Comfortable wind velocity ranges in

Comfortable wind velocity ranges, in function of the activity exercised outdoors, have been defined by the American Society of Civil Engineers (ASCE)—based on 20% probability of exceedance. Table 1 depicts the wind velocity values—that signify both mean wind velocity and gust equivalent mean velocity (UGEM). The UGEM is the ratio of the peak 3s-long gust exceeded about once every 5 to 10min and the representative fixed gust factor, G, typically taken as about 1.85 (ASCE, 2003). Other authors refer to similar threshold values: Gandemer and Guyot established a maximum average wind velocity of 5m/s as a general outdoor comfort limit, with a turbulence intensity of 0.2, i.e., 1m/s and proposed an average wind velocity of 3.0m/s with a turbulence intensity of 0.2, i.e., 0.6m/s for long outdoor stay and sedentary or very moderate physical activity, such as following a football match at an open stadium or having at drink at a terrace (Gandemer and Guyot, 1976; CSTB, 2002). Safety criteria are stricter, regarding the probability of exceedance, than wind comfort criteria. The gust speeds that are sufficient to blow people over have been estimated by various authors and are in the range of 15–30m/s, depending on other factors including the size, weight, reaction time, health and clothing of the person (ASCE, 2003). If these wind thresholds are exceeded two or three times a year, the chance of someone being injured becomes unacceptably high. Two or three times per year corresponds to an occurrence of 0.1% of the time (ASCE, 2003). The wind rose for Dublin Airport indicates that high wind velocities (exceeding the 5.4m/s threshold) are frequent from W, WSW, SW, SSW and WNW directions; and they these details occur during about three-quarter of the total time period. Regarding all directions, during daytime (between 9 am and 9 pm) wind exceeds the 5.4m/s wind comfort threshold value during 872h of the year and results in excessive wind, unsuitable for any type of outdoor activity. Table 2 illustrates wind data collected at Dublin Airport for year 2005. It indicates that during more than 80% of the year—altogether 3873h out of 4745—wind conditions are suitable to exercise outdoor activity in Dublin during the day, according to the ASCE criteria.
Study area Dublin is one of the most popular tourist destinations in Europe with visitor numbers exceeding 6.6 million per year. Most of the visitors, almost 50%, come from the UK and a third from Europe Mainland (NTDA, 2010). Visitors welcome outdoor and semi-outdoor locations where they can enjoy cultural and retail facilities. Compared to cities with similar climate characteristics and latitudes, there are few facilities available in Dublin inviting people to spend outdoors for a longer time period. In the past, the focus on establishing indoor comfort has detracted attention from the outdoor climates, which for much of the year in Ireland, is suitable for outdoor activities.
Thermal comfort and its assessment at outdoor locations Human thermal comfort research has received little attention in outdoor locations in Ireland. As mentioned previously, a study on thermal comfort in summer in relation to the adverse effect of rain, carried out by Leech (1985) seems to be sole available source in the field. Thermal comfort indoors has received more focus, since it is regarded as directly related to health and productivity at work. However indoor comfort conditions and building energy consumption are strongly linked with outdoor climatic characteristics and deserve more attention. Citizens spend a considerable amount of time in public urban spaces, so the provision of comfort should be regarded as an environmental health question of paramount importance.
Materials and methods First, the history of Dublin Docklands and the drivers of modern urban planning that have shaped the Dublin Docklands during the last few decades have been apprehended. Then, thermal comfort has been modeled computationally for the background climate, for the chosen reference year 2005, by the thermal comfort and microclimate simulation tool RayMan, using the thermal comfort index PET (Matzarakis et al., 1999; Matzarakis et al., 2007). The PET index has been chosen because it provides information on the global thermal environment taking into account both the environmental parameters and the physiological reaction of the human body.