The impact of air pollution from used ventilation filters on human comfort and health

In an environmental lab with a panel of 30 women exposed 4 hours, comfort and health have been detremined both with a used or a new filter present in the ventilation system. All other environmental parameters were kept constant. A used filter in a HVAC system can have a negative effect on both the immediate perception of the indoor air quality and on perceptions and health-related symptoms. However, the annoyance experienced through the sensory system may have amplified the intensity of symptoms.

Isothermal airflow in a gymnasium studied by numerical and full-scale experimental methods

CFD simulations and measurements were used in isothermal air-conditioned space of a gymnasium. Different airflow patterns due to different supply air were simulated. Results obtained are correct considering the complexity of boundary conditions.

Development of a measurement method for air current by the use of balloons for gravity free

Design of thermal and air environment for large spaces is often realised with CFD simulations but due to measurement difficulty there are few cases in which results are compared after construction. This study uses a simple method for visualizing air currents and for estimating distribution of air movements with balloons.

The impact of tracer gas mixing on airflow rate measurements in large commercial fan systems

The study characterised the mixing of tracer gas in three ventilation systems with two different airflow rates (totally outdoor air).The test procedure is presented and errors are calculated and compared.

The simulation of ventilation of entrance atrium in the Moravian library

The Moravian library's atrium in Brno (Czech Republic) is eight stories high. Ventilation is a combination of mechanical supply by nozzles in each gallery and a natural stack effect in the atrium from bottom to top. CFD has been used for design.

Carbon Dioxide Levels and Summertime Ventilation Rates in UK Schools

Measurements of metabolic carbon dioxide concentration made in four classrooms in two schools are reported for both occupied and unoccupied periods. Measurements were taken for approximately one week in each classroom during the unheated season and the time-varying ventilation rates estimated. The results of the experiments show CO2 concentrations that are far beyond the guideline value of 1000 ppm (the maximum concentration during the occupied period was 3756 ppm). Calculated air supply rates vary from unacceptably low levels, to rates that are in line with guidance.

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.

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