Optimization of heating system for residential building according to life cycle costs when multiple heat sources are utilized with heat pump

摘要

The basis of this thesis was to optimize heat pump that uses multiple heat sources to get competitive heating system for residential building when life cycle costs are considered. The objectives were to compile necessary information to calculate life cycle costs for heating system of residential building and start to compose of designing program for heat pump based heating systems. Examinations were made for the purchase energy need of residential building. Features of heat pump, considered refrigerant and potential heat sources were examined to find out heat production potential of heat pumps. Necessary information for life cycle cost calculation was also examined. Collected data was used in two case analyses to design selected heat production systems and calculate their life cycle costs.On the basis of case analyses heat pump based hybrid heat production systems are very competitive on life cycle cost comparison against district heating when residential building uses a lot of energy. New buildings use considerably less energy and achieved energy cost savings with heat pump systems may not be enough to cover the relatively high investment cost in reasonable time period compared to district heating system.The calculation method was found to require further development to at least include the cooling energy need of the building. Cooling demand will continue to grow in the future, which improves the heat pump based heat production systems competitiveness compared to other systems.