Energy analysis of a hybrid radiant cooling system under hot and humid climates: A case study at Shanghai in China

A conventional radiant panel system offers advantages in terms of energy savings; however, compared with an all-air system, it has limitations such as moisture condensation risk, slow air movement, difficult space zoning, slow air pollutants removal from a highly polluted room, and time delay in start-up of the radiant panel system. This research performs an energy consumption analysis of a hybrid radiant cooling system for buildings in summer. The hybrid radiant cooling system combines a typical radiant panel with a decentralized air convector connected in series. The hybrid radiant panel system generates additional cooling output through its air convector, dehumidifies indoor air, increases indoor air movements, and reduces the time delay in start-up and a filter in the air convector removes air pollutants. This study exhibits the energy performance of the hybrid radiant cooling system compared with an all air system and a typical radiant panel system via numerical modeling using experimental data. This hybrid radiant panel system is effective for energy-saving, because it has a higher cooling impact ratio, and larger coefficient of performance of the chiller, and because the air movement increases the offset effect of the operation indoor temperature rise by an enhanced mixed convection effect. Thus it can reduce cooling energy consumption. The hybrid radiant cooling system can be used very effectively for saving energy in the summer season.