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A ventilation cooling shirt worn during office work in a hot climate: cool or not?

Zhao M., Kuklane K., Lundgren K., Gao C., Wang F.

International Journal of Occupational Safety and Ergonomics

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2015

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Vol. 21, No. 4

457--463

EN

The aim of the study was to identify whether a ventilation cooling shirt was effective in reducing heat strain in a hot climate. Eight female volunteers were exposed to heat (38 °C, 45% relative humidity) for 2 h with simulated office work. In the first hour they were in normal summer clothes (total thermal insulation 0.8 clo); in the second hour a ventilation cooling shirt was worn on top. After the shirt was introduced for 1 h, the skin temperatures at the scapula and the chest were significantly reduced (p < 0.05). The mean skin and core temperatures were not reduced. The subjects felt cooler and more comfortable by wearing the shirt, but the cooling effect was most conspicuous only during the initial 10 min. The cooling efficiency of the ventilation shirt was not very effective under the low physical activity in this hot climate.

2

A Body Characteristic Index to Evaluate the Level of Risk of Heat Strain for a Group of Workers With a Test

Lu S., Peng H., Gao P.

International Journal of Occupational Safety and Ergonomics

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2014

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Vol. 20, No. 4

647--659

EN

The purpose of this study was to develop a body characteristic index (BCI) based on the distribution of maximal oxygen uptake per body mass (VO2max/mass), body surface area per body mass (BSA/mass), and percentage of body fat (Fat%) to evaluate the relative level of individual physiological responses to heat strain in a group of workers. BCI was based upon the data obtained from 10 males and 10 females exercising for 60 min on a treadmill at 2 relative exercise intensities of 25% and 45% VO2max in mild, warm wet, and hot dry climate condition, separately. BCI was developed into 2 formulas, which were proved to be better predictors for heat strain responses than each individual characteristic, and more sensitive than body type to describe the distributions of individual characteristics and distinguish the differences in physiological responses to heat.

3

Wybrane aspekty obliczeń wytrzymałościowych komory podgrzewacza oleju

Rusiński E., Czmochowski J., Górski A., Iluk A.

Archiwum Energetyki

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2008

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T. 38, nr 2

175-182

PL

Przedstawiono zagadnienia związane z problematyką wymiarowania komory podgrzewacza oleju wg kryteriów wytrzymałościowych. Podczas projektowania nowego obiektu energetycznego dokonano weryfikacji cieplno-wytrzymałościowej najważniejszych elementów konstrukcji nośnej podgrzewacza. W tym celu głównym zadaniem było opracowanie adekwatnego, numerycznego modelu obliczeniowego ustroju nośnego podgrzewacza oraz zdefiniowanie wszystkich warunków brzegowych zarówno w stanie zimnym jak i gorącym. Jednym z elementów pracy, ze względu na specyfikę obiektu były obliczenia sztywności i stateczności ścian komory. Na podstawie obliczeń : ^prowadzono modyfikacje do modelu wyjściowego. Zamieszczono przykładowe wyniki symulacji ^komputerowych.

EN

In the paper, selected aspects of dimensioning the oil heater by strength criteria are presented. During design process of the heater a thermal and strength verification is conducted. One of the main tasks is the construction of adequate geometrical and discrete models of the support structure of heater and a proper definition of thermal and mechanical boundary conditions for hot and cold states. Local stability and stiffness of heater walls are checked as well. On the basis of calculation some modifications are introduced to the construction of heater and examples of calculation results are presented.