Perception of Wind in Open Spaces

Abstract

Dense urbanization influences the livability of cities. Changes in local meteorological conditions can be adverse for human health and well-being. In urban open spaces, it is widely known that changes in building density and configuration in cities influence wind speed (V a ). This influence modifies latent heat flux between the human body and surrounding environment and thereby affecting the thermal comfort conditions in open spaces between buildings. Several studies have demonstrated the significant effect of wind speed on outdoor thermal comfort. Melbourne's Central Business District (CBD) has recently experienced dense urbanization and this pattern of development has instigated noticeable changes in meteorological conditions. Some evidence has suggested that the patterns of wind flow induce thermal discomfort during cool seasons. Conversely, the wind is most welcomed during warm seasons. This study was conducted to assess outdoor users' responses to V a in three open spaces of an educational precinct in Melbourne's CBD. The open spaces studied are different in terms of design and function. Users' responses and meteorological conditions were examined through a series of field measurements and questionnaire surveys from November 2014 to May 2015. This study used three perceptual scales to analyze participants' experience of V a during field surveys: "Bedford preference", "thermal sensation" and "personal acceptability". Analytical results yielded the wind perceptual comfort thresholds for different seasons as well as the entire study period. The results suggested that in addition to the geometry of the urban open space, the function of place could influence people's perceptions of V a . The research findings contribute to developing thermally comfortable outdoor environments.Climate 2019, 7, 106 2 of 17 the factors that significantly influence people's thermal comfort, wind speed (V a ) was found to play a key role in cities and particularly in densely built-up areas and between buildings [5,6].Research on wind comfort perception is underpinned by four major methods: software simulations, field tests, wind tunnel tests and questionnaire survey [6]. Questionnaire survey on people's feeling about wind speed is believed to provide accurate, comprehensive and cost-effective method. Since this method evaluates the impact of four parameters (T a , RH, V a, and T mrt ) it is possible to gain an insight into the impact of V a in comparison with the other three parameters. Several studies have demonstrated the significant effect of V a on outdoor thermal comfort [7][8][9]. For instance, the study by Walton, Dravitzki and Donn [7] revealed that gustiness and V a were the most significant factors in shaping outdoor thermal satisfaction. The results of a questionnaire survey in Hong Kong [9] showed that participants were highly sensitive to V a fluctuations. In urban open spaces, it is widely known that recent drastic changes in the design of building density and configuration in cities influence V a profile [5,[10][11][1...

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