Browsing by Subject "Outdoor thermal comfort"

Now showing 1 - 4 of 4

Open Access
Assessing the influence of street configurations on human thermal conditions in open balconies in the Mediterranean climate
(Elsevier, 2021-10-04) Rodríguez-Algeciras, J.; Tablada, A.; Nouri, Andre Santos; Matzarakis, A.
Heat stress in the built environment has become a serious health and comfort issue, given the increases in Urban Heat Island effects, and augmenting impacts associated to climate change. This study deals with the potential correlations between human thermal conditions, the encircling microclimate, and the physical structure of the city. Through long-term numerical simulations, the disclosed study analyses the influence of the urban street configurations on the thermal bioclimate within urban canyons, specifically upon open balconies in the most populated district of Barcelona: The Eixample. The simulated thermal conditions were carried out in the human biometeorological RayMan Pro model using local climatic data, to determine the Physiologically Equivalent Temperature (PET) within four generated scenarios, with similar morphological properties of the Eixample district. The findings reveal that streets with axes oriented NS and SE-NW provide the best thermal conditions for balconies, achieving acceptable PET values (18 °C < PET <29 °C) on both façades. On the other hand, EW streets presented high thermal stress conditions (over 43,4% of the time) for those balconies located in the north side of the canyon. Open balconies at heights below 12 metres are the most comfortable ones during summer daytime, with acceptable thermal conditions that range between 50,4% and 82,5% of the time. The highest frequencies of acceptable thermal conditions were found on balconies located at 6 metres and 9 metres high on the east, south and southeast façades of the NS, EW and NE-SW oriented streets respectively (from 77% to 83% of the time). These configurations provide the most suitable thermal conditions during the studied summer periods by having frequencies of heat stress below 20%. Our results and recommendations contribute to bridge the gap between human biometeorology, public health, and architectural and urban planning. Some areas of its direct application are the use of balconies in periods of confinement; decision-making on the sale or rental of apartments; and the promotion of bioclimatic retrofit projects at an urban and architectural scale supported by local governments.
Open Access
Human thermo-physiological comfort assessment in Lisbon by local climate zones on very hot summer days
(Frontiers Research Foundation, 2023-05-17) Reis, C.; Nouri, Andre Santos; Lopes, A.
Extreme heat is a current and future issue on urban areas, with negative impacts on health and quality of life (increasing morbidity and mortality rates). This paper analyses day (12:00–15:00 h) and nighttime (00:00–03:00 h) thermo-physiological comfort (TC) conditions by Local Climate Zones (LCZ) in Lisbon during a particular Local Weather Type (LWT), very hot summer days. For this, 13 different microscale sample areas were chosen covering urban and non-urban land cover classes (LCZs 1–3, 4–6, 8, 9, A and B). Universal Thermal Climate Index (UTCI) and Mean Radiant Temperature (MRT) were modeled on SkyHelios software for 163 days between 2008 and 2014. Results show that during the day all urban LCZ samples depict the same average TC conditions (average UTCI of 34°C—strong heat stress) and densely wooded areas are 2°C cooler (average UTCI of 32°C—moderate heat stress). However, compact areas (LCZs 1–3) with low sky view factor and some vegetation (street trees) display lower percentages of area with higher thermo-physiological discomfort (TD) levels (83% with strong heat stress against 98% in LCZs 8 and 9 and 100% in LCZs 4–6). When considering the hottest days (air temperatures equal or above 35°C—75th percentile), the moderate heat stress class disappears in all samples and the very strong heat stress class appears only on urban areas, occupying between 12% and 16% on LCZs 1–3, 10%–22% on LCZs 4–6, 16%–22% on LCZs 8 and 9 on LCZ 9. During the nighttime period all samples show no thermal stress, favoring nocturnal physiological recovery. TC conditions in Lisbon are strongly influenced by solar radiation and wind, which explains the need to increase the shading area, preferably by trees, and to promote and preserve ventilation paths.
Open Access
Investigation of the relationship between human thermal comfort and activity patterns within the outdoor spaces of Bilkent University’s Main Campus
(2023-06) Seyednouri, Hadi
The impact of climate change, resulting in rising temperatures, is believed to significantly influence the success or failure of outdoor spaces, with climatic factors playing a crucial role. Research has indicated that the maintenance of a comfortable thermal environment can have a notable impact on individuals' welfare. To date, global climate studies have not provided sufficient local specificity for urban planning and design. Consequently, there has been an increasing interest in incorporating complementary bottom-up perspectives. In line with this interest and focused on a particular case study, this thesis presents the findings of an empirical investigation conducted between May and September of 2022 at the main campus of Bilkent University located in Ankara, Turkey. In order to address physiological and psychological aspects of human thermal comfort and investigate the possible effect of human thermal comfort on lecturers’ and students’ activity patterns within outdoor spaces of the aforementioned campus, a two-phase study was designed. 12 days of observational studies during the first phase of this research produced a behavioral map, which when combined with a Shadow Behavior Simulation (SBS) map established the Points Of Interest (POI) of this research. Subsequently, in the second phase, 64 questionnaires were filled out by the pedestrian while microclimatic factors were measured in the POIs over the course of 13 days. In order to address the stated research questions, test the hypotheses, and propose design recommendations, through the application of the biometeorological RayMan model, the Physiologically Equivalent Temperature (PET) index, and modified PET were applied, along with statistical analyses using the Statistical Package for the Social Sciences (SPSS) and the cognitive maps considering microclimate. The findings of this study demonstrated good agreement between quantitative and qualitative results, presenting solar radiation as the most significant microclimatic factor. Human thermal comfort also had an impact on activity patterns within the study area, but not as significantly as seating availability for stationary activities and planning and function for moving activities.
Open Access
The relationship between preference utilizing VR and synoptic thermal evaluation the case of public square of Amirkabir, Arak
(2022-12) Taghavi Araghi, Seyed Mahziar
Public Open Spaces (POS) have been proven to have a positive effect on people’s life and overall well-being. As also suggested by the existing literature, the success of a POS can be interrelated with the number of individuals using it. However, the occurrence of Urban Heat Island (UHIs) has increased in recent years as a consequence of climate change which can significantly affect the presence of people in POSs and their usage pattern. Urban green spaces on the other hand can provide shade that covers outdoor environments, attenuating the effects of UHIs. In addition, urban inhabitants can benefit from psycho-physiological advantages of urban green spaces. Meanwhile, Amirkabir square as the first environment with the main concentration on pedestrians rather than vehicles in the city of Arak, needs urgent improvements in both aesthetics and thermal condition. To accomplish this aim, alongside thermal sensitive decision making, the use of virtual reality (VR) as a participatory means can offer a unique opportunity to ensure the positive effects of local interventions. This method and the integrative mergence between these two issues, and how they can frame an initial guidance for local design- oriented action, are interlinked contemporary factors that need to be addressed. As a result, the study's primary objective is to provide interdisciplinary recommendations for architects and urban designers on how to effectively approach the alternation of POSs for enhanced greenery design to approach both thermal comfort and psychological expectations. Hence, this study investigated people's preferences in four greenery design scenarios using VR techniques, then compared them to thermal comfort situations to determine whether the preferred scenario chosen by Araki inhabitants is the same scenario in which people performed best or not. People’s preferences were studied using VR technology and SPSS software for data interpretation. The quantitative thermal microclimatic conditions of Amirkabir urban square were obtained through the application and comparison of energy-based model thermal indices. These indices were the Physiologically Equivalent Temperature (PET) and the modified PET (mPET) through the use of biometeorological RayMan pro model. To facilitate the representation of the results, the Climate Tourism/transfer Information Scheme (CTIS) software was utilized. This innovative methodology revealed in the case of Arak, that the scenario preferred by people (Scenario D, p<.05), is different from the scenario with better thermal performance (Scenario A), and that people’s preferences and thermal outcome on different design scenarios are not necessarily parallel, which draws on local design and planning orientated professionals that shape cities to work in an interdisciplinary manner whilst addressing such crucial aspects. Through such a perspective, the modification of the urban fabric can be made to better ensure the long-term triumph of urban projects.