The Impact of Parallel Energy Consumption on the District Heating Networks

The aim of this study is to evaluate and compare the impacts of heat recovery ventilation (HRV) and exhaust air heat pump (EAHP)-based solutions used in renovated buildings, which make it possible to reach performance class C in district heating (DH) area CO₂ emissions, primary energy consumption and total energy costs for consumers. Evaluation is based on the methodology presented in the previous research paper [1]. Calculation results show that the use of EAHP has a negative impact on DH sustainability (heat losses in the DH network, DH heat price, reduced consumption of DH heat) and CO₂ emissions related to energy delivery (heat and electricity) to consumers in the DH area. Positive aspects of the EAHP use include the fact that almost the same primary energy consumption level can be achieved with lesser (up to 7 %) annual costs (annual capital costs, DH heat costs and electricity costs) and lower initial investments (about 10 %). At the same time, every renovated building with EAHP will experience a negative impact on heat prices. In DH areas where almost all buildings are renovated with EAHP, cost savings are not as evident compared to buildings with HRV in DH areas where the use of parallel consumption solutions (EAHP) is minimized. It is reasonable to promote these renovation packages and solutions that benefit the building’s primary energy reduction, and also do not increase electric energy consumption (additional electric power generators are needed) and do not damage DH networks.