Induced-pressure measurements were made in the tower of an eleven-story office building usiInduced-pressure measurements were made in the tower of an eleven-story office building using a fan. The fan was used to depressurize the entire tower as well as a single floor. Sulphur hexafluoride (SF6) tracer gas was used totrace air movements from floor to floor during single-floor depressurization. Average flow coefficients for the tower and for the single floor were estimated from single point measurements. The effect of opening and closing office doors also was determined.
The relationship between the observed concentration of air pollutants at points within a building and the characteristics of the ventilation system is examined, and a basic set of analytical expressions showing these relationships is presented. The extension to large and complex systems is considered, and an example of the application of the equations to an actual air quality problem is given.
A multiple tracer gas method for following air movement in buildings has been developed and demonstrated at the Polytechnic of Central London. This paper describes the method and shows how it is being used to investigate: 1. the whole house inf
Outlines the principles of air flow in buildings: the driving forces of wind and thermal pressure; laminar and turbulent flow; and the effects of the building geometry. Reviews the existing mathematical models of air flow and provides worked examples for a house and a multi-storey building.
States that with improved thermal insulation, ventilation heat losses are becoming increasingly important for the total heat demand of a building, particularly multistorey buildings. Explains how the ventilation heat loss of individual rooms
This study deals with natural heat transfer through apertures between two adjacent rooms. A one-dimensional model has been developed to determine the flow rate and enthalpy rate transferred through each aperture as well as the vertical temperature profile in each room. Results show that flow rate and enthalpy rate vary quasilinearly through time. Temperature profiles show a high thermal stratification depending on the relative location of the apertures. Experiments have been performed in a test apparatus using water. Temperatures have been measured.
Discomfort due to stuffiness and adverse temperature gradients may occur in well insulated rooms with low levels of natural ventilation. Using methods previously applied to studies of convection in the atmosphere, a model of the room air movement
Displacement flow has been found to be the best flow principle for ventilation, with ventilating air being supplied to the occupied zone. The design procedure should, amongst other things, contain an analysis of contaminant source in order to design the ventilating system to create the most favourable flow pattern for the contaminants. This paper deals with design principles and problems related to displacement ventilating systems.
Much research work has been carried out on modelling ventilation air currents. The authors propose that the currents be divided into specific zones, the air parameters of each zone being determined by different conditions. The formula is then derived by the addition of an infinite number of elementary currents flowing from a multitude of point sources. From this, a general formula is proposed to calculate the velocity, temperature and admixture concentration along the whole flow of the current.
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