Calculating stack effect in atrium

#1

Hi all,

I am trying to do a simulation of the stack effect in an atrium of an office building in Butterfly. The building consists of 5 floors with an open office plan and a top floor with technical installations. Fresh air is supplied trough the ceiling in the office floors, then flows to the atrium and is extracted in the atrium on the top floor. The roof of the ceiling is fully glazed.

Because of the skylight there will be a stratification of the air. The stack effect will be increased because of the ventilation set-up. Now, I am trying to calculate the temperatures in the atrium with Butterfly.

I am familiar with energy and daylight calculations with EnergyPlus, Honeybee, Radiance and Ladybug, but the world of CFD is new to me. If I understand it correctly, it is possible in Butterfly to add interior surface temperatures and mean air temperature as boundary conditions for the CFD analysis. Now, I am wondering if the impact of solar radiation (which is huge in this case) is fully taken into account if I do a CFD analysis by just adding surface temperatures and mean air temperature (which I will calculate with Honeybee). Or am I missing an important aspect to calculate the influence of solar radiation in Butterfly?

Kind regards,
Siemen

#2

Hi, sg, may i ask what do you mean by mean air temperature?
I saw there was only wall, inlet and outlet boundary condition in the example file “atrium study” .
Is the mean air temperature necessary and where can we input them?
Thx~