As part of the Air Infiltration and Ventilation Centre's Numerical Database development programme, Wind Pressure Coefficient data are being collected from many published sources, much of which will contribute to the Centre's ownPressure Coefficient database. To ensure the compatibility and validity of the various data sets, a preliminary comparison has been carried out of the data in use. The work has concentrated on an analysis of the effects of Cp values, for vertical walls, on calculated wind driven infiltration and ventilation rates.

Air Infiltration in Norwegian buildings has been an unknown parameter. This paper is based on results from measurements in nine different buildings in Norway. The measured parameters have been: infiltration envelope air humidity and temperatures on theinside and outside of the building. The infiltration has been measured continuously with tracer gas using the constant concentration method. In addition air tightness measurements and thermography have been carried out to establish the dimensions and the locations of the major leaks.

IEA Annex 23 has been established in order to attempt to resolve these difficulties in relation to multizone air flow modelling. These models are used to evaluate the air flow between individual rooms or zones as well as the rate of inflow andoutflow of air from buildings. This approach is especially important for evaluating the adequacy of ventilation, predicting pollutant transport and evaluating airborne heat transfer between zones. Such models therefore have vital applications in both energy and air quality related analysis.

The scope of the task 2.2 is to provide an algorithm simulating the behaviour of the inhabitants with respect to the openings of doors and windows. The purpose of this report is to present the status of the work carried out by Scartezzini and his colleagues at the LESO-EPFL in this task on May 15th 1989.

The proposed task addresses the measurement methods using several tracer gases to measure the air flow rates between several zones of a building and between these zones and the outside air. If the building has N zones, there are N(N+1) unknown flowrates, which can be measured simultaneously using N different tracers. In so-called active methods the sampling of the atmospheres of the zones is made an active way, that is using either a mechanical pump or a manually actuated syringe or bag.

Mechanical equipment may influence the airflow between rooms in a number of ways: 1) There is the direct airflow through ducts using supplies and returns. This approach may be just a single pass system where supply air enters and exhaust leave

In order to monitor the use of movable air intake grilles by the inhabitants a measurement system is set up in 9 apartments with anatural ventilation system in a building in Namur. The apartments to be monitored are part of an apartment building in Namur wherein a measurement campaign is going on in theframework of a CEC-DGXVII energy demonstration project. A description of the building is given in annex.

Inhabitants may influence the indoor air quality and air flow patterns within buildings in several ways: a) through windows and doors openings; b) through action on mechanical ventilation systems (fans on and off, dampers closed and open, etc); c) creating extra-flow patterns through their own heat, when moving or using portable fans; d) through their activity, inhabitants are an important (but not the only one) source of pollutants. Some of these influences are of great importance (e.g. a and b) or might be negligible, as c) in some cases.

The objectives were a) to evaluate performance of air flow models in predicting air velocity, temperature and contaminant concentrations; b) to evaluate applicability of models as design tools; c) to produce guidelines for their use. All the work is addressed to a single zone. It includes both numerical simulations and experiments for given configurations.