The flow rate in thermal plumes are influenced by many factors. Influence by enclosing walls is one of them. This article presents simple symmetry considerations to calculate the flow rate in such flows, and they are experimentally verified as regards wall plumes. When the flow takes place near to enclosing walls the entrainment is influenced and a reduction of the flow rate is observed. For displacement ventilation this means a reduction of the stipulated necessary ventilating air flow rate when an air quality based design method is used.

Inter-zone convection affects the general movements of air in a building and must be evaluated for accurate thermal zones heat and mass balance. The paper presents results of an experimental study of convective heat transfers caused by temperature difference between two zones connected by an opening of height 2. 05 m and varying width. Experiments were carried out in a full scale calorimetric chamber (5.5 m x 2.5 m x 2.5 m). Temperature differences were maintained by two active vertical walls locatedon either side of the doorway.

As part of the AIVC's technical programme, study has been performed on present and advanced ventilation systems. The first part of the study presents a review on demands for basic ventilation of residences and major design considerations forventilation systems. The second part is a review on ventilation systems advanced approaches divided into: air movement control systems; flow quantity control systems; ventilation heat recovery systems; alternative ventilation energy systems.Furthermore a system for the classification of ventilation systems is suggested.

Mechanical systems which use common ducts for combined heating and ventilating functions are becoming popular in the Pacific Northwest (U.S.). These systems range from simple fresh-air inlets ducted to the return side of a forced air heating s stem to more complex heat recovery ventilation systems utilizing the K eating ducts for air distribution. Typical integrated systems do not have heat recovery capability.

Reverberant sound excitation and the sound intensity technique have been used for the measurement of the sound transmission loss of narrow slits in rigid walls. A series of experiments was conducted to determine the transmission loss of slit shaped apertures. The measured transmission loss was in good agreement with existing approximate theories over their accepted ranges of validity. However, the effect of viscosity in small apertures was found to be significant and to vary systematically with the dimensions of the apertures.