Variable Refrigerant Volume(VRV) air-conditioning system is more liable to meet thermal environment problem than other systems such as split-type air-or window-type air-conditioner because its capacity of outdoor unit is much higher. When used in high-rise building, hot air dissipated by the outdoor units will induce buoyant airflow and increase the working temperature of units at high floor when these heat can not be dispersed in time. High working temperature could not only degrade the total efficiency, but also cause stoppage of the system.

Pressure coefficients (CP) are fundamental to calculate ventilation rates in buildings by the airflow network models (AFN). This paper deals with the use of CFD simulation to calculate Cp, and the use of those Cp values as input in building energy simulations (BES). The commercial package CFX was used to calculate CP for a 5-stories isolated building, typically found in social housing complexes in Brazil, The standard k-ε turbulence model was adopted.

In this study, the characteristics of the movement of chemical compounds in the concealed spaces and indoor spaces in houses were investigated using building cut models and a simulation program Fresh2006. The equivalent leakage areas in the concealed spaces were measured using cut models of wooden structures: a common wooden structure, an improved wooden structure and a wooden (2 inch x 4 inch) stud structure.

An existing computer model for dynamic hygrothermal analysis of buildings has been extended with a multizone airflow model based on loop equations to account for the coupled thermal and airflow in natural and hybrid ventilated buildings. In water distribution network and related fields loop equations have been widely used to resolve the flow of water and other fluids. In the field of natural ventilation the loop equation method have rarely been used in spite of its quality.

A full-scale test room is used to investigate experimentally and numerically the velocity and temperature fields in the case of a mechanical ventilation. Detailed fields are measured for three cases of ventilation air temperature: an isothermal case, a hot case and a cold case. The experimental data are used to test two turbulence models: a first order k-ε turbulence model and a second order RSM turbulence model. The RSM model predicts the temperature and velocity fields better than the k-ε turbulence model.

house is a dominant factor for animal welfare. There are threshold values or recommendations for the most important climate parameters. Temperature, humidity, CO2 and NH3 gas concentrations, germs, dust, odour and air flow velocity have to be observed. Unfortunately the necessary ventilation of livestock buildings leads to emissions, too. So an important aim is to develop ventilation systems that produce: 

Traffic–related pollutant has been recognized as an air pollution hot spot due to its large emission rate and great health impacts for the exposed population. In the present investigation, a computational fluid dynamics technique is used to evaluate the effect of traffic pollutions on indoor air quality of a naturally ventilated building. The transport of street-level nonreactive pollutants emitted from motor vehicles into the indoor environment is simulated using the RNG k-ε model of the turbulent flows and the pollutant transport equations.

The aim of the present study was to determine the applicability of a genetic algorithm for the optimization of daylighting systems, as well as the requirements for the lighting simulations to be used. Furthermore, by testing the daylighting performance of a building's facade when several parameters are allowed to change simultaneously, the results were used as a complement of previous parametric studies. The goal of the optimization was to maximize energy savings by reducing visual discomfort while maintaining good daylight penetration.

An extended top of the roof can induce the upflowing wind which flows close to the wall and in this way it increases the intake airflow rate in the air gap. A model was set up to save energy with the consideration of a suitable thickness of the air gap and a suitable length of the extended top. The Computational Fluid Dynamics (CFD) was employed to simulate the wind field in the ventilated roofs with extended top and the cases were carried out according to Changsha’s climate parameters in China. The results show that the extended ventilated roof works very well in summer.

Quantification of natural ventilation rates is an important issue in HVAC system design. Natural ventilation in buildings depends on many parameters whose uncertainty varies significantly, and hence the results from a standard deterministic simulation approach could be unreliable.