Vahur - thanks for the link, I think I understand it. Very helpful.
Laszlo - that's correct, there is heat loss into the ground at this junction but unfortunately there appears to be no way to calculate it as I can't proceed without describing external air area.
laszlonagy wrote:This is not workaround. This is the only proper way. The "Soil" environment is not a working tool at all. It is not working as it should do. Currently it works as a simple material, but is not analyzed during the calculation.
I asked the guys at GRAPHISOFT about this.
I was told that you could simply specify the soil fill as "External Air" and specify the temperature of the soil for it. The results should still be correct this way.
Then, in the next Dialog, you would not define a "Soil".
This is a workaround but it will achieve what you are trying to do.