Describes case studies of two sick Canadian buildings. The first illustrates a comprehensive programme of measuring air quality, ventilation and thermal conditions as well as monitoring the performance of the heating, ventilating and air conditioning systems. The second illustrates use of a standard survey questionnaire with back-up field monitoring of environmental parameters. In the first building the ventilation system was found to be malfunctioning. In the second building the humidity was very low.

States that although controlled mechanical ventilation is becoming more widespread, the installations and their application are capable of improvement. Illustrates diagrammatically and explains methods of improving the components, their installation and operation. Considers ways of improving the air tightness of the buildings. Concludes by describing methods of simulating the performance of controlled mechanical systems, which facilitates the evaluation of measures aimed at improving their operation.

Presents four short articles treating aspects of building ventilation: 1) Achieving a balance - the work of the AIC, 2) House full of horrors - indoor air pollution and progress in eradicating hazards, 3) Letting off steam - test houses with ventilation system for condensation control, and 4) High and dry - condensation in the roof, eaves to eaves ridge ventilation.

Describes construction of two townhouses taking into consideration several technical issues: 1) limiting of indoor sources of contamination, 2) limiting contaminants off-gassed from construction materials, 3) limiting entry of exterior contaminants, 4) control of occupant generated contaminants by mechanical and by natural ventilation, and 5) control of indoor humidity The units are to be monitored over the next two years.

Reviews ways of reducing energy loss due to infiltration while maintaining air quality. Results from existing houses are presented. Describes a method to reduce the average air flow coefficients of the envelope to minimum required values and to determine the heat criteria of various ventilation systems.

Computer programs INFILS and ACFES2/R have been developed for the analysis of industrial buildings' heating loads and energy consumption relating to air infiltration. The heat demand computation results for typical hall structures are presented. It is shown that on windy days with low outside temperatures, total heat losses rose to 180% of basic heat losses. The necessity of developing proper methods for designing, building and testing elements of industrial buildings is emphasized.

The heating of air infiltrating through cracks around doors and windows forms an important part of the heat balance of buildings. The complexity of the problem makes it difficult to calculate. Describes the development of an insitu method for measuring the infiltration of buildings.

This paper reports on measurements of air change rate in dwellings during occupancy. The occupants were shown to exert a considerable influence on the total air change. The air change rate for occupied dwellings is, on average, 3-4 times greater than the air change rate in sealed dwellings (with air escape valves, doors, windows, and ventilation system closed). The measurements also reveal a tendency for higher air change rates in mechanically ventilated dwellings than in naturally ventilated dwellings.

Describes a procedure for determination of the rate of air leakage through a building's exterior envelope resulting from specified air pressure differences. The method, based on Swedish standard SS 021551, can be used tomeasure the whole building leakage or just a specific part of the envelope. The air flow and the pressure differences are recorded for a number of pressure differences, both positive and negative.

The interaction of air leakage and transmission heat through a double frame window makes the overall heat loss less than the sum of them acting separately. Theoretical calculation shows that in the case of infiltration, a double frame window may recover 21% to 32% of air leakage heat loss, and exfiltrated air through a double frame window not only loses no energy but, on the contrary, reduces the energy consumption of heat transmission, covering 23% to 36% of the enthalpy drop of exfiltrated air before and after leakage. Experimental data and field test agreed well with these results.