Describes a pilot study conducted to test whether increased levels of indoor air pollutants in schools are linked to a swelling in the nasal mucosa. Fifteen subjects were studied at a school with low air exchange rate, and twelve at a school with high air exchange rate. States that absolute values of the minimal cross-sectional area were lower in the school with poor ventilation.
An investigation was performed on the indoor and outdoor air quality of fourteen public places in Hong Kong with mechanical ventilation. They included restaurants, libraries, recreation places, shopping malls, sports centres and a car park. Pollutant concentrations were measured during peak traffic hours at each sampling location. States that the results showed that the indoor/outdoor ratios at public places were higher than those at home and offices.
A model-based technique is described to raise the level of sophistication of building automation systems (BAS). Models are derived using stochastic multivariable identification, and describe the behaviour of air temperature and relative humidity in a full-scale office zone equipped with a dedicated heating, ventilating and air conditioning plant. The models give good accuracy. Investigates the usefulness of the models for facilities management. The 'temperature' model demonstrated substantial improvement of temperature regulation and reduction of energy consumption.
'Fan in wall' is a new ventilation system under investigation for hot and humid climate to assist natural ventilation. Temperature, relative humidity, air velocity, and thermal radiation affect thermal comfort of a person in hot climate. Installation of an air conditioner reduces air temperature and relative humidity to reach a certain level of thermal comfort. Under favourable conditions, increasing air velocity at unchanged temperature and humidity can result in the same perception of thermal comfort.
An experimental study of the thermal performance of an air flow window with triple glazing is described. The measurements were carried out in a climatic chamber under conditions close to a winter season. In the experiments, the temperature and heat-flux distributions on each pane surface, and also the air temperature distribution over the window height at the middle of the ventilated cavity were determined. The thermal performances of forced and naturally ventilated windows with internal cavities of various thicknesses are reported for a wide range of air flow rates.
A hybrid cooling system using radiational panel cooling with wind-induced cross ventilation in an office setting is investigated. The characteristics of the indoor environment are examined using CFD (computational fluid dynamics) simulation, which is coupled with radiation heat transfer simulation and with HVAC control in which the PMV value for the human model in the centre of the room is controlled to be at the set-point (target) value. The system is devised on an energy saving strategy that utilises stratified room air with a vertical temperature gradient.
The context of this work is the development of tools of thermal design adopted in the act of architectural design process, and the difficulty of architects and designers find when using these tools in the analysis of thermal performance of buildings, since this analysis requires specific knowledge. This paper aims to present a simplified method to be used in the preliminary phases of the architectural project process. This method obeys to expert rules which take into account an approach of thermal performance criteria.
Natural and hybrid ventilation concepts are today the mean items of some international researchers about the behaviour in the innovative buildings. In fact they are utilised to contribute to the thermal comfort and the indoor air quality control. Besides there are other advantages as the low use of the energy and the reduction of noise levels. In the last years the study of the hybrid ventilation systems in the office and in the school buildings has in progress as the principal aim of Annex 35, organised by IEA. The present work wants to value the fluid dynamic phenomena organised by IEA.
Airflow pattern in an indoor sports hall of 17,325 m3 located in the sports complex of City University of Hong Kong has been investigated by computational fluid dynamics technique. The turbulence flow was taken into account by using Renormalisation Group method (RNG) k-e model. The objectives of this study are to obtain a preliminary understanding of the airflow pattern and evaluate the badminton 'playing zone' within which there should be no disturbance to the badminton shuttle behaviour.
A mathematical model has been set up for the multizone structure region in this paper. By the way of numerical simulation, the analyses are conducted of air flow and aerosol particle travel under the mechanised ventilation condition. The results of such analyses provide useful data for ventilation system design and the indoor air quality control.