BeREAL – development, test and implementation of Be10

The objective of this research project is to develop an online software application – BeREAL. The application is an add-on (and a supplement) to the SBi application, Be15, which is used to calculate the predicted energy consumption of buildings. BeREAL focuses on the “performance gap” – the often quite large difference between the calculated predicted energy consumption of buildings and the measured (real) energy consumption. BeREAL can handle uncertainties in the calculation of the predicted energy consumption of the building. The application allows minimum and maximum values for all important input parameters. The BeREAL output is also given as a confidence interval. To achieve this, BeREAL has automated many calculations (often more than 1000) that otherwise was needed to be done manually. The recommendation to include uncertainties in the calculation is in full alignment with the recommendations of the new industry guide made by Innobyg. The BeREAL application also calculates og identifies 10 input parameters that have the greatest impact on the predicted energy consumption of the building. In addition to this, BeREAL uses a weather database from Aarhus University, which via GPS coordinates can deliver hourly-based data 45 years back in time for the exact location of the building. Thus, BeREAL uses “the real weather” as opposed to Be18, which is based on DRY (Design Reference Year). It is very important to include precise weather data in the energy consumption 5 calculation, as variations in the weather typically explains up to 20 % of the variation in energy consumption of a given building. The application can be used in two ways: In the design stage it can be applied to develop more realistic forecasts (predictions) of the energy consumption of a given building. In addition to this, the application is able to identify factors that are most critical for the energy consumption. When a building is put into operation, BeREAL can be used to evaluate whether the measured energy consumption is acceptable – and to explain the causes of energy consumption levels that are to high.