Simulation study of natural ventilation in Beijing: The influence of room structure on energy saving

As Beijing becomes a modern yet more populated city, people now are faced with an increasing number of choices when they want to purchase commercial building. Beside from apartment price, location and other factors, building room structure has always been a major determinant for apartment buyers. Traditionally, when it comes to the room structure people will mainly focus on space-sufficiency as well as convenience. This paper tries to explore the importance of the building room structure in terms of energy saving and energy saving ratio. The differences of various types of building structures are mainly about space allocation of different rooms and directions each window or door is facing. Such difference will lead to the variation of the level of natural ventilation. Besides, natural ventilation is the most common way to provide fresh air to indoor environment. To study the difference of natural ventilation for different room structures, this paper focuses on three most common room structures with the same building outer design. The changes will only be made on the location of different rooms in a household and the orientation of each room's door, window etc. By using CFD simulation software, the first simulation will be about the external wind field of the building and to get the tuyere air pressure. Then DeST-VENT+, a software developed by Tsinghua University specified for building environment design simulation, is used to calculate the cooling and heating load for the building. After that a thorough comparison between different room structures and building load is made. Finally, we can find that the influences room structure has on building energy saving ratio cannot be ignored and ventilation demand and ventilating ability are two main factors when we analyse energy-saving ratio.