A computational sensitivity analysis was conducted to identify the conditions under which residential active soil depressurization (ASD) systems for indoor radon reduction might most likely exacerbate or create back-drafting of natural-draft combustion appliances. Parameters varied included: house size; normalized leakage area; exhaust rate of exhaust appliances other than the ASD system; and the amount of house air exhausted by the ASD system.

A buoyancy-capture principle is firstly revisited as the most important fluid dynamics mechanism in kitchen range hoods. A recent new derivation of the capture efficiency of a kitchen range hood, which eliminates the inconsistencies and inadequacies of existing derivations, shows that the capture efficiency equals the ratio of capture flow rate to total plume flow rate in a confined space. The result is applied here, together with the buoyancy-capture principle, to derive a simple formula for determining capture efficiency.

This project dealt with developing the method of using activated carbon cloth as a sampler for measuring volatile organic compounds (VOC's) in air. Strips of carbon cloth mounted in slide holders were tested as diffusive samplers. These were exposed to known concentrations of standard chemicals in test chambers. The adsorbed chemicals were extracted with sol vents and analyzed. The tests showed that relative humidity has some effect on adsorption, and carbon cloths from different manufacturers showed some variation in their performance.

This report reviews research into the release of volatile organic compounds (VOCs) from paints and coatings from two perspectives: (a) drying and film formation, and (b) voc emission into indoor air. The former has been investigated by the paint industry for some decades, especially in relation to understanding drying mechanisms to assist product formulation and development. The latter is of more recent interest and is directed to predicting and controlling the impact of VOC emissions from paints and coatings on indoor air quality.

This materials odour emission project was conducted for the Task Force on Materials Emissions and four industry sponsors. The objectives of the project were to review material odour test methods, conduct comparative tests of various materials by the most applicable methods and to recommend test methods for materials odour emission characterization. The review identified six test methods which were then compared in a program of odour testing of 1 0 materials. Two test methods were quantitative odour intensity methods and four methods used perceived intensity and hedonic scales.

Heating ventilating and air conditioning (HV AC) duct insulation in a county government facility in south Florida USA was removed because of heavy fungal infestation of the building. Samples of these materials were examined by direct microscopy and enrichment culture. Additional insulation samples were desiccated for three weeks over silica drying gel, weighed, then placed over saturated salt in water solutions at known relative humidities. At relative humidities approaching 95%, some insulation samples on an average gained 6% of their dry weight in water.