This study is an analysis of equivalent temperature in its role as an evaluation index used when measuring thermal comfort inside cars. In this report, a new equivalent temperature was deduced by considering the actual heat movement from the body to the environment. This equivalent temperature reflects the convection heat transmission rate, the radiation heat transmission rate, and the kinds of clothing surrounding the human body. The study also clarifies an internal structure of the coefficient that hangs in the constant value and 3 treated paragraphs in equivalent temperatures as outlined by Madsen. After analyzing a range of applications for this equivalent temperature and its effectiveness it is possible to confirm that there is no great difference from other equivalent temperatures as long as it is used within certain environmental parameters.

抄録全体を表示

The clothing area factor (f_cl) is defined as the ratio of the clothing surface area to the body surface area. It may play an important role in analyses of heat exchange between the clothed body and the surrounding environment. For practical purposes it has commonly been estimated from a function of clothing insulation although clothing fit is a determining factor in estimating clothing surface area. The significance of clothing fit on f_cl was demonstrated by Kakitsuba et al. (1987).
In this study, f_cl was derived by a photographic method using a 180° OP fish-eye lens camera as used in the previous study. Clothing microenvironment volumes (V_μ) were measured by two different methods, i.e., a method of measuring the thickness of the clothing microenvironment, and a silhouette method. Subjects wore everyday clothing ensembles: one was relatively tight-fitting and the other was loose-fitting. The f_cl values and V_μ were measured with the subjects standing, sitting on a chair, and sitting on the floor. In addition, the subjects' body volumes (V_b) were estimated from anthropological measurements.
The results showed that the f_cl values varied between 1.05 and 1.31 and were not in accordance with clothing insulation, for which values were consistent (the mean=0.52 clo), and that the f_cl value can be defined as a function of V_μ/V_b.

抄録全体を表示

It is common practice to parameterize urban canyon geometry as a sky view factor to be used to estimate surface radiation budgets. However, it is found that existing techniques of the computation of sky view factors are tedious, time consuming, erroneous and has often limited to just a few study cases. A fully automated digital approach to calculate sky view factors from fisheye photos is presented here. The validity of the new automated technique was tested by a series of inter comparison with other manual methods, which produces nearly identical results. The technique was applied in real conditions and it was found that increased sky obstruction significantly decreases the loss of long wave radiation in the nighttime and thus affects cooling rates.

抄録全体を表示