Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question

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


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?

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

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.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer


Question Tools

1 follower


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

Seen: 186 times

Last updated: Mar 14 '17