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How to use two .xml files by 3-phase method for dynamic simulation

asked 2019-07-14 21:37:20 -0500

Jing Gao gravatar image

Hello,When using the 3-phase method for dynamic simulation, I encountered the following problems. Firstly,If a window on a wall has two different xml files on the top and bottom of the glass, like semi-transparent pv window, how to use these two xml files in the 3-phase method ? Secondly, in 3-phase method how to set the parameters of glow about glazing_glow, sky_glow and ground_glow ? What effect does the set value have? Is there a regular value? Thank you.

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answered 2019-07-15 09:32:41 -0500

If you have two different BSDFs (xml files) for two different panes of glass, as you have described here (i.e. an upper daylight window and a lower view window), then you would simply model the two different windows explicitly and assign the BSDFs accordingly. Each window would be a separate simulation.

The glows for the window, sky and "ground" are all 1 in a daylight coefficient simulation. If you model the sky/ground envelope as a sphere, Radiance will automatically apply a ground reflectance factor to the radiance if the ray intersects below the horizon (default is 0.20).

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By the way, you should also model a local ground plane in order to capture the shading effect of the building you're modeling and its local environment (which you should also model)). The onus is on you to ensure that the reflectance of local exterior geometry matches the ground reflectance you're assuming for the distant "environment sphere" too. This is all well-documented in Rendering with Radiance (going back twenty years now).

rpg777 gravatar imagerpg777 ( 2019-07-15 10:39:17 -0500 )edit

Thank you very much. When modeling a window separately, is it to remove the hole in the other window and restore it to the wall ? If there are many windows with the same xml file on one wall, what should I do if the manual input of coordinate points is complicated when modeling the wall holes?

Jing Gao gravatar imageJing Gao ( 2019-07-15 21:59:43 -0500 )edit

I don't understand. When I say model two windows, I mean generally you'd model one opening, and then place two window polygons representing the two different areas of glass, and there'd be a mullion between the two. If there are many windows, you could model them as a continuous ribbon, this is often done in energy models where people don't seem to care about the quality of the simulation (sorry, I can't help myself). For a proper daylight model though, generally the interior architecture and the fenestration are modeled as accurately as possible, or reasonable.

rpg777 gravatar imagerpg777 ( 2019-07-16 10:55:35 -0500 )edit

If you are trying to model this without the help of a proper 3D modeling tool, then I'd say go get yourself a proper 3D modeling tool. ;)

rpg777 gravatar imagerpg777 ( 2019-07-16 10:56:53 -0500 )edit
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Thank you for your response, it helped a lot.

Jing Gao gravatar imageJing Gao ( 2019-07-16 21:31:00 -0500 )edit

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Asked: 2019-07-14 21:37:20 -0500

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Last updated: Jul 15 '19