English

The air pumping effect of a fire plume, proposed years ago, to give a higher air intake rate through vertical openings in a compartment fire is further investigated in this paper. Equations for the air intake rate through vertical openings found in the literature are reviewed. As most of the reported correlation expressions were derived empirically from experiments, results might be different if the fire geometry, fuel type and ambient conditions are different.

As compared to mixing ventilation systems, the personalized ventilation system (PV) can help to create a healthy and comfortable working environment with a simultaneous reduction of energy consumption. This latter aspect should be of particular significance for employers and investors who bear responsibility for office space conditions. The parameter which is of paramount interest for this group of people is productivity as it translates into a company’s revenue.

The built environment in China is required to achieve a 50% reduction in carbon emissions by 2020 against the 1980 design standard. A particular challenge is how to maintain acceptable comfort conditions through the hot humid summers and cold desiccating winters of its continental climate regions. Fully air-conditioned sealed envelopes, often fully glazed, are becoming increasingly common in these regions.

With the rapid development of urbanization, the economy and number of vehicles, the urban climate has worsened in recent years, causing serious urban problems including urban heat islands, air pollution and infectious disease transmission. Ventilation is indicated as one of the most effective approaches to solve these problems.

To study the thermal effects on airflow in a street canyon under real heating conditions (due to diurnal solar radiation), a one-way static approach combining an urban canopy model and CFD is proposed in this paper. An urban canopy model was developed to calculate the individual temperatures of surfaces in the street canyon. The calculated surface temperature may be used as a thermal boundary for CFD simulation. The reliability of this model was validated against a field experiment in Harbin, China.

This study presents an optimization method of sensor layout to improve identification accuracy of indoor contaminant sources. The method integrates an index, the performance of sensor layout (PSL), with a two-step screening procedure to determine sensor layouts that have potential to achieve relatively high levels of accuracy in source identification. Using the PSL, the performance of each possible sensor layout can be predicted and evaluated, and therefore the optimization method can be performed without running a source identification model.

This paper focuses on the performance of a new air curtain ventilation system. Particle Image Velocimetry (PIV) is used to visualize and investigate the airflow characteristic of an air curtain in an enclosure and the airflow pattern and temperature fields are measured and analyzed in detail. The air supply velocity and the slot inlet location were varied during the experimental process. The current results show that with the increase of air supply velocity the cooling effect in the occupied zone is further strengthened.

Based on the theoretical and experimental studies of natural ventilation, the performance of natural ventilators has been analysed. Four types of natural window ventilators and three types of wall ventilators were studied. Experimental results show that the natural ventilators have a greater ventilation effect whilst meeting national and local standards of ventilation for residential buildings in heating or cooling seasons.  The installation of such devices can be a compromise between ventilation and energy loss.

In order to get more effective natural ventilation into a room with a single sided opening or large depth, two new window types have been developed in the laboratory. These are based on three new patent developments. The first window is defined as a dual level ‘up-down folio’ window which consists of two pairs of openable sashes with one pair placed directly above the other.  The second is a multi-sash mid-pivoted window with vertical deflectors.

This paper presents a method for predicting occupants’ indoor thermal sensation in naturally-ventilated environments, based on real thermal sensation samples, using a GA-BP neural network model. This method improves the traditional back propagation neural network by incorporating an integrated genetic algorithm into the BP neutral network which aims to optimise the connection weight or threshold of the parameters in the input layer of the GA-BP neutral network model, which represent the factors affecting adaptive thermal comfort.