Radiant split for the internal heat gains in buildings with radiant cooling systems

In buildings with radiant cooling systems, the presence of activated radiant surface has changed the building thermal dynamics, including the radiant split of the internal heat gains. However, in current building cooling load calculations and energy consumption simulations, there is a lack of study on the radiant split of the internal heat gains for radiant cooling systems. In this study, we established a CFD model to calculate the radiant split. A comparison between all-air and radiant system shows that the radiant split is 3~11% larger in rooms with radiant system. Afterwards, we selected six possible impact factors on the radiant split. The results show that radiant split increased by 5.6~8.2% in rooms with radiant systems. Besides, building envelope type and internal heat source emissivity impact radiant heat gain split significantly.