The Real Life Efficiency of Gas Phase Filters Used in General Ventilation and their Influence on the Indoor Air Quality of an Office Building

Gas phase filters have been installed within the air handling unit of an HVAC system feeding 100 %fresh (outdoor) air to an office building. The filters efficiency for ozone (O3) and nitrogen oxides (NO2and NO) has been measured continuously over a one year period as function of time and outdoor airparameters (temperature, relative humidity). The results show that the filters efficiency varies alongtime and depends on temperature and relative humidity of air.

Air quality measurement in a model kitchen using gas and electric stoves.

Epidemiological studies suggest that cooking with gas leads to an increase of air pollutants and may enhance symptoms of respiratory diseases. However, little experimental data are available concerning the emission of pollutants due to different cooking processes. The goal of this study was to investigate the influence of cooking under standardized conditions on the indoor air quality. A model kitchen was built and three different gas stoves and one electric stove were included in the study. Two different menus were prepared with different settings of the ventilation rate of the exhaust.

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

We studied the effect of ventilation and air filtration systems on indoor air quality in a children's day-care center in Finland. Ambient air nitrogen oxides (NO, N02) and particles (TSP, PM10) were simultaneously measured outdoors and indoors with automatic nitrogen oxide analyzers and dust monitoring. Without filtration nitrogen oxides and particulate matter generated by nearby motor traffic penetrated readily indoors. With chemical filtration 50-70% of nitrogen oxides could be removed. Mechanical ventilation and filtration also reduced indoor particle levels.

Infiltration of VOCs from outdoor air: an indoor-outdoor comparison.

The indoor-outdoor comparison of volatile organic compounds was made in 52 private homes in the City of Munich, Germany. The VOC concentrations were measured by trapping with activated charcoal tubes and analyzed by capillary GC. The infiltrated NO, was monitored in the indoor air. It can be concluded that the benzene concentration in the indoor air is controlled by the outdoor concentration for approximatively 30 % of the investigated cases.                

Nitrogen oxide emissions from unflued space-heaters.

Measurements of the levels of nitric oxide and nitrogen dioxide emitted by radiant and convective space heaters revealed that the NOx emitted by the former was mainly NO2 while convective heaters produced mostly NO. As the air became vitiated, however, the convective heaters began to produce more NO2than NO. This evidence confirms that the nature of the NOx produced by a nunflued room heater depends on the type of heater and the conditions under which it operates.

Environment and Power: Home weatherization and indoor air pollutants.

A booklet for consumers explaining the effects of house-tightening measures on pollutant levels. It also provides a guide to detecting and controlling pollutants commonly found in homes.

Environment and Power: Energy efficient new homes and indoor air pollutants.

This booklet for consumers discusses what indoor air pollution is and how it can affect health. Ways of reducing pollutant levels are summarised

Indoor air pollution and housing technology.

Reviews the scientific literature on indoor air pollution. Low-pollution design and construction techniques employed in the Sunnyhill Low-Pollution Research Centre are outlined in detail and suggestions are made on their applicability to new and existing housing in Canada. The study recommends a four-fold approach to the indoor air pollution problem by government and the building industry: A) short-circuit major potential hazards, B) deal with low-pollution housing needs, C) spread and apply present knowledge, and D)foster more research and discussions on regulation.