I'm wondering if anyone has a good workflow for incorporating steep nearby hills and trees in the model. I'm thinking to include approximate shading surfaces to simulate the fact that some surfaces won't receive much direct solar radiation at certain orientations, but curious if there is a more accurate way of coming up with such shading surfaces.
@edwinguerra first of all its important to identify the purpose of your model - is it for code compliance or realistic energy estimation? If for code compliance, you may have to include the impact of terrain but exclude the impact of trees. I have built surrounding terrain previously using contour maps from surveys and component blocks in DesignBuilder, am unsure of equivalent in IES or other. You can build approximately using few contours as a guide or you can build in more detail using all available contours. Be sure to set a solar absorptance value for the terrain component blocks(or shade surfaces), a figure commonly used for ground is 0.8. Trees can also be built using transparent component blocks, you may choose transmittance from 0.5 to 0.2 (suggested) depending on the type of tree. A helpful paper for modelling trees can be found here. Hope that helps.
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@edwinguerra are you asking about how to do this for a specific simulation tool? If so, please add a tag for the tool to your question so that others can provide better help.
yes, I think it is a general modeling question. I use IES-VE and OpenStudio, but in general, wondering how people would approach this. It feels very approximate to draw shading surfaces around your building. My assumption is that you can't bring in a complex terrain as a shading surface, but maybe someone has done it or has tips.
@edwinguerra you may also consider adjusting the Terrain field in the Building object (EnergyPlus).