Thermal comfort in ventilated spaces depends mainly on air temperature, air speed and turbulence intensity. Mean air speed is commonly measured with omnidirectional hot sphere sensors, whereas directionally sensitive measurement instruments and CFD-simulations normally give the mean velocity vector. The magnitude of the mean velocity vector in turbulent room air flows can be much lower than the mean air speed due to different time averaging processes. This paper studies the difference both experimentally and theoretically as a function of turbulence intensity.

This work deals with experimental investigations on human reaction to local air movements of people in global thermal comfort, performing light activity. An analysis on draught risk was developed comparing the results with previous research findings on human response to draught. The intensity of air velocity, in terms of mean value and relative turbulence, was referred to the level at which normally clothed people could perceive and feel air movements behind the neck, in global neutral thermal condition.

Air movement can provide desirable cooling in "warm" conditions, but it can also cause discomfort. This study focuses on the effects of turbulent air movements on human thermal sensations through investigating the preferred air velocity within the temperature range of 26°C and 30.5°C at two relative humidity levels of 35% and 65%. Subjects in an environmental chamber were allowed to adjust air movement as they liked while answering a series of questions about their thermal comfort and draft sensation.

Because of the lack of valid information regarding the influence of bends on the thermal and hydraulic performance of flues, a series of preliminary experiments were conducted using a full-scale Perspex rig. Analysis of the results and observations enabled the development of a methodology capable of determining the reduction of flow rate arising from the presence of bends. The analysis has also shown that existing quasi-steady-state methods used for the design of these flue systems are valid.

A literature search was undertaken to assemble and interpretthe-best available· data that can be used for perfonning multizone airflow modelling in mid and high rise apartment buildings. The best currently available data is presented and areas where further field testing research is required are identified. A multizone airflow modelling software tool was used to provide an analysis of ventilation related energy issues in a newly constructed 10 story high-rise apartment building.

Pressure testing techniques have long been used in the laboratory on building components such as windows, for example, to ensure that rain will not penetrate them under windy conditions.

The effects on pressure loss of the separation and orientation of closely coupled duct fittings in RVAC systems were investigated using computational fluid dynamics to analyse the pressure distribution in a system containing two 90° bends in two common configurations; an S bend and a U bend. Fittings that are separated by less than 8 to 10 hydraulic diameters· of the duce behaved in very different ways depending upon the orientation of the fittings in relation to one another.

Researches into natural ventilation characteristics of courtyard buildings have been carried out extensively in climates very different from tropical climate. Nevertheless, courtyards have been incorporated for centuries in traditional shop houses and also adopted in many modern commercial buildings in tropical countries such as Singapore. This paper discuses a study to investigate the natural ventilation characteristics of courtyard buildings in Singapore. Four typical courtyard buildings are examined.