Development of infiltration and interroom airflow calculation methods, driven by a concern for indoor air quality have led to a computer simulation of interroom contaminant movement. The model, which assumes fully mixed room air, shows that open doorways provide rapid mixing between rooms in buildings using forced air heating. It also confirms that it is most energy efficient to remove the contaminant nearest its source. Detailed modeling of the variations in contaminant concentration within a room is not presently feasible for long term energy analysis simulations.
A computational procedure to predict expected rates of natural ventilation for buildings at the design stage is investigated. This procedure integrates three computational methods, namely one to predict temperature induced pressures, another to compute wind generated pressure distributions around buildings, and the third to analyse the networks of resulting air flows in buildings. Experiments show that these methods are valid. The three methods can be used not only for the prediction of natural ventilation, but also for many other environmental engineering applications, e.g.
In order to obtain means for determining realistic convective heat transfer coefficients, a hierarchy of interacting and interdependent calculation methods have been developed by the authors. Both higher and lower level models have been used to develop and verify an 'intermediate level' computer code, which formed the basis for generating input convective heat transfer data for dynamic building models. The contribution considers the computation of convective heat exchange within three-dimensional, rectangular enclosures when buoyancy effects are significant.
One of the recent major developments to the ESP (Environmental System Performance) building/plant energy simulation package has been the integration of a technique capable of performing dynamic air flow analysis as part of the building thermal analysis, thereby permitting simultaneous dynamic modelling of energy and air flow within the building envelope. This paper briefly describes the model and its data requirements. It compares and discusses differences in zone energy requirements and temperature levels (obtained from ESP) when 1. applying traditional air changes rates and, 2.
This paper describes tracer gas measuring techniques that have been used to characterize ventilation and air infiltration in buildings, with an emphasis on recent developments and applications in large industrial and commercial structures. Fundamentals and applications are presented for both single andmultiple tracer gas methods. In addition to techniques suitable for detailed characterization of building airflows, procedures and equipment appropriate to surveying large numbers of buildings are also discussed.
Air qulaity measurements along with airflow rate measurements of air conditioning system were conducted in an office building occupied by workers with clerical activities. Contaminamts measured were CO2, SPM (suspended particulate matters) NOx and airborne bacteria. Indoor CO2 and SPM levels were found to be quite high, 1,600 ppm (CO2) and 0.25mg/ m3 (SPM), respectively, at their maximum and exceeded Japanese Standards The cause of the high concentration was found to be air leakage in the outdoor air intake duct. The air leakage rate was estimated applying mass-balance model of CO2.
This paper describes part of a research programme on energy consumption in the Polish building sector. The work, carried out from 1980 to 1985, aimed at developing methods for measuring air flows and their influence on heat consumption in typic
This paper presents a numerical study of instationary three-dimensional flows. Three methods, a semi-implicit one and two explicit ones were compared and tested on typical flow configurations (lid driven cavity, natural convection and mixed convection in a cavity). These methods were then applied to a problem of ventilation in a paint-booth. The semi-implicit method proved to have a higher accuracy. The explicit method of the M.A.C. type turned out to be more advantageous in calculation time.
This paper describes the numerical analysis of room air distribution by the finite element method which can easily deal with any domain, the boundary conditions and so on.
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