I am studying the sensitivity analysis of heat transfer coefficients of different orientations of walls and windows to energy consumption. I consider the impact of ground radiation on walls and windows with different orientations.

I guess I need to express the ground around the building. I don’t know how Include the ground around the building in the energy modeling. Link the geometry of the ground to the shade of the HB MODEL？

Thank you very much for your help.

What I did is that I just create a surface at the bottom of the building and define the roughness and detailed properties in the HB surface, so it will reflects the sunlight onto the building. But I’m not sure it’s the right way to do it or not. Hope there will be better option to solve it and also I was think what numbers should be given to the ground, is there any suggestions for the properties should be used?

1 Like

That’s the most accurate way to do it, @David1 . When you don’t represent the ground with an explicit geometry, Radiance includes an emissive “ground hemisphere” that mimics a 0.2 reflectance ground material. But nothing is quite as accurate as actually modeling the reflection off the ground with an explicit geometry.