Building zoning and classified control strategies for enhanced performance of solar-air source heat pump hybrid heating systems

The solar–air source heat pump hybrid heating system offers substantial potential for building energy conservation and carbon mitigation; however, its practical operation is constrained by efficiency losses, limited precision in demand-oriented regulation, and inadequate adaptability across diverse scenarios. To address these challenges, this study proposes an integrated control framework that combines a Building Zoning Model (BZM) with Classified Control Strategies (CCS). The BZM employs a two-level indicator system to systematically characterize building functional heterogeneity, thermal demand attributes, and operational constraints, and, through fuzzy decision rules, classifies heating conditions into three representative scenarios: Unified, Planned and Random Zone. On this basis, the CCS comprises three differentiated control modes: Type I for scenarios with smooth dynamics and weak constraints, Type II for multi-zone coupling under moderate constraints, and Type III for environments characterized by strong disturbances, tight constraints, and high randomness. A simulation model is developed and validated on a physical experimental platform, and the adaptability of the three control strategies under different zoning scenarios is evaluated in terms of indoor temperature, pump flow rate, tank temperature, and system energy consumption. In addition, CCS is compared with non-zoned control using five key performance indicators, including indoor temperature tracking error (RMSE), comfort violation rate (CVR), response time (RT), Pump flow variability (PFV), and energy use intensity per unit area (EUI). The results demonstrate that, relative to non-zoned control, RMSE is reduced by 29.8% and EUI is reduced by 12.8%, thereby significantly enhancing the overall performance of the hybrid heating system.