In France, air quality in working areas is a matter of preoccupation for both the industry and the welfare state, that is in charge with the application of the rules and regulations in that field. The Labour Legislation and the Institution of Prevention, bring advice and assistance to the companies and final users.20 practical guides dealing with ventilation are listed at the end of the article.
Three experiments aiming at improving the atmosphere in industrial premices are described in this paper. The working conditions of the staff have been improved along with an amelioration of the process and quality of fabrication.The third example proves that a well adapted technical approach allows the improvement of working conditions coupled with an energy control.
The technical literature very often refers to the international standard ISO 7730. That reference seems to have been accepted too quickly several years ago, without consulting the experts of the profession and without a real critical examination.Now we are facing a difficult situation because the profession recommends (and it is right) temperatures that are lower of several degrees to the ones advised by the standard. Furthermore, an important number of concrete researches demonstrate the very big uncertainties of the data the standard relies on. A serious warning is necessary.
Today the term of comfort includes the different aspects of indoor air quality, thermal, acoustical and visual comfort.Standardisation working groups have already worked in those different fields, and some standards already exist but it will certainly take several years to adapt them according to the countries and continents. Anyway environmental quality is a subjective perception and depends on many interactions. The aim is to insure comfort to the majority of people, but a personal adaptation of the user will always be necessary.
The notion of comfort is not easy to define. As it relies on elements partly subjective, a statistical approach of the user requirements is necessary.In order to reach the optimum reduction of the causes of discomfort, the profession in charge with the indoor air quality has adopted a certain number of rules that working groups of standardization try to improve and complete.
In this paper the author analyses the different weaknesses of the HVAC systems in case of air contamination by a deliberate pollution of the inducted air due to vandalism, terrorism or any other motives.To prevent that danger he gives some advice about HVAC installation :A safe air intake is necessary, but the intake grille for ventilation must be inaccessible from outside the building and its position at ground level unsuitable.Air dampers must have effective sealing and be closed in the event of a bioterrorist attack.Recirculation systems can be contamined too from a source within the bui
A study on the effect of air temperature on productivity was carried out in telecommunications offices with an observational approach in call centre 1 and an intervention approach in the second call center by installing cooling units.The study shows that the productivity can be reduced by 5 to 7 % when the indoor temperatures increase.
A field survey was carried out to evaluate the thermal comfort perception of the occupants of a naturally ventilated public housing in Singapore to find out if that environment meets the Ashrae standard 55's 80 % criteria of acceptability.That survey also examined the adaptive behavior of the occupants in the use of windows, fans, and air-conditioning . Whether the thermal perception was influenced by different sessions of the day, building height and flat types was also part of the study.
This article describes the physical mechanisms leading to broadband noise from axial fans. It gives the results of a literature survey about the semi-empirical correlations available to predict this noise and their application to two examples : a low pressure fan and a high pressure fan.
Dynamic simulation calculations were operated using TRNSYS software applied to a low energy house. This article is the second one of a serie of two. The first one was dealing with ventilation. This one mainly concerns heating system and domestic hot water production through a gas boiler. It also gives general conclusions, some of them dealing with ventilation.
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