System configuration and control process of a combined convective cooling and radiant floor heating system

Radiant floor heating and convective cooling systems are widely adopted in residential buildings in Korea due to their respective advantages in thermal comfort and cooling performance. However, these systems are typically operated independently. This study proposes a novel simultaneous heating and cooling system that combines convective cooling with radiant heating to improve energy efficiency while maintaining high thermal comfort in residential buildings. The proposed system recovers waste heat generated during cooling operation through a heat exchanger and reutilizes it for radiant floor heating. The system consists of an air-source heat pump, a refrigerant-water heat exchanger, a hot water storage tank, and a boiler-based radiant floor heating system. A suitable system configuration was developed based on a comprehensive review of previous studies. The cooling control process determines cooling demand based on indoor air temperature and prioritizes waste heat recovery, while the heating control process is designed to prioritize thermal comfort based on floor surface temperature. As a result, four representative operating modes are defined: a simultaneous heating and cooling mode, a cooling-only mode, a heating-only mode, and a non-operational mode. In future work, the proposed system will be implemented in a simulation environment to quantitatively evaluate energy-saving potential and thermal comfort performance under various operating scenarios and climatic conditions.