Numerical investigation on the heat flux properties of a thermal manikin in sleeping environments applying task/ambient air conditioning

• Published in: Journal of thermal analysis and calorimetry Vol. 147; no. 2; pp. 1675 - 1688
• Main Authors: Mao, Ning, Song, Mengjie, Xu, Yingjie
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-01-2022; Springer; Springer Nature B.V
• Subjects: Accounting; Air conditioning; Air temperature; Analysis; Analytical Chemistry; Bedrooms; Chemistry; Chemistry and Materials Science; Control engineering; Convective heat transfer; Energy conservation; Enthalpy; Heat balance; Heat flux; Heat loss; Heat transfer; Human body; Inorganic Chemistry; Investigations; Latent heat; Measurement Science and Instrumentation; Microclimate; Physical Chemistry; Polymer Sciences; Posture; Radiative heat transfer; Thermal comfort; Convective heat transfer; TAC system; Thermal comfort; Radiative and evaporative heat loss; Body heat loss; Sleep environment
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-020-10515-2

As an energy-saving equipment, task/ambient air conditioning (TAC) system was widely used in sleeping environment in recent years. The TAC can deliver cooling air directly to the sleeping person, resulting that the micro climate around the human body becomes very critical in the evaluation of human beings’ thermal comfort. Different from sitting and standing, sleeping human body is always at lying posture, and thus at a lower metabolic rate than at waking status. To understand the heat balance between a sleeping body and the surrounding environment, investigation on the heat loss of human body becomes necessary. Hence, a numerical study on the body heat loss characteristics of a thermal manikin at sleeping state in a bedroom utilizing a TAC system was carried out. The convective heat transfer, radiative heat transfer, evaporative heat loss from skin and respiratory heat loss and their ratios were quantitatively analyzed. The results indicate that the convective heat transfer took the first place, accounting for about 80% of the total heat loss, and Latent heat loss accounted for 15.9%–21% of the total heat loss. In addition, the heat loss at different supply conditions was numerically studied. Results showed that the supply air temperature, flowrate and humidity play different effects on body heat loss. Contributions of this study are meaningful for the accurate control of micro climate of human activities.