Measured performance of exhaust air heat pumps in Finnish apartment buildings

¹ The Finnish Real Estate Federation, Annankatu 24, FI-00100, Helsinki, Finland
² Tallinn University of Technology, Department of Civil Engineering and Architecture, Ehitajate tee 5, Tallinn, 19086, Estonia
³ Aalto University, Department of Civil Engineering, Rakentajanaukio 4, FI-02150, Espoo, Finland

^* Corresponding author: petri.pylsy@kiinteistoliitto.fi, petri.pylsy@aalto.fi

Abstract

The energy efficiency of existing apartment buildings is playing an important role in energy and climate targets. In Finland, mechanical exhaust ventilation system is commonly used in older apartment buildings. Hence, there could be an energy saving potential by an exhaust air heat pump system (EAHP). In this work two cases have been studied. Buildings were built in 1960’s and 1970’s and in renovation equipped with hybrid heating system: district heating and exhaust air heat pump system. Two years measurement data, 2018 and 2019, was collected to evaluate the performance of exhaust air heat pump systems. According to measurement data the monthly coefficient of performance (COP) was calculated as well as seasonal coefficient of performance (SCOP) was defined. The monthly COP values varied from 3,1 to 4,6 and SCOP values were about 3,7. Heating energy cost savings were 23-31 %. Energy performance class before and after EAHP installation was calculated. If at least 50 % of heating energy consumption was covered by EAHP then also energy performance class was improved.