In this paper the author relates his experiment : while interviewing unhappy building occupants he realized that it was necessary to step back from the specific complaints and begin with the basics of proper ventilation, moisture control, temperature control before embarking on costly scientific investigations to solve the problem.
An optimal placement of outside air intakes is important for a good IAQ protection. A proper intake placement can also reduce the need for filtration, and reduce re-entrainment of chemical emissions.
The microbiological quality of air was studied in a bread-making factory (100t/day). It wasnoticed that the microorganism density varies along the fabrication hall, a high number of microorganisms, especially moulds, being registered in the bread cooling area and the storage room. In the bread cooling area predominate Penicilllium expansum spores, this mould being able to develop at low aw values and determining the bread spoilage.
Subjective experiments were conducted during the summer season and the winter season in order toclarify the multiplied effects of humidity and indoor chemical pollutants on subjective comfort and productivity. Lower concentration of formaldehyde was observed at low humidity than at high humidity. Subjects rated the acceptability of air lower at the beginning of the exposure in the environments polluted with formaldehyde. On the other hand, lower humidity caused subjects to rate air quality higher in clean air.
The IAQ characteristics and the corresponding health symptoms and thermal sensation of the occupants of child care centers in Singapore under 3 different ventilation strategies are reported. The 3 child care centers studied were centrally air-conditioned and mechanically (ACMV) ventilated (Case A), naturally ventilated (Case B) and hybrid (natural and air-conditioning) ventilated (Case C).
Experiences from cleanroom installations has frequently shown that displacement ventilation has a much higher efficiency than mixing ventilation with respect to particle and CO2 reduction, cooling efficiency etc. Another cleanroom experience is that low particle concentration benefits asthma and allergy sufferer. Low particle concentrations reduces the impact of other pollutants and enhance the quality of life for everybody. In an office, the level of discomfort this means less tiredness, better concentration and lower absenteeism.
Nowadays, the need to keep indoor air quality under control is widely known due to the fact that people spend most of their time indoors. In order to show a useful working-tool this paper aims to present a guide to evaluate indoor air quality. This work was structured in the following stages: visual inspection, check list, data analysis, experimental measurements of the physical and chemical pollutants and an analysis of the improvement of indoor environmental quality.
Thermal sensation of tropically acclimatized subjects performing sedentary tasks under personalized ventilation (PV) was explored in this study. The study was conducted in an Indoor Air Quality (IAQ) chamber, which is capable of simulating typical office conditions in Singapore. An experimental design involving interventions in indoor ambient temperature, PV supply temperature and PV supply airflow rate, introduced blind to subjects, was conducted.
Experiments have been carried out to measure unsteady velocity fields near the coughing subject (mannequin) and also understand unsteady transport process resulting from this type of transient flow. Representative human cough waveforms were reproduced using a flow simulator and the measurements were made using Time Resolved Particle Image Velocimetry (TRPIV). Initial high velocity as well as rapid velocity decay with time and distance were observed, and velocity time history and vorticity variations were characterized.
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