AIVC - Air Infiltration and Ventilation Centre

Search form

EBC

You are here

Home

outdoor air

Exposure to varying levels of contaminants and symptoms among workers in two office buildings.

The outdoor air supply was manipulated over a period of six week in two mechanically ventilated offices in Montreal, and symptoms and environmental parameters noted. Higher dust and higher nitrogen dioxide concentrations led to eye symptoms reports. Higher TVOCs were associated with mucosal symptoms. Higher dust levels were associated with systemic symptoms.

Penetration of nitrogen oxides and particles from outdoor into indoor air and removal of the pollutants through filtration on incoming air.

A children's day care centre in Finland was the site of a study on the effect of ventilation and air filtration systems on indoor air quality. Indoor and outdoor concentrations of NO, NO2, TSP and PM10 were measured using automatic nitrogen oxide analysers and dust monitoring. Nitrogen oxides and particulate matter from traffic penetrated easily in the absence of filters.50%-70% of nitrogen oxides were excluded with chemical filtration. At holidays and weekends, the particle levels fell less than 10% of the outdoor level, rising to 25% on weekdays.

Measurement and impact of outdoor air supplied to individual office building occupants on indoor air quality.

Describes a new method used to measure the amount of outdoor air supplied to individual building occupants, under field conditions. The method includes factors associated with office design. It is based on the measurement of the constant release of tracer gas into the outdoor air in the ventilation system. The obtained values are termed outdoor air supply indexes (OASIs). States that the type of diffuser, office, partition and return air inlet and their position relative to each other can have a considerable effect on the amount of outdoor air received at individual work stations.

Indoor and outdoor air quality investigation at 14 public places in Hong Kong.

An investigation was performed on the indoor and outdoor air quality of fourteen public places in Hong Kong with mechanical ventilation. They included restaurants, libraries, recreation places, shopping malls, sports centres and a car park. Pollutant concentrations were measured during peak traffic hours at each sampling location. States that the results showed that the indoor/outdoor ratios at public places were higher than those at home and offices.

Research of fractal and chaotic characteristics on room airflow and outdoor airflow.

As researches on air delivery to air-conditioning room are turning from static mode to dynamic mode, especially the natural airflow simulation plan is being put forward, these, in turn, require more thorough understanding and more effective evaluation method of various airflow turbulence patterns. On the basis of large amount of carefully controlled measurements of air velocities which are generated in air-conditioning room, outdoor and by local fan, a detailed calculation and analysis has been made in the light of the rapidly developing nonlinear science - chaotic theory.

Concentrations and sources of volatile organic compounds in urban domestic and public microenvironments.

Considered a wide range of indoor and outdoor urban microenvironments in a study of the concentrations of 15 volatile organic compounds. For most VOCs, mean concentrations in cars exceeded those at heavily trafficked roadside locations. No correlation was found between indoors and outdoors, though concentrations were higher indoors. As a consequence, in poorly ventilated buildings, indoor emission source strength is considered a more significant influence on concentrations of VOCs in indoor air than outdoor air concentrations.

Experimental study on the impact of ventilation parameters on pollutant transfer from outdoor air into a dwelling.

In urban areas, people stand the most of their time in indoor environment. In this context, indoor air quality is more and more a subject of concern. Outdoor air quality can have a large impact on indoor air quality. An experimental study has been conducted into a dwelling, in collaboration between the LHVP and the CSTB, in order to study the indoor concentration of pollutants depending on the outdoor pollution and the air renewal due to ventilation system. Different experiments have been conducted in an empty dwelling situated in a polluted area in Paris during winter and summer periods.

External influences on indoor air quality.

Outlines a project to promote greater consideration of indoor air quality during building design. The project was commissioned to develop guidance on assessing the overall external pollution burden on a building and techniques for minimising indoor pollution from external sources. The guidance focuses on non-domestic buildings. It is nearing completion and is based on three main groups of pollution sources - long-range, intermediate-range and short-range.

Investigating IAQ complaints after renovations at an office building in New York City.

Describes an investigation of the indoor air quality of a music company at their New York City office. The office was on the 31st floor of a block. Recommendations for producing better IAQ were as follows: 1) Recalibrate return airflows where needed to harmonise them with the values specified in the HVAC system design. At the same time verify and adjust airflows from the supply-air diffusers. The amount of outdoor air should comply with the ASHRAE Standard 62.1-1999 industry guideline of 20 ft2 per person per minute in offices.

Comparison between indoor and outdoor air contaminant levels in residential buildings from passive sampler study.

The article discusses relationships between indoor and outdoor levels of various air contaminants (nitrogen monoxide, nitrous oxides, sulphur dioxide and ozone), in ten non-smoking residential buildings in Hong Kong. The experiment used passive samplers. Estimated the source and sink strengths of the contaminants, applying an integral approach to the mass balance equation. The results indicated that the buildings acted as sinks for the contaminants. When compared to the newly developed indoor air quality guidance notes in Hong Kong, the nitrogen oxides level gave some cause for concern.

Pages