Energy, economic and environmental(3E) assessment of low- GWP combined ASHP systems for residential building heating decarbonization
This study conducted a comprehensive energy, economic, and environmental (3E) evaluation that considers energy performance, economic feasibility, and environmental impact in residential heating and domestic hotwater systems. The assessment incorporated ASHP and ASHP-VI cycles as well as low-global-warmingpotential refrigerants, with the overarching goal of supporting decarbonization in the residential sector. Previous studies have often been limited by narrow climate conditions, restricted refrigerant options, simplified system configurations, or evaluations based on a single performance metric. To overcome these constraints, the present study developed a simulation-based framework that integrates multiple climates and system arrangements, thereby providing a broader and more holistic perspective on 3E performance. In addition, a hybrid combined ASHP strategy was introduced to address the operational instability and performance degradation commonly observed in ASHP systems during winter operation. In this configuration, the supplywater temperature is controlled based on the compressor discharge temperature, and an auxiliary boiler is incorporated to supplement the heating demand when necessary. The results indicate that the application of ASHPs reduced energy consumption by an average of 57.7% across all regions compared with the conventional gas-boiler system. The ASHP-VI system using R290 achieved the highest overall performance, with an average reduction in energy consumption of 72.4%. This configuration also demonstrated the most favorable economic and environmental outcomes, achieving carbon-emission reductions of up to 36.2% compared with the gas boiler. These findings provide meaningful insights that can support the wider adoption of safe, efficient, and environmentally responsible heating technologies in the residential sector, particularly as national policies increasingly emphasize the transition toward carbon neutrality.