Abstract Compared with all-air system, the cooling load dynamics for integration operation of radiant ceiling panel (RCP) and dedicated outdoor air system (DOAS) is more complex, and there is a lack of practical cooling load calculation method in current standards and guidebooks. This study aims to explore their cooling load dynamics and develop a simplified calculation method for such integrated system. A heat balance based model to calculate the cooling load for the integrated system was established. The results showed that RCP with DOAS removed more room heat gain than all-air system at the same indoor air temperature set-point, and the peak cooling load of RCP with DOAS is 16% larger. It was also found that ignoring DOAS in cooling load calculation could make the results 6% larger than DOAS integrated. In addition, there is a condensation risk if RCP alone was used to maintain air set-point temperature. To help the application of the integrated system at design stage, we proposed cooling load correction coefficient rrad as the cooling load difference between radiant and all-air system, and the cooling load split fraction rDOAS for DOAS. Through orthogonal screening, 6 significant factors on rrad and rDOAS were selected. Simplified models for rrad and rDOAS calculation in both continuous and intermittent operation modes were established using simulation data, and a revised design process for the integrated system was proposed.