English

That paper shows how a top-down precooled natural ventilation can be an effective and energy efficient technique for providing thermal and ventilation comfort in a wide range of modern buildings during high summer or in warm climates, when used properly.For that study, the top-down precooled natural ventilation of an occupied open-plan space is equipped with a high-level vent and a low-level vent . A chiller unit is connected to the high-level vent to provide precooling. A quantitative model has been developed and tested with analogue laboratory experiments. The results are presented.

Virus transmission through the vertical drainage stack is believed to have been one of the causes of SARS transmission in Amoy gardens, a high-rise residential housing estate in Hong Kong.The authors present their findings on the building drainage system, that include a review of the outbreak incident, the observations and site measurements of foul air and water back flow in the drainage system of another vacant site. The field studies with tracer gas measurements, confirmed the hypothesized infection route.

For this paper 40 studies based on the role of ventilation in airborne transmission of infectious agents in the built environment have been reviewed with two specific research questions :- Is there enough evidence to support that the ventilation and airflow pattern are the causes that contribute for the spread of airborne infectious diseases ?- If so , is there good evidence or data to support the specification and quantification of minimum ventilation requirements to minimize the transmission of airborne infectious deseases ?It appears a strong need for a multidisciplinary study that wo

The objectives of that paper were to :Study the sensitivity and reliability of inhaled air temperature, humidity and gas concentration measurement by a breathing thermal manikinDevelop recommendations for use of breathing thermal manikins in practiceSuggest a method for predicting the quality of air as perceived by occupants, based on measurements performed by a breathing thermal manikin.In that aim results available in literature were analyzed first then experiments were carried out to study the performance of the thermal breathing manikin under different practical conditions.

For the investigation of airflow and pollutant distribution in the isolation room of a hospital, objective measurements and CFD modelling based on three ventilation strategies have been carried out. As a result, the low-level extraction technique appears very effective in removing pollutant at the human breathing zone compared to the ceiling level extraction technique, the best ventilation is the one with the supply air grilles delivering a laminar flow of outside air to the occupant with minimal entrainment of the air in the room.

For the evaluation of IAQ in ventilated rooms, local mean age of air is an important index.To model the spatial-temporal mass distribution in an imperfectly mixed forced ventilated installation, a data-based mechanistic approach was used. The model proved efficient to determine the age of air in a ventilated place.

For that study a CFD steady state computational model of a public transport interchange (PTI) in Hong Kong has been used for the investigation and prediction of the typical pollutant emission pattern for buses. The effectiveness of displacement ventilation (DV) scheme often used for PTI, for the removal of pollutants, has been investigated with the numerical simulation. An alternative model is then proposed with a different location of supply and exhausts to improve thermal comfort and IAQ.

The development of a low order model is outlined in this paper, it can be used for control purposes , and for the quantification of ventilation performance in ventilated systems. First, numerical simulations allowed the generation of an informative pollutant transport data . Then a low order transfer function model was built. The obtained results show that first order model can sufficiently describe the dominant mass transfer dynamics in the ventilated air space.

Multizone models have already been developed to predict airflow and pollutant transport between rooms , and zonal models too to calculate airflow and temperature distribution within single rooms.For that study, a zonal model has been placed within a multizone model to take advantage of those two types, the aim is to increase resolution in the prediction of local air flow velocities, temperature and concentration distributions between and within rooms.Theory and methods are presented in that paper.

OA supply rates are often poorly controlled, but accurate measurements of OA flow rates are necessary. This paper describes results of tests of three technologies that perform well and advises on how those technologies should be applied. Conclusions are presented.