Hi all, I am studying the effect of altering the window glazing on energy consumption of a medium office building. The modeled test cell is described as a single thermal zone with a single window on one of the walls. As it is considered as a small part of the whole office building, only the wall with the window is assumed to be an exterior surface (boundary condition:Outdoors) and others walls plus roof and ceiling are considered adiabatic in Building Surfaces: Detailed in Energy +. In such a case, the heating load would be zero almost all year. When I change all surfaces to the boundary condition of "Outdoors" instead, the results look fine, though. It seems that I am doing something wrong with the adiabatic thing is E+, because there exist a paper with the same method in EnergyPlus (Titled: Comparative energy and economic performance analysis of an electrochromic window and automated external Venetian blind) with fine results. I am using Ideal Loads air system as my HVAC, in case it matters. Hope it is clear, as I am new to this group and not able to attach pictures. I would really appreciate your comment.