By means of a case study involving a severe case of coupled heat and sir flow in buildings, this paper aims to quantify the differences resulting from different methods (ping-pong and onion approach) for linking heat and air flow models. The main conclusion is that when used improperly, the onion method will have implications in terms of computing resources, but - more seriously - the ping-pong method may generate substantial errors.

To achieve acceptable indoor air quality (IAQ), ASHRAE Standard 62-1989 recommends the use of the alternative IAQ procedure. The IAQ procedure can treat both constant-volume and variable-air-volume (VAV) with constant or proportional outside airflow rates. The relationships in Appendix E of the standard must be used in conjunction with the IAQ procedure to directly calculate indoor air contaminant concentrations in an occupied space.

A computer program has been developed to predict the wind pressure coefficients Cp on facades and roofs of block shaped buildings. The program is based on fits of measured data, including wind shielding by obstacles and terrain roughness. Main advantages of the program are: - it needs no expertise of its users on wind pressures; - the input is simple. It exists of building and obstacles coordinates and orientations; - generating Cp values for ventilation model calculations needs no separate action.

The ventilation of an attic is critical in estimating heating and cooling loads for buildings because the air temperature in the attic is highly sensitive to ventilation rate. In addition, attic ventilation is an important parameter for determining moisture accumulation in attic spaces that can lead to structural damage and reduced insulation effectiveness. Historically, attic venting has been a common method for controlling attic temperature and moisture, but there have been no calculation techniques available to determine attic ventilation rates.

This paper describes the new indoor environment research facility recently constructed at the Institute for Research in Construction, National Research Council Canada. This facility allows full-scale testing and physical modelling of office space lighting, thermal comfort, indoor air quality, airflow and contaminant-flow patterns, ventilation, acoustical characteristics, and occupants' reactions to these parameters. The facility consists of a test room, approximately, 12 m by 7 m by 2.74 m high, with adjustable interior partitions.

The Dutch E novation program is a national demonstration program in which dwellings with high energy consumption, moisture and mould problems and poor indoor air quality were renovated, with special attention to the selection of the heating and ventilation systems, thermal insulation and the building physical details. A number of indoor air quality parameters were monitored before and after renovation, showing an important improvement in the indoor air quality.

Three different examples illustrate the possibilities offered by the use of tracer gas methods for detailed airborne moisture transport studies in building. The first one concerns an individual dwelling with severe condensation problems, the second one gives an example of statistical data collection of humidity related parameters in 18 apartments and the last one focuses on the evaluation of the amount of water evaporating from the building materials of a recently built low energy dwelling and on the energy consumption required for drying the construction.

In order that sampling points may be strategically located, it is desirable to have knowledge of the spatial variation of ventilation eflectiveness parameters prior to measuring them using tracer gas sampling techniques. The research described in this paper is being carried out to establish a tracer gas sampling strategy as well as to facilitate the prediction of ventilation effectiveness parameters. The procedure developed requires the division of the internal space into a large number of cells and, by the application of CFD, the mass flow rates between adjacent cells to be established.

Thirty-one independent fan pressurization measurement series were performed on seven apartments in three family housing buildings at Fort Riley, Kansas, using four protocols. The tests followed procedures in new or revised fan pressurization standards by the International Standards Organization (ISO), American Society for Testing and Materials (ASTM) and Canadian General Standards Board (CGSB). In addition, the effect of interzonal flow was considered. The three standards gave similar results.

ASHRAE has developed a draft of a measurement standard, Standard 129, entitled "Standard Method of Measuring Air Cliange Effectiveness." This standard defines a method of measurement for measuring air change effectiveness in mechanically ventilated spaces, and provides a discussion of how the values of air change effectiveness may be used to demonstrate compliance with ASHRAE 62-1 989.