This paper deals with techniques aiming at reducing noise entering into naturally ventilated buildings while reducing airflow path resistance.The description of the combined experimental and theoretical approach is made. A method is suggested to enable the acoustic and airflow performance of apertures for natural ventilation systems to be designed simultaneously.
In experimental chambers, the ventilation effectiveness and thermal comfort of a task ventilation system has been investigated. The method and results of the experiment are presented in this paper. The conclusion of that thermal comfort survey is that task ventilation systems maintain the occupants thermally comfortable while saving energy.
The web-based IEQ survey is a tool that helps assess how well a building is performing from the viewpoint of its occupants. It is useful to detect and solve problems, and to rate a building performance.The survey conducted in more than 70 buildings has been widely tested and refined.
Three case studies are presented, demonstrating the different possible applications of the survey : evaluation of the effectiveness of a technology, information of the guidelines for a new comfort standard, benchmarking facility performance.
This paper describes a study of the relationships between indoor environmental factors and individual work performance in a call center. The productivity benefits of ventilation rates appeared small, for the worker performance, only high temperature had a statistically significant negative impact on productivity. But it appears that the degree of understaffing and shift length have an impact on productivity too.
For that study, 60 person have been tested to compare their response to personalized ventilation and mixing ventilation. The benefits presented in human response were obtained with the personalized ventilation system. The results could be improved with a further development of ventilation effectiveness.
For that study an experiment was conducted during 2 months, in a call center : each week 26 operators returned questionnaires recording their environmental perceptions and sick building syndrome symptoms. In parallel, the recording of their average talk-time was monitored every 30 minutes.The results of that study confirm that increasing outdoor air supply rates and replacing used filters with new ones has a positive effect on health, comfort and productivity of workers.
Reported symptoms from 2000 workers in air-conditioned offices and from 500 workers in natural ventilated buildings have been analyzed using univariate and multiple logistic regression models.The conclusion of that study is that buildings with air conditioning have a higher prevalence of work related upper respiratory symptoms than buildings with natural ventilation though located in tropical country with high relative and absolute humidity rates all around the year.
In this study, serial environmental measurements in 12 large buildings in Taiwan have been made to control the air exchange efficiency on the indoor microbial contamination. High levels of airborne microbes seem to be more easily observed in buildings equipped with fan coil unit system than with air handling unit system.
Adequate filtration of fresh air intake should be imperative to control effectively microbial contaminations of outdoor origin.
In this paper the relation between temperature satisfaction ratings and unsolicited complaint rates recorded in a maintenance database is analyzed. That relationship validates a new method of assessing the economic cost of thermal discomfort in commercial buildings.
That study provides data on compared outdoor and indoor concentration levels of ozone and nitrogen oxides in 8 school buildings in France. It also gives information on the parameters that influence the relationship between outdoor and indoor air quality (such as indoor humidity, indoor temperature, building occupancy, airthightness of the building envelope). Results and discussion are presented.