all the other matrices can be reused from the previous simulation for the south view. So, you don’t have to simulate multiple views if they aren’t required.

Regards,
Sarith

For direct sun coefficients simulation in 5-phase method , i see the following file for blinds.

How to creat the same file for clear glazing without blinds , if i have the xml file for clear glazing .

Since you have a clear glazing, it would be better to use the glass material directly instead of using the XML file with the BSDF material.

So it would be something like:

``````void glass Glazing
0 0 3
0.5 0.5 0.5
Glazing polygon glazingGeo 0 0 12.. etc
``````

If you do intend to use the XML file instead, then the definition would be something like:

``````void BSDF Glazing
6 0 pathToXMLfile 0 0 1 .
0 0
Glazing polygon glazingGeo 0 0 12.. etc
``````

Regards,
Sarith

Thank you very much .

I want to ask another question . I saw this picture in the file .

Is the method for exporting Transmission matrix from WINDOW7.5 software in the five-phase method the same as the method for exporting Transmission matrix from WINDOW7.5 software in the three-phase method?

For the two instances that you have highlighted with black rectangles, yes, the method will be the same. If you are asking this with regards to your simulation with clear glazing, then the T matrix will be generated with genBSDF (as also pointed out in the figure).

Thanks a lot.
Because I only have optical properties file of a certain laminated, I created a complete three-layer glazing in the WINDOW software, and then exported the BSDF file in XML format from the WINDOW. I found using 3PH and 5PH method simulation, for the measurement points near the window, the illuminance value obtained by the three-phase method is 22186.67lux, but the result obtained by the five-phase method reaches 1465451lux. Illumination values obtained by the two methods are too different.What do I need to check to make sure my simulation is accurate?

The results from the Three-Phase simulation, especially in instances with direct-sun, are expected to be less accurate than the Five-Phase method. One way to compare the accuracy would be to compare the results with a standard rtrace simulation for the same daylighting conditions.

An inter-model comparison between these simulation types (and more) is discussed in:
Brembilla, E., & Mardaljevic, J. (2019). Climate-Based Daylight Modelling for compliance verification: Benchmarking multiple state-of-the-art methods. Building and Environment , 158 , 151-164

Regards,
Sarith

Thank you very much.