Passive climate control innovations in Hunan courtyard dwellings: Enhancing indoor environmental and energy efficiency through integrated systems

• The highlights of the study on integrating the Passive Climate Control system within Hunan, China’s courtyard buildings are summarized as follows: • Earth Air Tunnels and roof vents improve passive heating and cooling. • Glass roofing enhances daylight while preserving thermal comfort. • Passive airflow design reduces indoor PM2.5 from cooking. • Holistic system integrates heat, light, and ventilation control. • Retrofitting improves comfort while preserving cultural value. This study proposes an innovative passive climate control strategy for courtyard dwellings in Hunan, China, a region characterized by hot summers and cold winters. By integrating the Earth Air Tunnel (EAT) system and Daylighting and Ventilation (DV) system, this research enhances both energy efficiency and indoor environmental quality. The EAT system utilizes evaporative cooling and existing rain drainage infrastructure to improve natural ventilation, additionally Trombe walls and rooftop greenhouses optimize solar gain for passive heating. The greenhouse structure also significantly improves daylighting performance, reducing reliance on artificial lighting. Implementation of these technologies in courtyard dwellings result in an annual energy reduction of 3,888.2 kW · h (27.9 %), while enhancing indoor thermal comfort, lighting quality, and air circulation. These findings highlight the potential of integrating passive climate control systems into traditional residential buildings, offering a sustainable and energy-efficient model for regions with similar climatic conditions.