A seated, unclothed and bald manikin is used for the experiment. A numerical method calculates the view factors between individual segments of a thermal manikin , and between the outer surfaces and the body segments. The segment to segment radiation is the subject of the research : radiation between segments may be significant and the local differences in radiative heat loss may cause discomfort and cannot be ignored.
This study makes clear that mean skin temperature and skin wettedness do not remain constant but may vary under constant thermal sensations of "slightly warm", "warm" and "hot". The relationship between mean skin temperature and skin wettedness under the constant thermal sensation of "warm" is adequaltely expressed through a convex curve with a negative slope.
This study is divided into 2 parts : 1. Discussion of the theory of a measurement method for configuration factors using reflections of a curvilinear mirror.2. Estimation method of configuration factors for medium/large scale spaces that can be used instead of methods using the diagrams.
The study was carried out on 6 subjects. Each one is seated at a desk with a mounted PVS. During the experiment the room air temperature was controlled at 28C and the personalized air temperature was 25C. Several fluctuations were tested, air movement with a frequency of 0.2 Hz was preferred to 0.1 Hz and 0.3 HZThe subjects had a preference for a lower mean air velocity but were more distracted when air movement fluctuated (0,2 Hz) than when it was constant.
For that study, 40 subjects were exposed to controlled air movements ( slightly cool, neutral, slightly warm thermal sensations at 18 °C, 20°C, 23°C, 26°C and 28°C). Their responses were collected. Results indicate that air movement preference depends on
The authors introduce a new airflow characteristic, the equivalent frequency, as an integral measure for the frequency of the random velocity fluctuations in rooms. The aim of that study was to test the impact of the equivalent frequency on draught sensation for human subjects. Further investigation at different air temperatures along with different turbulence intensities of air velocity is recommended.
For that study , an heated manikin, in a seated position, is exposed to a local thermo ventilator that promotes a non-uniform horizontal flow ( front , behind and right side) ; an interior climate analyser measures the environmental variables around the manikin. Those data are used as inputs of the numerical program.
A numerical model simulates the human and clothing thermal systems and evaluates the thermal comfort level. Verification was made that when the ventilator is places in front of the manikin, acceptable thermal comfort conditions are fullfilled.
This paper reports a large-scale investigation result on seat occupancy rate in a typical Japan office with 240 workers. The experiment lasted 3 months. The sensing device continuously recorded the seating status for about one week for each working person. From these results , a practical use situation of the personal air-conditioning system in the office could be predicted.
CFD is used to simulate the effects of respiration in displacement ventilated rooms. It was done in a satisfactory manner.An extra simulation was carried out with "density-corrected" exhalation temperature, to see if the results are sensitive to variations of this parameter. This proved not to be the case. The choice of the flow rate is more important for the flow pattern.
The aim of that study is to make a database of the local convective heat transfer coefficients for each part of a human body in sedentary and standing environments through the use of an experimental thermal manikin and an analysis of the radiative heat transfer rate. The results are applicable to both indoor and outdoor environments.
The paper also discusses the influences of wind velocity, sensible heat loss, posture and furniture arrangements on local convective heat transfer coefficients values.