Most of humans’ lifetime was spent indoor, especially in bedroom. Thus, understanding the characteristics of the sleep microenvironment is a prerequisite for better control and improvement of our sleeping environment. This study investigated the temperature and velocity field above the heads of sleeping people with supine postures, and explored the interactions between the thermal plume and the breathing airflow, where both the thermal manikins and real human subjects were used in our experiment settings. Three different breathing modes were considered in this study, where the non-breathing mode was used to investigate the characteristics of the thermal plume, and the synergy of the mouth and nose breathing mode on the thermal plume was also investigated. The results showed that the thermal plume of a supine posture person was not strong compared to that of a standing or sitting person, and the breathing airflow could influence the development of the thermal plume. Over the head of a sleeping person, the velocity of the thermal plume could be increased by both of the breathing modes, but no significant difference in the velocity and temperature field was found for the two breathing modes. It was also found that pollutants near the bed surface could be brought to the breathing zone with low velocity airflow, but could be blocked by the nasal exhalation jet. The findings in this study could provide theoretical support and guidance to improve the air quality in the breathing zone.

人类一生的大部分时间都是在室内度过的，尤其是在卧室里。因此，了解睡眠微环境的特点是更好地控制和改善我们的睡眠环境的前提。这项研究调查了仰卧位睡觉的人头顶上方的温度和速度场，并探索了热羽流和呼吸气流之间的相互作用，在我们的实验环境中使用了热人体模型和真人受试者。本研究考虑了三种不同的呼吸模式，其中非呼吸模式用于研究热羽流的特性，并研究了口鼻呼吸模式对热羽流的协同作用。结果表明，与站立或坐着的人相比，仰卧位的人的热羽流并不强，呼吸气流会影响热羽流的发展。在睡眠者的头顶上，两种呼吸模式都可以增加热羽流的速度，但两种呼吸模式的速度和温度场没有显着差异。还发现床面附近的污染物可以被低速气流带到呼吸区，但可以被鼻呼气射流阻挡。本研究结果可为改善呼吸区空气质量提供理论支持和指导。在睡眠者的头顶上，两种呼吸模式都可以增加热羽流的速度，但两种呼吸模式的速度和温度场没有显着差异。还发现床面附近的污染物可以被低速气流带到呼吸区，但可以被鼻呼气射流阻挡。本研究结果可为改善呼吸区空气质量提供理论支持和指导。在睡眠者的头顶上，两种呼吸模式都可以增加热羽流的速度，但两种呼吸模式的速度和温度场没有显着差异。还发现床面附近的污染物可以被低速气流带到呼吸区，但可以被鼻呼气射流阻挡。本研究结果可为改善呼吸区空气质量提供理论支持和指导。还发现床面附近的污染物可以被低速气流带到呼吸区，但可以被鼻呼气射流阻挡。本研究结果可为改善呼吸区空气质量提供理论支持和指导。还发现床面附近的污染物可以被低速气流带到呼吸区，但可以被鼻呼气射流阻挡。本研究结果可为改善呼吸区空气质量提供理论支持和指导。