nitrogen oxides

Describes the monitoring of indoor air quality in a San Francisco office building where occupants had registered eye, nose and throat irritation complaints. Data was taken under two different ventilation rates. Carbon dioxide concentrations increased as the ventilation rate decreased, odour perceptibility increased slightly at the lowest ventilation rate, and other pollutants generally showed very low concentrations, which increased when ventilation was reduced.

Shows that recent investigation has revealed harmful pollutants in greater concentrations in energy-conserving buildings then in the surrounding outdoor air. Some of the pollutants found include particulate matter, carbon monoxide, formaldehyde, nitrogen dioxide and radioactive radon. In the use of some construction materials, measures intended to reduce energy consumption may contribute to the buildup of indoor air pollution. Reviews characteristics of indoor pollutants and major methods of control.

Briefly reviews sources and types of air contaminants common in tight houses. Covers four indoor pollutants - carbon-monoxide and nitrogen dioxide from gas stoves, particleboard plywood and urea-formaldehyde from insulation, and radon from various building materials.Suggests ways of lowering pollutant levels without compromising energy conservation considerations.

In dwellings and similar spaces with limited volume, dilution of indoor air contaminants may be insufficient. The concentration of contaminants in the inside air depends partly on the rate of emission into the room, partly on the ventilation and the concentration of impurities in the outside air. Sulphur dioxide, hydrocarbons, ozone and lead compounds occur in higher concentrations in the outside air, whereas nitrogen oxides, carbon monoxide, benzpyrene (from tobacco smoke), formaldehyde and dust have higher concentrations indoors.

Studies indoor air pollution (and its effect on health) arising from gas cooking. 6-11 year olds from selected primary schools were studied annually from 1973-1977 to see if there was any association between gas cookers in the home and respiration illness.

Measurements have been made of infiltration rates and air leakage characteristics of the building envelope in 38 dwellings all built within the last 20 years and covering a range of construction types. Conventional tracer gas techniques were used (employing nitrous oxide as the tracer) to determine air infiltration rates. Overall leakage characteristics were measured under pressurization using a fan. Some correlation was found between the overall leakage characteristic and the actual infiltration performance of a dwelling.

The primary aim of the project is to describe and document a measurement method suitable for checking whether minimum requirements for ventilation efficiency are fulfilled after a ventilation system has been regulated. The project concentrates on occupied areas with mechanical ventilation such as dwellings,offices and schools. Excludes industrial buildings since special conditions such as ventilation rates, polluting processes and local extraction apply to these. Defines ventilation efficiency, describes equipment and measurement with CO2, N2O, SF6, Kr85.

Reports measurements of indoor air quality in an air conditioned California High School over a range of ventilation rates, ranging from 13.3 cu.ft. of outside air per minute for each classroom occupant to approximately 1.5 cfm per occupant. Parameters measured include outside air supply rate, theoccupants' perception of indoor air quality, microbial burden, concentration of CO2, CO, NOx, SO2, O3 in two classrooms, a hall and outdoors.

Describes Lawrence Berkeley Laboratory's air pollution research project, giving the main goals, parameters to be measured and instrumentation. Describes studies, using an experimental room of 27 cu.m., which measure the emissions from a gas stove operating under air change rates of from 0.25 to 10 changes per hour. Gives graphs of results. Finds that gas stoves generate extremely high concentrations of pollutants when the air change rate is less than one per hour.