According to the Institute for Energy of the European Commission Joint Research Centre, HVAC (Heating, Ventilation and Air Conditioning) accounted for 11% of the EU electricity consumption in 2007. Annual energy simulations of buildings are increasingly being used for optimization of energy consumption.
These simulations primarily rely on one-dimensional methods. Computational Fluid Dynamics on the other hand are generally utilized in building applications among others for predicting thermal comfort and developing HVAC components. Currently annual CFD simulation of one room or even an entire building is practically impossible due to limited computational power.
At the Hermann Rietschel Institute, department of Building Energy Systems at the Technische Universität Berlin, a new method for annual energy simulation is being developed, which makes it possible to run 3D annual energy simulations using existing CFD models within acceptable calculation times. With this method, it is also possible to run flow simulations for the critical zones within a building, where the annual energy simulation delivers realistic boundary conditions.
A case study for an office building using this 3D method is carried out and the results are compared with a 1D simulation. During this study, the parallel performance of the 3D simulation is also tested. This case study showed that, it is possible to run 3D annual building energy simulations with this method in practice.