English

In this paper several kinds of window shading are introduced and compared. In addition, the potential of energy efficiency of exterior shading and three representative windows in three typical cities of China are analyzed and compared using eQUEST software. The objective of this paper is to analyze the influence of window shading in different climate zones of China through simulation. The result shows that in freezing climate zone it is appropriate to use the low-e windows with small U-value.

Failures can lead to a series of problems in the complex heating, ventilation and air-conditioning (HVAC) systems in buildings. Fault detection and diagnosis (FDD) is an important technology to solve these problems. Models can represent the behaviors of the HVAC systems, and FDD can be realized with models. Using the model as intermediary, a link between system simulation and FDD can be built. Simulation has provided a convenient platform of operation for FDD, the overall simulation methodology in FDD of HVAC systems is briefly introduced.

It is difficult to model those complicated objects around buildings, which will obviously affect the flow patterns and temperatures of the outdoor environment. In this paper new method is concluded to solve this kind of modeling problems. Those centralized objects are treated as porous media which will also affect the air flow and turbulence. New source terms are coded into the model to simulate the characteristics. In this way, we can easily model as many as influential factors into the simulation and save much computational time and get a satisfactory result.

In some emergencies, such as fire or accidental release of chemical/biological agents in buildings, it is very useful to simulate the flow on real time or even faster than real time so that proper measures can be taken to minimize casualties. The traditional computational fluid dynamics (CFD) simulation of fire or transient contaminant transport in buildings is accurate but too time consuming, such as by using unsteady Reynolds averaged Navier-Stokes equations (URANS) and large eddy simulation (LES).

In order to make sustainable single houses, it is very important to control the outdoor thermal environment. Therefore, various relaxation methods for the outdoor thermal environment are often planned, e.g. utilizing of the cooling effect of a water face, arrangement of water permeable material, planting trees etc. In this paper, a coupled simulation of CFD and radiation transfer is conducted in order to evaluate the outdoor thermal environment in riverside detached single houses near to Tokyo in Japan.

Air age is an important parameter to assess indoor air quality in ventilated rooms. In order to consider the contribution of ductwork and recirculation, the concept of total air age was proposed for ventilation systems with ductwork and recirculation in previous study. In this paper, about 16 typical cases are simulated with computational fluid dynamics after introducing the method to calculate total air age for ventilation systems with only one AHU and one room in which several inlets and outlets exist.

With the rapid development of computers and CFD, pedestrian level wind study using CFD has become important in engineering design in recent years. In the United Kingdom, wind study is now a common engineering practice and a mandatory documentation for plan authority. The paper presents preliminary CFD simulation of pedestrian wind environment around buildings of typical configuration, size and orientation. The results were compared for flow pattern and the wind velocity amplification value at the pedestrian level, a horizontal surface 1.5 m above ground.

Scientific studies have linked particulate matter with a series of significant health problems. In ventilation systems, indoor particle concentration and dust load on air duct surfaces are two concerns for human health. PROBE-PM (Predicting code for building environment-particulate matter transport simulation), a code to simulate the particle transport in the whole ventilation system is developed.

A new concept, the spatial flow influence factor (SFIF), put forward by us in our previous paper, provides a new insight into the airflow structure. In this paper, several typical illustrative examples are presented to show: (1) how to optimally arrange the chemical pollutant sources and the occupied regions for a given indoor airflow; (2) how to optimize the position of adsorption materials. From the examples,  it is seen that the concept is powerful in the control of indoor air gas pollutants.

Here a generalized 3-D radiation simulation system is developed with Monte-Carlo and Gebhart method. There are two kinds of basic units in the system, which are surface unit for opaque objects and body unit for transparent objects respectively. When the bundles were emitted from certain point or surface with Monte-Carlo method, it would enter into an opaque surface or a transparent body. For the former, it would be reflected and absorbed. However, when the second situation happened, there is the third process named penetration beside above two processes.