Fountains are delightful sceneries and can provide refreshing surrounding atmosphere, because of the cooling and humidifying effect of water droplets. To create more pleasant environment, it is valuable to quantify the thermal effect of fountains. This paper introduces a numerical fountain model based on particle-source-in-cell (PSI-Cell) model coupling the jet breakup process, the heat, mass and momentum transfer between droplets and air, and the CFD model of airflow, in which the influence of fountain is taken as source terms. A field measurement was conducted, where the data of one hour was selected to validate the fountain model. The presented model is proved to have good precision in the comparisons against the measured temperature and humidity. This new model is capable of estimating the trajectories of droplets, as well as the impact of fountains on the wind velocity, temperature and humidity in the ambient area. Both the numerical and experimental results show that the fountain can improve the thermal environment in the leeward area by strong cooling and humidifying effect, while minor changes have been made in the windward and lateral areas.

Natural ventilation is regarded as one of the most energy-efficient ways of ventilating a building. Suitable methods for predicting ventilation performance are essential for regulating indoor air parameters in buildings. This study establishes a method to predict the natural ventilation potential for residential buildings. The average annual ventilation rate (N) and annual cooling load saving ratio (ACSR) for the top six types of residential buildings were measured and analyzed under different conditions. The N calculation formula was summarized to calculate the natural ventilation air change rate for each of the designated buildings. In addition, the logarithmic regression curves of the ACSR (with N) were also obtained and then used to predict the natural ventilation potential for specific climatic conditions. The simulation results could be used to guide engineers in deciding when and where natural ventilation can be incorporated as an energy-efficient feature without affecting indoor comfort. Moreover, accurate strategic analysis could also be used to assist architects evaluate the potential of natural ventilation at the architectural pre-design stage.

The outdoor thermal environment is very important to pedestrian’s comfort and safety. Under the fast development of urbanization it is essential to develop a quick assessment method to assist design. The present paper introduces a simplified simulation system consisting of convection, conduction and radiation to predict the outdoor thermal environment. A double mesh system for radiation simulation is used to reduce the amount of calculation and storage, meanwhile a thermal response factor method is introduced to calculate the transient heat conduction process. By taking advantage of the thermal response factor method, two kinds of simplified coupling methods are proposed. To validate the simulation system, a filed measurement was carried out and the simulation results are in compliance with the experiment. The simulation results show that the error caused by simplification is acceptable in most conditions, and a lot of coupling calculation amount could be saved.