Anna Bogdan, Kacper Ogłodziński, Mirosław Szyłak-Szydłowski
Thermal plumes generated by a human being are elements that influence the shape of air flows in a room, mainly when displacement ventilation is used. The characteristics of the airflow in these plumes are usually studied using thermal manikins, which has many advantages during the research of thermal man-environment interactions––owing to the repeatability of tests, lack of fatigue, or taking into account individual human characteristics. However, under actual conditions, thermal plumes are generated by real people, who may move slightly, breathe, and have different body surface shapes and thermoregulatory system reactions. Therefore, this study aimed to evaluate the thermal plumes formed over human subjects in an environment typical of office spaces. The study was carried out under conditions of a moderate environment, with men of similar body build, wearing clothes with similar heat insulation, and in a sitting position. The study confirmed that when simulating this process with thermal manikins, it is necessary to get as close as possible to the conditions in which the future occupants of the rooms will be in––as the air velocity values measured over the volunteers are generally lower than the air velocities measured in the study using thermal manikins. It is also necessary to start the thermal manikin breathing process; however, this should be conducted carefully. This significantly affects the obtained results of the air velocity in the thermal plumes and may generate overestimated results.