A Sonirvey of Wnnnd Speeds Inn Imioor Workplaces
( The applicability of the inhalable convention for sampling aerosols relies on its being a valid model for typical sampling environments. The current convention is based on measurements carried out in external wind speeds between 1 and 4 ms~'. However these measurements show a degree of wind speed dependence, and it is uncertain at present how valid the convention is for describing human aspiration efficiency outside these wind speed limits. Following concerns that wind speeds in many indoor workplaces may be significantly below this range, measurements have been made in 55 work areas covering a wide range of workplaces. Measurements have concentrated on 'background' wind speeds where Hie influence of specific air movement sources is minimised. The pooled wind speed measurements show a highly skewed distribution with an arithmetic mean of approximately 0.3 m*s '. Approximately 85% of all individual measurements were below this mean value. No obvious correlation was found between wind speed distribution parameters and industry type, room size or ventilation type. A limited number of comparisons were made between static anemometers and devices mounted on workers. It was found that modal wind speeds experience by workers were typically 0.05 m-s~' higher than those measured using a static anemometer. These measurements agreed well with previously published data for similar work- places as well as housesJCrown copyright © 1998 Published by Elsevier Science Ltd on behalf of
Aerosol inhalability at higher windspeeds
Abstract The concept and quantitative definition of inhalability (or inspirability) are central to the latest criteria which have been proposed for health-related sampling of aerosols, both in workplaces and in the ambient atmospheric environment. In this paper, the original data from three experimental studies are reviewed in the light of the latest international discussions towards harmonizing the various criteria. A new set of data are also included in the discussion, in which the case of high windspeed, especially relevant to human exposure in the ambient atmosphere, is high lighted. On the basis of the large amount of experimental information now available, it is recommended that whilst the existing inhalability curve (in the form of the inspirability definition proposed in 1985 by the American Conference of Governmental Industrial Hygienists) is adequate at low windspeeds, a modified definition is required at higher windspeed. An empirical formula is proposed that defines inhalability over the wider range of conditions.
Assessment of Ground Regeneration around Borehole Heat Exchangers between Heating Seasons in Cold Climates: A Case Study in Bialystok (NE, Poland)
Based on the experimental studies, the process of ground regeneration around the borehole loaded with brine-water heat pumps working exclusively for heating purposes in the period of four consecutive heating seasons in a cold climate was presented. The research was conducted in north-eastern Poland. The aim of the work is to verify the phenomenon of thermal ground regeneration in the period between heating seasons on the basis of the recorded data and to check whether the ground is able to regenerate itself and at what rate. It was noticed that the ground does not fully regenerate, especially during heating seasons with lower temperatures. In the analyzed period, from 22 September 2016 to 12 October 2020, the ground probably cooled irreversibly by 1.5 °C. In order to illustrate and evaluate the speed of changes in the ground, the one’s profile with an undisturbed temperature field was presented for each month of the year. The presented results can be a very important source of information for the analysis of geothermal conditions occurring in the ground. They can be used to verify mathematical models and conduct long-term simulations that allow us to see the complexity of the processes taking place in the ground.