Comparison of energy simulation programs via a case study

Recently, the use of energy simulation programs has become widespread in order to be able to evaluate design alternatives in new buildings and to assess retrofitting alternatives in existing buildings. Having a user-friendly interface and a material library consisting of up-to-date building materials as well as modelling the building and its energy systems realistically become important for selecting the simulation program to be used. In this study, the building of Nuclear Science Institution of Ege University, located in Bornova, Izmir province, is modeled via BEP-TR, DesignBuilder and eQUEST energy simulation programs and the annual energy consumption of the building is determined. The results show that the lowest building total energy consumption was calculated by the DesignBuilder program whereas the building's total energy consumption obtained by the BEP-TR program was almost 345% higher than the value calculated by the DesignBuilder program. The highest energy consumption category was found to be the heating consumption by the BEP-TR program whereas it was found to be the cooling consumption by the DesignBuilder and eQuest programs. In order to determine the reasons for the differences in the results, the programs were compared and recommendations towards improving each of them are presented.