air quality

Shows the ventilation of electrowinning cell houses and electrorefineries as being a complex problem. Develops a systematic approach to define the important contaminant generation rates including heat, moisture and acid mist. Discusses fluid dynamic scale modelling as a powerful tool for solving a building's flow field and contaminant concentration field. Examines other associated problems, including wintertime fogging in the building and the high costs of make-up building heat. Presents the possibilities for reclaim of low-grade waste heat, and evaluates the economic impact.

Provides basis for planning and installing plant for maintaining indoor climate based on previous draft which is based on earlier Danish Standard. Refers to several salient design criteria including leakage factors at given test pressure, maintenance of climate parameters, air quality, anticipated energy consumption. Gives example table for requirements of building in terms of m2/person depending on application. States example tolerances of air flows.

Over 200 reports of health hazard evaluations are available of sealed, air-conditioned buildings, requested by occupants who believe their buildings to be hazardous to their health. Describes a computer based building information system developed to extract relevant information about internal environmental measures, disease characteristics and history of occupants, as well as relevant features of the architecture and ventilation conditions of buildings.

Data collected in a LBL study on ventilation in four public buildings includes sensory evaluations of indoor environment and of physical and chemical properties of indoor air. Analyzes database to establish how the indoor odour acceptability criterion (acceptability by 80% of individuals entering theoccupied space) depends on other qualities of the indoor air. Finds that the staleness freshness rating correlates to the odour acceptability better than odour intensity alone. At low concentrations formaldehyde or aldehydes increase odour intensity but also improve odour acceptability.

Looks at ventilation requirements for both odour and physical acceptability and pays particular attention to the differences between smoking and non smoking occupancy in an environmental chamber. Results imply that under non smoking conditions and with moderate humidity, between 5 and 10 cfm of fresh air per occupant should satisfy 75% of visitors, but that under smoking conditions, many times as much fresh air is needed for both odour acceptability and compliance with customary criteria values for smoke.

Air change rate is often reported as a single number, with no attention paid to different values of air change rate in different zones of a building. This may affect air quality evaluation as there may be undetected zones where air change rate is too small, resulting in localized pollutant concentrations. Describes a multi-point tracer gas technique used to quantify air change ratein different zones of various residential buildings. Defines and calculates zonal ventilation efficiency terms, and proposes a criterion for analysis of the results for indoor air quality evaluation.

Treats laboratory and field investigations indicating the danger to health of non-smokers of inhaling tobacco smoke (passive smoking),to the extent that measures to protect the passive smoker are recommended at 1.5 ppm of carbon monoxide concentration caused by smoking and deemed necessary from 2 ppm. Calculations show that in a state of equilibrium a fresh air supply of 33 m3 per hour and per cigarette smoked is needed to maintain the upper limit of 2 ppm carbon monoxide concentration caused by tobacco smoke.

States that a comprehensive sealing program should be considered in every residential energy conservation program. Covers the theory of air flow in a structure , how this theory is converted into a practical service, and theeffect on the house including humidity and air quality concerns. Describes the infiltrometer, a pressurization device used to detect air leakage, how to useit and how to interpret data.

Reports on conference arranged by AIC where main topic was different building standards in different countries. Discusses condensation problems in UK housing and frequency of toxic gases in Scandinavian housing. Notes research into more efficient ventilation and future expectations.

Completed studies indicate that emissions from indoor sources, including those from unvented gas appliances, do not cause any undesirable effects in buildings with normal ventilation rates. However, recent energy conservation measures aimed at reducing ventilation rates have increased the problem of indoor pollutant levels, and there is a need for new, more detailed data on the indoor environment. Describes a programme initiated by GRI to collect such data and to develop control techniques for indoor pollutants.