Prediction of human thermophysiological responses during shower bathing

Abstract

This study develops a model to predict the thermophysiological response of the human body during shower bathing. Despite the needs for the quantitative evaluation of human body response during bathing for thermal comfort and safety, the complicated mechanisms of heat transfer at the skin surface, especially during shower bathing, have disturbed the development of adequate models. In this study, an initial modeling approach is proposed by developing a simple heat transfer model at the skin surface during shower bathing applied to Stolwijk's human thermal model. The main feature of the model is the division of the skin surface into three parts: a dry part, a wet part without water flow, and a wet part with water flow. The area ratio of each part is decided by a simple formula developed from a geometrical approach based on the shape of the Stolwijk's human thermal model. At the same time, the convective heat transfer coefficient between the skin and the flowing water is determined experimentally. The proposed model is validated by a comparison with the results of human subject experiments under controlled and free shower conditions. The model predicts the mean skin temperature during shower fairly well both for controlled and free shower bathing styles.

Deriving the operational procedure for the Universal Thermal Climate Index (UTCI)

“…However, the outdoor thermal comfort may also be influenced by the activity level, i.e. metabolic rate (Vanos et al 2010;Kenny et al 2009b), special clothing, as, e.g., required when assessing the thermal load of the working population (Bröde et al 2010b;Havenith et al 2008;Kjellström et al 2009), and by rain and wet clothing Munir et al 2010). Further applications may also aim at providing guidance on the choice of clothing depending on the climatic conditions and activity level (Morabito et al 2008).…”

Phase composition and magnetism of combustion products in Ba–Fe–O compounds synthesized under applied DC electric field

“…In this connection the application of electric fields of various polarities, for example collinear with the direction of combustion wave propagation is an interesting research area. In particular by passing a strong alternating current (AC) through the combustion system it is possible to change significantly the combustion parameters and some of the physical-chemical properties of the synthesized products [9].…”

Integration of Demand Response and Photovoltaic Resources in Residential Segments

“…Moreover, the user switches on the appliance very close to its time of use to minimize heat losses (around 30 Wh per hour, as explained in Section 2.3). Notice that this section estimates that the overall water drawn, according to individual demand of WH, is around 80 L/day and that the system use mixing valves to maintain and limit mixed hot water (temperature X 2 ) to a desired and selectable temperature (for example, during a shower, water flow can get up to 10 L/min of mixed water [71], that is to say, the customer uses approximately 120 to 140 L/day of mixed water). Figure 12 shows the effects of a change in the end-use pattern of WH to achieve the maximum profit from the green energy available (surplus) from the PV array (according to the methodology that was presented in Section 2.4).…”

“…The solution is depicted in Figure 11d: an additional switching-on of the appliance is planned (out of patterns considered by black-box models) for at least 30 min (0.3-0.4 kWh) in the early morning to recover a minimum service during the next shower (see Figure 11c,d, where water temperature grows approximately 3-4 • C with respect to Figure 11b). Notice that a water temperature from 22 to 27 • C is considered cold water [71] and has some effects on the human biology, whereas 28-30 • C is considered a minimum standard of quality for moderately warm water in dermatology. Finally, a new test has been performed through PBLM models.…”