As a HVAC company, a part of our business is to calculate heating and cooling loads.
One of the heating & cooling load analysis inputs is "ground level", which defines underground surfaces. Ground is selected from planar elevation levels. Obviously, most of the buildings has no planar ground surfaces. As a result, some open-to-air surfaces including windows, doors and exterior walls are counted as underground surfaces. This effects the load calculations; loads are lowered about 5 times, which makes the calculation useless.
If there is an available solution, I would kindly ask any experienced guy to share with me.
All right, I found some information about my case.
1- MEP 2012 does not have Mass & Site option so we can't create toposurfaces.
2- Since we can't build toposurfaces, we can not cut the walls from the mid, defining below grade and above grade parts.
Now the question is; even if we use Revit MEP 2012, can we find any means to define multi-level grounds, so that underground and above ground elements can be truely distinguished in load analysis? Most of the basements have one side below grade, one side above grade with windows on it, and we fail to make load analysis over such projects.