Environmental Design of Buildings

The proposed outdoor classroom is near a highway, resulting in significant noise pollution. Therefore, the primary focus of this design is to prioritize achieving acoustic comfort. Furthermore, visual, and thermal comforts are interconnected in this design, as meeting the visual comfort requirements through sunlight illumination directly affects solar heat gain, consequently impacting the temperature within the occupied space. These climate analyses indicate that increasing the temperature is necessary to achieve thermal comfort during winter months, but it can lead to discomfort during midday in the summer. Consequently, the design should aim to maximize solar heat gain in winter while minimizing it in summer. The main design strategies are based on the sun and wind study using the Brown and DeKay method (Figure 1) and the Bio-climatic chart (Figure 2). The sun and wind study, along with the bio-climatic chart, concluded that the design should obstruct cold breezes from the northeast and allow maximum sunlight in winter while facilitating the entry of Northwestern winds during summer to enhance thermal comfort.

Southern winds must be consistently blocked throughout the year to prevent the infiltration of pollutants from the motorway. Figure 3 elucidates all the implemented design strategies. The most favorable outcomes were observed when the canopy roof consisted of louvers that can be opened to direct wind into the occupied space during summer and closed during winter. Water-filled prismic glass was chosen for the louvers due to its superior daylight transmission properties (higher G-value) and its ability to facilitate higher solar heat gain based on Monte Carlo simulations (Cai and Guo, 2019). The roof profile was specifically designed to mitigate the high levels of noise emanating from the highway.

These louvers are positioned in two directions, enabling the redirection of secondary low-speed winds into the occupied space while obstructing primary high-speed winds. The design proposed additional dense vegetation to be placed northeast of the classroom to impede high-speed winds. The results of this design were evaluated based on the wind blow-up ratio graph by Woodruff and Zing, as well as the sound attenuation by barriers graph by Parkin et al. The wind blow-up graph demonstrated that vegetation reduced high-speed winds from the northeast by 90%, reducing winds with a speed of 2.9 m/s to 0.9 m/s. According to the sound attenuation graph, the roof profile decreased noise levels by 15 dB, reducing noise levels from 65 dB to 50 dB. Consequently, both the acoustic and thermal comfort of students in the outdoor classroom improved significantly through the implementation of passive strategies alone.

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