Predicting and understanding temporal 3D exterior surface temperature distribution in an ideal courtyard

Micro-scale heat island phenomenon refers to the temperature rise of a micro-scale built area, e.g. a street, a square and/or even an urban district above the ambient air over the area. This paper presents a simple temporal 3D air and surface temperature model for an ideal courtyard, which is a semi-enclosed open space surrounded by buildings. The prediction model includes the transient heat conduction in the ground and through the buildings walls, the heat removal/addition by courtyard ventilation, and detailed solar radiation and thermal radiation exchanges between surfaces. The air temperature in the courtyard and its surface temperature distribution can be analyzed minute by minute within a day or during a longer period if the temporal ambient air temperature and weather data are given. We simulated a courtyard located in Beijing. The solar radiation and the urban structures are found to be the most important factors in determining the courtyard thermal environment during both summer and winter. The thermal properties of the building walls also play a significant role. The results are revealing in developing effective methods for mitigating or managing micro heat island, and control thermal environment in a courtyard.

► A 3D air and surface temperature model of an ideal courtyard model was developed.
► The model includes almost all the possible thermal exchange processes.
► Larger thermal mass and conductivity delay the peak temperature at day time.
► The height of the courtyard is the most influencing factor on its thermal environment.