The laboratory environment may generate harmful chemical gases, vapors, particulates and biological agents, those substances must be continuously removed from the laboratory. The first section of this paper analyzes the requirements for minimum air exchange in a laboratory, as a result of an extreme situation generated by an accidental spill of a hazardous liquid.The second section studies the level of concentration of flammable chemicals in the exhaust system. An extreme air flow situation is also analyzed.
The objective of the present investigation is to study the potential for both the under-floor displacement and personalized ventilation systems to improve air quality in commercial aircraft cabins.FLUENT was used to simulate airflow in a section of an aircraft cabin with the different ventilation systems : mixing, under-floor displacement, and personalized ventilation.The overall performance of each system was analyzed by comparing CO2 concentration, air temperature, and air velocity distributions.
For that study, the performance of an hybrid ventilation system with a pressure difference sensor in the central exhaust duct has been evaluated through the field measurement. That ventilation system was installed on a detached test house.The infiltration airflow rates of each room were measured by the constant concentration method with SF6 tracer gas. The airflow rate of the exhaust duct was measured by the constant injection method using CO2 gas as a tracer and by the hot wire anemometer.
The method presented in this paper is called DIAGVENT, it was set up by the CETIAT (Aeraulic and air handling technical center) to provide the professionals a practical tool for the diagnosis of the ventilation installations in residential buildings and offices.
It relates the on-site practice, applying a Swedish experience at different French cases .
Three levels of diagnosis are presented :
Diagvent 1 for the checking of the good achievement of the ventilation installations.
This study shows that the removal of combustion products formed during cooking is more efficient in the newer homes than in those studied in the early-to mid-1980s. Realtime measurements were made of CO, CO2, temperature, and water vapor in 74 kitchens in Netherlands. Their inhabitants kept a diary during the measurement period about their cooking and ventilation behaviour, and answered an individual questionnaire too.
In this paper, the authors have studied the oxidation processes on air filter surfaces initiated by ozone. Ozone concentrations were monitored upstream and downstream of used and new filter samples using a small-scale test rig at two different airflows.Test results have shown that the removal of ozone by a loaded filter decreases over time then gets steady. Though necessary, the filtration of ozone creates oxidation processes that are responsible for the generation of products that affect the perceived air quality mainly after periods when the ventilation system is not in operation.
This paper presents the results of an analysis of available scientific findings on how ventilation rate affects work performance. Almost all studies found an increase in performance with higher ventilation rates. The aim was to develop the best possible quantitative relationship between ventilation rate and work performance for use in cost benefit calculations related to building design and operation.
A technique used for the analysis of the contaminant transport in the wake of a bluff body is tested under controlled experimental conditions for application to aerosol transport in a complex furnished room. The authors ' hypothesis is that the dispersion of contaminants in a room is related to the turbulence kinetic energy and length scale. Their approach has been tested both in laboratory and with CFD simulations. Results and conclusions are presented.
In this paper the relationship between air-conditioning energy consumption and the proportion of non-satisfied people in commercial buildings located in Changsha (Hunan Province) is analyzed. Concerning the residentail buildings, the energy consumption and its main influencing factors are discussed too.
The authors think necessary a huge mobilization for everybody takes part into energy saving work.
The aim of this study was to evaluate the association of work-related symptoms, accessed by a standardized questionnaire, of full-time workers from a sealed building, with HVAC system, in comparison with a naturally ventilated building in Rio de Janeiro, a city with hot and humid climate.
The cross-sectional study involved 1,736 full-time office workers of a sealed 42-storey office building and 950 of a non-sealed 14-storey office building, both situated in the downtown area of Rio de Janeiro.
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