Optimization of Air Source Heat Pump Systems over the Heating Season through the Use of Renewable Energy Sources
air source heat pump, multi objective optimization, thermal storage
The coming into force of the mandatory European Directive 2009/28/CE requires to increase the role of renewable energy sources to satisfy the energy consumptions of new buildings and major renovations. In this respect, the vapor-compression heat pumps coupled with PV panels are a promising technology and, consequently, they are increasingly used for residential heating applications. This HVAC solution is especially advantageous in high performance building when low temperature hydronic systems (e.g. radiant panels) are adopted. Nonetheless, the seasonal performance of the heating system is strongly dependent on HVAC design, such as the system sizes (heat pump, water storage tank, PV battery), and on the system control strategies adopted. Besides, the pursuit of high efficiency heating systems can undermine the comfort conditions inside the building. Thus, an optimal design and control of the heating systems installed in high performance building is essential to ensure the reduction of energy consumption and the achievement of thermal comfort for the entire heating season. This study presents the optimization of different system configurations and control strategies for several high performance houses. In particular, massive and lightweight structure with low or high solar gains building are considered with the purpose of studying the optimal system design in different building configurations. The dynamic simulation of the house and its heating system was firstly set up by the TRNSYS simulation suite. Following on from this point, the optimization of the energy systems was performed by coupling the simulation code with a Genetic Algorithm, with the purpose of minimizing the energy consumption and thermal discomfort time. In conclusion, this study demonstrated an application of dynamic building simulation as a tool to optimize different control strategies and system configurations in order to overcome the issues of coupling heat pump systems in high performance buildings. Results highlight the role of thermal storage in enhancing the energy performance by allowing the air source heat pump to operate in optimal conditions. Besides, the study points out the issues of coupling systems with high response time in high performance buildings.