Optimization of emission reducing energy retrofits in Finnish apartment buildings

• Published in: E3S Web of Conferences Vol. 111; p. 3002
• Main Authors: Hirvonen, Janne, Jokisalo, Juha, Heljo, Juhani, Kosonen, Risto
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 01.01.2019
• Subjects: Apartment buildings; Buildings; Carbon dioxide; Carbon dioxide emissions; Cost control; District heating; Emission analysis; Emissions control; Energy conservation; Exhaust systems; Heat exchangers; Heat pumps; Heat recovery; Heating; Heating systems; Housing; Insulation; Life cycle costs; Life cycles; Multiple objective analysis; Optimization; Residential areas; Retrofitting; Sewage; Ventilation
• ISSN: 2267-1242; 2555-0403; 2267-1242
• DOI: 10.1051/e3sconf/201911103002

This study examined the cost-optimality of energy renovation on Finnish apartment buildings of different ages, built according to different energy performance requirements. Multi-objective optimization was utilized to minimize both CO 2 emissions and life cycle cost (LCC). IDA-ICE simulations were performed to obtain the hourly heating demand of the buildings. Four building age classes and three heating systems (district heating, exhaust air heat pump and ground-source heat pump) were separately optimized. With district heating, it was possible to reduce emissions by 11%, while also reducing LCC. With heat pumps cost-savings could be achieved while reducing emissions by over 49%. With maximal (not cost-effective) investments, emissions could be reduced by more than 70% in all examined cases. In all cases, the cheapest solutions included solar electricity and sewage heat recovery. In old buildings, window upgrades and additional roof insulation were cost-effective. In new buildings, demand-based ventilation was included in all optimal solutions.