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how to create a model of semi-transparent PV window in radiance

asked 2019-07-10 07:30:38 -0500

Jing Gao gravatar image

I want to create a model of semi-transparent pv window in radiance and use 3-phase to simulate. But the 3-phase method needs the xml format file. If the gap between the pv batteries is not uniform, how to create a window model and get the xml format file? Should i use the sketchup and how to do ?

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answered 2019-07-10 13:04:00 -0500

So you merely want the daylighting? You're not interested in calculating the PV production? Typically PV windows do not change their visible transmittance and spatial distribution, so why do you even need three phase, unless you want to model the effect of an interior blind or shade? As for the net transmittance, allowing for non-uniform spacing of the "pv batteries", you could just model the pv as opaque objects directly in front of the glass polygon, I'd guess. With an accurate model of the glass, you could just do "single phase" (what I call it) or "two phase" (what everyone else calls it), where you calculate one matrix: the contribution of the sky patches directly from the sky to the interior point(s).

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Thank you for your answer. At present, I only consider the lighting performance of semi-transparent pv window. But the transmittance and reflectance of transparent glass and PV modules vary with wavelength, so how should i creat the model of simulation?

Jing Gao gravatar imageJing Gao ( 2019-07-11 02:22:17 -0500 )edit

OK so have a look at "mixfunc", which allows you to make a single Radiance polygon have two material characteristics. Define a "glass" type for the glass, and probably a "plastic" material for the pv modules, and then use a mixfunc to apply those two materials in a pattern that mimics the arrangement of the modules. I would get transmittance and reflectance from the manufacturer(s) of the panels, and plug them into the aforementioned Radiance primitive types (glass and plastic).

rpg777 gravatar imagerpg777 ( 2019-07-11 11:40:34 -0500 )edit

Thank you very much for your answer.

Jing Gao gravatar imageJing Gao ( 2019-07-12 02:05:29 -0500 )edit

Sorry to bother you again.After I use a mixfunc, how do I use two xml files for PV and transparent glass in 3-Phase?

Jing Gao gravatar imageJing Gao ( 2019-07-14 02:50:57 -0500 )edit

Again, if you are merely modeling a PV glass, with no shades, then you don't need to do three phase at all. Make a mixfunc and apply it directly to the window polygon. No need for BSDFs.

rpg777 gravatar imagerpg777 ( 2019-07-14 22:44:45 -0500 )edit

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Asked: 2019-07-10 07:30:38 -0500

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Last updated: Jul 10