Thermal comfort examination in a room having a radiant-cooled wall and a slot diffuser ventilation system

Radiant systems provide efficient cooling throughlarge heat transfer areas, but their evaluation should include ventilation to ensure sufficient thermal comfort. In this study, a hydronic cooled left wall having cooled water was examined in a 1.8 m × 1.8 m × 2.7 m enclosure with 15 × 15 cm2 baseboard-level air channels on three sides operates combined or separately as a rare experimental study due to the insufficient number of study in available literature. While radiant panel inlet water temperatures were 12.9, 13.9, and 14.9°C, supply air was blown in various diffuser configurations having velocities of 5 and 10 m/s. PMV, operative temperature, turbulence intensity, draft rate, and vertical temperature difference have been examined. Consequently, all calculated PMVs and operative temperatures met ISO 7730 comfort standards, with the lowest turbulence intensity and draft rate values recorded from the left and middle diffusers. When the air was blown from the right diffuser and through all diffusers at 10 m/s air velocity, separately, operative temperatures were 22°C, negative PMV, and above 50% draft rate existed. Besides, maintaining high air velocity lowered thermal stratification, lowering vertical temperature difference below 0.5°C. Therefore, high air velocity negatively affects local comfort by increasing PMV values, thermal homogeneity, turbulence, and draft.