Carbon Dioxide Levels and Ventilation Rates in Schools

In the following, measurements of CO2 levels in seven classrooms in four schools are reported. Measurements were taken for approximately one week in each classroom during the heating season and the time-varying ventilation rates estimated. The results of the experiments show CO2 concentrations which are far beyond the guideline value of 1000 ppm (the average concentration during the occupied period was 1957 ppm). In some classrooms the level exceeded the range of the detector (4000ppm).

Experimental and numerical studies on air diffusion in a single office

The study has compared experimental data and numerical simulation of air velocity for a room with jet diffusers to assess comfort conditions in the occupied zone. Comparison was mainly done in planes perpendicular and along the jet axis.Results allow to expand the use of the numerical approach during design to achieve high levels of environmental comfort.

Influence of furniture layout and ventilation design on air quality and thermal comfort

The study presents the influence of three different air diffusion systems and furniture layout on comfort (PMV, PPD) and indoor air quality (ventilation efficiency). Results of CFD calculations have been validated using experimental results for one case on a test rig. Charts are given to help dimensioning.

The evaluation of multi-zone air flow pattern and ventilation rates with tracer gas methods in appartment house

Detailed testing of multi-zone airflow and ventilation rates in a dwelling were conducted using two different types of tracer gas method and compared with design.

Tracer gas techniques for measurement of ventilation in multi-zone buildings - a review

Five different techniques of tracer gas measurement are reviewed in order to determine the total ventilation airflow rate as well as air distribution in the room, on site or in laboratory. Examples of applications are given insisting on the two most recent techniques.

An examination of the influence of various effects on room air flow

The study examines the effect of diffuser, buoyancy and surface radiation on flow, in order to better understand the changes in room air flow due to the energy control strategy. Calculations have been applied on one room for two different ceiling air diffusers.

Study of indoor air quality air flow pattern in a room with floor heating

Airflow patterns, temperature and indoor air quality (ventialtion efficiency) are modelized in a room with floor heating. Results show that ventilation efficiency depends directly of diffusers layout.

Computation of airflow in a displacement ventilation/chilled ceiling environment

This study is to validate a CFD model of displacement ventilation combined with chilled ceiling and determine if this combination may create draught risk or influence badly indoor air quality.

Assessing multi-zone airflow simulation software

Several standard multizone modeling programs, in order to improve their computational efficiency, make a number of simplifying assumptions. This paper examines how those assumptions reduce the solution times and memory use of the programs, but at the cost of restricting the models they can express.

Impact of the urban pollution on the indoor environment - experimental study on a mechanical ventilated dwelling

Measurements were carried out to assess the transfer of outdoor air pollution (CO, SO2, NO, NO2, O3, BTEX, TVOC, fine particles, smoke index) into an unoccupied and empty dwelling in Paris, in winter and summer. The controlled air exchange rates were 0.6 and 0.9 volume/h. Some pollutants have a reduced concentration indoors (NO, SO2, O3, particles, smoke index) as others are transferred (like CO). Some results were also obtained with sorbing materials inside the dwelling, which reduce indoor concentrations.

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