Use Side-Supply Airflow to Enhance Heat Transfer of Radiant Heating Ceilings for Producing a Better Indoor Thermal Environment in Winter: A Simulation Study

Radiant cooling/heating systems have advantages of high-comfortability and energy-saving, whereas a certain building usually adopts one type of radiant surfaces (e.g., only radiant ceilings) rather than two or more simultaneously to save initial investment. Radiant ceilings are a kind of common-used radiant systems, which has been widely demonstrated to be effective in summer. While in winter, radiant heating ceilings mainly heat the upper body parts of occupants and the warm air still stays in the upper space of a room. The aim of this research is to produce a better indoor environment of a room with radiant heating ceilings by using side-supply airflow. Four typical conditions were selected to be simulated with ANSYS Fluent. The obtained result showed the system had more uniform air temperature and the air velocity level of was below the 0.2 m/s in most of the occupant zone when two-side-supply airflow and radiant heating ceilings were used simultaneously. In addition, it could create a superior indoor environment by increasing air temperature and reducing air speed.