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Where to find/edit ground reflectance in OpenStudio

asked 2017-03-14 05:50:33 -0500

Kingo gravatar image

updated 2017-03-14 10:48:01 -0500

Hi!

Im currently working in OpenStudio and want to have lighting control using radiance. Everything works fine but i don't know where to find ground reflectans both visable and solar radiation. Does OpenStudio/E+ use some standard values that are hidden or does it just assume 0?

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answered 2017-03-14 10:47:45 -0500

The Radiance sky/ground models that are automatically generated for you in OpenStudio will ASSume 20% reflectance. The big caveat there is that the "ground" is modeled as an infinitely distant hemisphere that simply reflects 20% of the solar/sky radiation. In other words, the building is magically suspended in this environmental, radiating sphere. In real life[TM], the building is sitting on the ground, and the building casts solar shadows on that ground, thus dynamically altering the ground plane reflectance. So if you want to properly model the ground reflectance in Radiance you need to add some exterior shading polygons representing the local ground plane. In this case, the reflectance is simply the reflectance of the material you apply to it.

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Asked: 2017-03-14 05:50:33 -0500

Seen: 104 times

Last updated: Mar 14