International Scientific Journal

Thermal Science - Online First

online first only

CFD-simulation of indoor climate in low energy buildings computational setup

In this paper computational fluid dynamics (CFD) was used for simulation of the indoor climate in a part of a low energy building. The focus of the work was on investigating the computational setup, such as grid size and boundary conditions in order to solve the indoor climate problems in an accurate way. Future work is to model a complete building, with reasonable calculation time and accuracy. A limited number of grid elements and knowledge of boundary settings are therefore essential. An accurate grid edge size of around 0.1 m was enough to predict the climate according to a grid independency study. Different turbulence models were compared with only small differences in the indoor air velocities and temperatures. The models show that radiation between building surfaces has a large impact on the temperature field inside the building, with the largest differences at the floor level. Simplifying the simulations by modelling the radiator as a surface in the outer wall of the room is appropriate for the calculations. The overall indoor climate is finally compared between three different cases for the outdoor air temperature. The results show a good indoor climate for a low energy building all around the year.
PAPER REVISED: 2015-10-15
PAPER ACCEPTED: 2015-10-15
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