Load aggregation mitigates air-conditioning efficiency degradation in high-performance housing under climate warming

Source abstract

High-performance housing is expected to become an increasingly important residential form in the transition toward carbon neutrality and climate adaptation. However, when conventional decentralized split-type air-conditioning systems are used in such houses, an efficiency penalty may emerge. As high-performance envelopes reduce room-level thermal loads, individual units are required to operate for prolonged periods at ultra-low part-load ratios, resulting in lower coefficient of performance (COP) and weakened dehumidification during humid summer conditions. Under these conditions, a load aggregation strategy is investigated, whereby the whole-house thermal load is managed by a single strategically located split-type heat pump, assisted by a double-height void and wall-mounted cross-room ventilation fans for air distribution. By consolidating fragmented room-level loads into a building-scale load, operation in a more continuous and efficient regime is enabled. Results across different climate zones indicate that, in high-performance housing, this configuration can reduce air-conditioning energy consumption by nearly 50% while maintaining stable indoor thermal comfort and substantially reducing excessive indoor humidity under the assumed ventilation, moisture generation, and control conditions. These findings suggest that load aggregation can overcome the air-conditioning efficiency penalty in high-performance housing and provide a practical system design strategy for future climate conditions.