Twenty three papers from the ninth AIVC Conference, titles as follows: Keynote speech: Air Infiltration and Ventilation; Natural airflows between roof, subfloor and living spaces; Experimental analysis of air diffusion in large space; Determination of ventilation efficiency based upon short term tests; Ventilation strategies in the case of polluted outdoor air situations; Ventilation generated by a fluctuating pressure differential; Air motion in the vicinity of air-supply devices· for displacement ventilation; integral mass mass balances and pulse injection tracer-techniques; Commercial bu

Five supplementary papers from the sixth AIVC Conference as follows: The performance of ventilation in an untight house; Influence of open windows on the interzone air movement within a semi-detached dwelling; Interpretation and error analysis of multi-tracer gas measurements to determine air movement in a house; Inhabitant's behaviour with regard to ventilation. A report of the work of Annex VIII; A multi-tracer system for measuring ventilation rates and ventilation efficiencies in large mechanically-ventilated buildings.