Performance and cost analysis of a heat pump cascade installation in an existing apartment building

Abstract

The Master's Thesis focuses on the potential strategies to curb greenhouse gas emissions associated with residential space heating and domestic hot water in urban settings dominated by individual gas boiler systems. The study introduces an innovative heat pump cascade deployed in an Austrian multi-apartment building featuring a series of interconnected heat pumps. A serial heat pump setup, including a communal roof-mounted heat pump supplying moderately heated water circulated through the building's staircases and individual mini heat pumps within each apartment, further elevating water temperature for space heating and domestic hot water. The study evaluates this serial heat pump setup's performance and the Levelized Cost Of Heat.The investigation addresses various aspects:Subject: This study centers on evaluating the efficacy of a unique heat pump cascade design for emission reduction in multi-apartment buildings.Main Issue and Objective: The main focus is to assess the viability and effectiveness of a serial heat pump setup in minimizing greenhouse gas emissions associated with residential heating.Central Research Question: The central research question addresses the performance and sustainability of the proposed heat pump cascade configuration.Methods Used: The investigation employs a comprehensive approach encompassing a case study description, meticulous analysis of mini and roof heat pumps, exploration of their interactions, and a thorough evaluation of the overall system's efficiency.Findings: Data-driven insights reveal that the cascade configuration, consisting of a roof and mini heat pumps, achieves a commendable annual Coefficient of Performance (COP) of 1.52. This COP includes distribution losses, storage losses, Stand By consumption of Heat pumps and partial load operation. These factors are not accounted for in Heat Pump COPs measured on a test bench. Considering 54% distribution losses occurring in multi apartment houses with a central gas boiler the COP would be around 3.30.The Levelized Cost of Heat (LCOH) is estimated at 0.97 EUR/kWh or 34.61 EUR/m2 per annum. In order for a central gas heating system to match the LCOH achieved by the Heat Pump Cascade, it would need to have a 40% lower installation cost.The analysis emphasizes the influence of user behavior, installation factors, and climatic conditions on performance.Conclusion and Future Prospects: The study underscores the potential of the serial heat pump setup to reduce emissions effectively. It highlights the need for user education, system optimization, and the potential integration of artificial intelligence for enhanced efficiency. Moreover, the research indicates that further investigation over a complete annual cycle is crucial for robust results.In conclusion, this research sheds light on a pioneering serial heat pump configuration's potential to mitigate emissions in urban multi-apartment buildings. It provides insights into its Coefficient of Performance (COP) and Levelized Cost of Heat (LCOH).