Sustainable renovation solutions for Finnish apartment buildings

To achieve carbon neutrality in Finland, it is necessary to improve energy efficiency of residential stock through renovation. The study evaluates the performance of several renovation technologies in a Finnish apartment building by simulation. The renovation technologies include roof and balcony walls’ thermal insulation, vapour barrier, heat distribution pipes’ thermal insulation, daylighting louvers, mechanical balanced ventilation systems with heat recovery, bi-facial photovoltaic panels and ground-source heat pump. IDA ICE was utilized to simulate the demo building model, serving as the reference for renovation
technologies’ simulations. The renovation technologies were divided into the passive, ventilation and generation packages, and then integrated into the reference model to examine their effect on primary energy, CO2 emissions and indoor climate. The biggest impact on CO2 emissions (31% reduction) was gained by installing ground-source heat pump, which converts significant coal-based district heating into low emission electricity. Converting the mechanical
exhaust ventilation into mechanical balanced ventilation with heat recovery was another significant measure, reducing CO2 emissions by 21%. In contrast, the thermal insulation technologies possess lower emission reduction potential. However, the thermal insulation technologies and mechanical balanced ventilation systems slightly worsen overheating problem in summertime. Installing daylighting louvers significantly reduces summer indoor temperature.