Details

Autor(en) / Beteiligte

• Zhou, Xiang
• Liu, Yunliang
• Luo, Maohui
• Zhang, Lili
• Zhang, Qiqi
• Zhang, Xu

Titel

Thermal comfort under radiant asymmetries of floor cooling system in 2 h and 8 h exposure durations

Ist Teil von

• Energy and buildings, 2019-04, Vol.188-189, p.98-110

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •We studied thermal comfort effects of radiant asymmetries under 2 h and 8 h exposures.•We found floor cooling systems are easier to have discomfort complaints.•Exposure duration has significant impacts on thermal comfort responses.•Two satisfaction equations are developed for floor cooling considering exposure time.•Floor cooling temperature limits are > 18.5 °C and > 20.5 °C for 2 h and 8 h exposures. Radiant heating and cooling systems inherently exhibit radiant asymmetries. Although many researchers have investigated the thermal comfort effects of asymmetric radiant environments, the exposure duration has not been emphasized, especially under floor heating and cooling scenarios. In this study, we conducted a series of tests in a climate chamber with floor cooling radiant asymmetries with human participants to investigate their thermal comfort effects from short-term (2 h) and long-term (8 h) exposure perspectives. The 2 h exposure test indicates that the floor cooling systems cause discomfort complaints more easily than other radiant systems such as ceiling heating/cooling because of its stronger cooling effects on the lower body parts. The cold floor resulted in significantly colder local thermal sensations and lower local skin temperatures in the foot, calf, and thigh areas. The comparison between the 2 h and 8 h exposures suggests that exposure duration affects both the subjective and physiological thermal comfort responses significantly. 2.5∼4 h are required for the foot and calf temperatures to stabilize in radiant floor cooling asymmetry cases. In accordance with these laboratory tests, we proposed two radiant asymmetry-satisfaction curves and equations for the floor cooling system with consideration of exposure duration. The calculated temperature limits for typical floor cooling room are >18.5 °C at a 2 h exposure and >20.5 °C at an 8 h exposure. These curves and temperature limits can serve as a reference for future guidelines for floor cooling system design and operation.