This study introduces a control-oriented renewable ventilation architecture in which phase change material (PCM) is integrated with a hybrid earth–air heat exchanger (EAHE) and photovoltaic–thermal (PVT) system. Unlike conventional PCM applications that focus primarily on thermal smoothing, the present work demonstrates that latent thermal storage can fundamentally modify the optimal supervisory control of ventilation systems under climatic uncertainty. A stochastic multi-year optimization framework based on six years of hourly weather data is developed to simultaneously optimize system geometry and hourly control of airflow rate and outdoor-air fraction. The objective is to minimize the annual net ventilation energy balance—defined as the combined sensible, latent, and fan energy offset by on-site PV generation—while constraining comfort risk using a CVaR-based metric. Results reveal that PCM integration shifts the ventilation system toward a thermally stabilized control regime, enabling substantial reductions in airflow and outdoor-air intake without compromising comfort robustness. The optimized configuration achieves a negative annual net ventilation energy balance within the ventilation system boundary and reduces extreme discomfort risk by more than 80% compared with a conventional baseline. These findings demonstrate that PCM can act not only as a thermal storage medium but as a structural enabler of low-energy, risk-aware ventilation control in hot–dry climates.
