Computational and the real energy performance of a single-family residential building in Poland – an attempt to compare: a case study

Department of Air Conditioning, Heating, Gas Engineering and Air Protection, Faculty of Environmental Engineering, Wrocław University of Science and Technology, 4/6 C.K. Norwida st. 50-373 Wrocław, Poland

^* Corresponding author: piotr.kowalski@pwr.edu.pl

Abstract

The paper presents energy use for heating and ventilation (one of the energy performance components) determined in three ways. A case of a single family building located near Wroclaw in Poland is analyzed. The first and the second variant are both computational and the third presents actual measured energy consumption. Computational variants are based on the Polish methodology for the EPC (the Energy Performance Certificate). This methodology is based on ‘the Energy Performance of Buildings Directive 2010/31/EU’. Energy use for heating and ventilation is calculated using monthly method presented in EN ISO 13790. In the first computational option standard input data (parameters such as indoor and outdoor air temperature etc. are taken from standards and regulations) are implemented. In the second variant this input data are partially taken from measurements. The results of energy use from both computational variants are compared to the actual measured energy consumption. On the basis of this comparison the influence of three factors: solar radiation heat gains, building air tightness and the SCOP of the heat pump on energy use calculations are analyzed. Conclusions aim to point the differences between them and the actual energy consumption.