Submitted by Maria.Kapsalaki on Wed, 07/02/2014 - 22:00
This study aims to assess the thermal conditions of an indoor environment deemed unacceptable by workers. For this purpose, Ostracon, a voting device, was developed to record the physical environment at the time a worker presses a button to express a complaint. Ostracon was used to record the opinions of 90 workers about their thermal environment in six offices during the summer. The results show that workers found the indoor thermal environment unacceptable even when the static thermal conditions were within a range that was predicted to be comfortable.
Submitted by Maria.Kapsalaki on Wed, 07/02/2014 - 11:58
This research suggests that the thermal preference of occupants is subject to change; hence, a particular thermal setting may not be able to constantly satisfy everyone. On the contrary, individual thermal control in the workplace is more likely to increase user comfort and satisfaction. This is examined through environmental measurements, comfort surveys and semi-structured interviews in two office layouts with high and low thermal control.
Thermal manikin test and subjective experiments with a desktop based task conditioningsystem were carried out in a climate chamber of Kanto-Gakuin University, Japan. Theexperiments were conducted under three different combinations of ambient air temperatureand relative humidity. It was found that skin temperatures at the upper half of the manikinsbody exposed to the supply air were decreased. Setting of task condition was fixed at first, andthen the subjects were allowed to control the environment freely after a certain period in thesubjective experiments.
A validated CFD model was used to generate concentration distribution data for CO2, radon and moisture in a Hong Kong workshop with displacement ventilation.Contaminant concentration distribution depends on the contaminant source type and location. A low concentration may be obtained in the occupied zone when the contaminant source is associated to a heat source whose thermal plume is sufficiently strong to reach the upper zone.
The objective of this paper was to illustrate the potential of the CFD technique to compare the effectiveness of different general ventilation systems in reducing the workers' exposure to styrene vapour in a workroom. . Thanks to the CFD technique predicted airflow velocities and styrene distribution are shown for the 3 different ventilation arrangements at identical planes across the room. And predicted values of styrene concentration at workers'position are given.
For the protection of workers against the excessive radiation heat, local ventilation is used . But the distribution of locally supplied air has to be designed so as not to interfere with the production process. The design of a local air supply ( air shower) is based on operational measurements of thermal conditions realised on the working place of operators.
The analysis of the the operators'heat stress was made by using the WBGT-index (Wet Bulb Globe Temperature index)
The need for control of cobalt from saw filing has been demonstrated by health studies in Finland, Washington state and British Columbia. I am most familiar with the study done in BC, because that is where I live and work. That study was done by a team led by Drs. Susan Kennedy and Kay Teschke, of the University of BC. They observed work activity and measured filers lung function in 8 sawmills, from June to December 1991. They found a high incidence of significantly below normal lung function. Their report was widely and effectively communicated to the sawmill industry.
Occupational hygiene conditions were examined in a welding shop after repairing the air-handling unit. Good indoor air quality was achieved with the new replacement ventilation system. The airborne dust concentrations varied from the detection limit of 0.1 mg/m3 to 0.8 mg/m3 at the stationary sites. Even the breathing zone concentrations of the welders remained below or equal to 2.1 mg/m3. The concentrations of carbon monoxide did not exceed the level of 1 cm3/m3.