Flow characteristics of a local exhaust system

This paper presents the study of a local exhaust ventilation system with plain (unflanged) and flanged hoods. Centerline velocity and velocity contours in front of exhaust hood openingswere measured and compared to other previously reported results. Centerline velocity correlations are derived for a full range of hood axes. The effect of turbulence intensity and surrounding equipment on the velocity contours is also analyzed. Capture velocity for three different types of contaminant particles (saw dust, wheat flour, and sand) was determined.

CFD analysis of ventilation system performance for enclosed parking garages

In this paper, a CFD analysis of airflow and contaminant distribution within enclosed vehicular parking facilities is presented. First, the CFD simulation is validated using field data. Then, the results of a parametric CFD analysis are summarized. In particular, it was found that significant fan
energy savings can be obtained when simple on-off controls are properly implemented without affecting the indoor air quality within the garage. Moreover, it was found that the position

Planning of ventilation for a large parking space by using temperature difference

We designed a roofed parking lot for a large wholesale market in Sapporo City to protect trucks and cars from snow and rain. Every day, the area attracts a large number of vehicles including trucks. Drivers often leave the engines running for heating in winter and cooling in summer. Exhaust gases poison the air, creating a serious environmental problem. The roof of the new parking lot is equipped with two kinds of chimneys, such as high chimneys to exhaust waste air and low chimneys to supply fresh air.

Measurement of the air quality in hospitals Messung der Luftqualität im Krankenhaus

This article shows results of air quality measurements (airborne moulds, microbes and particles) operated in summer and winter in an hospital in Japan.

The effect of external conditions on indoor air quality in new buildings

The development of indoor air quality was studied in three newly finished buildings in Helsinki, Finland during the years 2000-2002. The concentration of volatile organic compounds (VOC), formaldehyde and ammonia, for which the Finnish Classification of Indoor Climate 2000 gives target values, in indoor air as well as the air exchange rate, relative humidity and temperature were determined for the newly finished buildings and 6- 12 months after the buildings had been taken in use.

Indoor environmental exposures and symptoms

It is a basic biological truth that people bring different levels of responsiveness to irritant stimuli to work. No one reacts to the same levels with the same intensity (symptoms are different)What are the stress factors that lead people to complain? Poor work organization, inadequate communication or pollutants ? The author suggests that priority should be given to the problems of work organisation before looking for problems of indoor air pollution, air-handling, or heating.Systematic approaches to stress management have shown to have major benefits.

Impact of varying area of polluting surface materials on perceived air quality

The impact of the concentration of pollutants in the air on emissions from building materials is the subject of that study.Different building materials were studied in ventilated small-scale test chambers. The experiment allowed the changing of the dilution factor or the changing of the area factor.The results showed that more ventilation in a given space may increase the emissions from the inner surfaces.

Control strategies for sub-micrometer particles indoors : model study of air filtration and ventilation

A good indoor air quality is necessary to minimize exposure to airborne pollutants. The main source of those pollutants is often outdoor air. Ventilation and air filtration are the main solutions to reduce them.The aim of that study was to investigate the effects of air ventilation and filtration on submicrometer particle concentrations indoors thanks to a simple one zone mathematical model that simulates the time evolution of particle concentrations indoors.

Air quality in a simulated office environment as a result of reducing pollution sources and increasing ventilation

That study aims at proving that the use of low-polluting building materials leads to an improvement of the air quality. For the experiment the space of an office qualified as low polluting has been altered by introducing indoor pollution sources (such as linoleum, wooden shelves, books and paper documents) and an outdoor air supply rate altered too. The concentrations of VOCs were measured in those different conditions along with the perception of the air quality assessed by a panel of 30 female subjects.