modelling

Natural ventilation coefficient curves were generated using the NatVent 2.0 software, for naturally ventilated livestock building models with a total of 60 design variations including 5 building lengths, 2 sidewall opening heights, 3 ridge opening types, and the presence or absence of end wall openings. An average natural ventilation coefficient curve versus wind angle is also presented. As well, a general design natural ventilation coefficient has been developed and could be used without introducing major errors.

Measurements of interzone airflow and movement of aerosol particles were carried out in an environmental chamber. SF tracer gas and oil-smoke particles were used for this work. A series of measurements were conducted to investigate the effect of parameters such as interzone temperature difference and size of opening on the flow of aerosol particles. The particle deposition rate on thesurfaces of the chamber together with algorithms for interzonal particle flow through the openings were determined. Results were compared with those obtained using the tracer-gas.

This paper is concerned with measurement of air and aerosol particle exchange efficiency in a single zone chamber. Aerosol particles and tracer gases were injected into the chamber and their concentrations were monitored as a funtion of time. The chamber was provided with supply and exhaust terminals which allowed various airflow and particle patterns (e.g. piston flow, displacement flow) to be investigated. The effect of airflow pattern on deposition rate of aerosol particles on the surfaces of the chamber was determined.

This paper presents a trial of applying a CFD package into an air movement study in an old English church. The possibility of adopting computational modelling in a complex shaped building has highlighted the problem encountered due to the large difference in scale between thermal elements and building enclosure. The results have demonstrated that there are still significant problems to be overcome in using CFD models in such situations.

As a result of the "Sick Building Syndrome" (SBS) the confidence of operators of office buildings into HVAC technologies has suffered a considerable drop. One of the most urgent questions before reconstructing or renovating old office buildings is, therefore, whether the air conditioning system to be installed will lead to increasing complaints on behalf of the occupants and how to prevent them. As for indoor air flows, one possibility is given by full scale model experiments leading to results which are very much like the future effective values.