The conservation of historical urban centres is an important resource to encourage liveability and sustainable development of cities in the context of global climate change. It is a complex process ...that serves diverse perspectives, among them is the thermal comfort. The paper analyze the contribution of street configuration towards the improvement of thermal comfort at pedestrian level, in the Old Town of Camagüey-Cuba (World Heritage Site, since 2008). Simulations performed are run for summer and winter solstices by using RayMan model. The urban settings are represented by symmetrical street canyons (380 m long, 9 m width), with different solar orientations (i.e. N–S, NE–SW, E–W, NW–SE) and aspect ratios (i.e. H/W = 0.5, 1, 1.5, 2, 3, 4, 5). Results are presented in terms of Physiologically Equivalent Temperature (PET). Our findings confirm that the spatial distribution of thermal conditions at street level, depend strongly on aspect ratio and street orientation. The results show extreme patterns of thermal comfort between N–S and E–W streets. Rotation to N–S orientation is a valid strategy to mitigate the heat stress in summer, with reductions of up to 2 h at the center of the street. Aspect ratios between 1 and 1.5 offer a quite acceptable thermal performance for summer and winter. PET patterns discussed give information about the most suitable locations for pedestrian within the street. The urban guidelines presented enable to urban planners rehabilitate and design cities, which are able to reduce the impact of thermal stress in hot-humid climates. The results could be included in the Urban Regulations of Camagüey.
•Liveability and sustainable development of urban centres in the context of global climate change.•The contribution of street configuration towards the improvement of human thermal comfort conditions.•Support to evaluate temporal-spatial distribution of extreme thermal conditions at pedestrian level.•Suitable spaces, uses of the street, and bioclimatic resources of design into urban canyons.•Urban guidelines to design cities, which are able to reduce the impact of thermal stress.
In order to contribute to the sustainability of the outdoor environment, knowledge about the urban thermal bioclimate should be transferred into climatic guidelines for planning. The general ...framework of this study responds to the need of analyzing thermal bioclimate in Mediterranean climate regions and its influence as an urban design factor. The paper analyzes the background of the urban climate and thermal bioclimate conditions in Barcelona (Spain), through the effect of shade conditions and wind speed variations. Simulations of shade and wind speed variations were performed to evaluate changes in thermal bioclimate due to modifications in urban morphology. Air temperature, relative humidity, wind speed, and solar radiation for the period from January, 2001 to January, 2015 were used to calculate physiologically equivalent temperature (PET) using the RayMan model. The results demonstrate that shade is the most important strategy to improve urban microclimatic conditions. In Barcelona, human thermal comfort conditions can be improved by shade and wind speed increase in terms of PET above 23 °C and by a wind speed decrease for thresholds of PET below 18 °C. Heat stress situations can be mitigated by shade and wind speed increase in conditions above 35 and 45 °C, respectively. The results of the study are an important contribution for urban planners, due to their possibilities and potential for the description of microclimatic conditions in Mediterranean climate regions. The knowledge is useful for improved human thermal comfort conditions, from the suitable configuration of urban form and architecture.
Climate regional characteristics, urban environmental conditions, and outdoors thermal comfort requirements of residents are important for urban planning. Basic studies of urban microclimate can ...provide information and useful resources to predict and improve thermal conditions in hot-humid climatic regions. The paper analyzes the thermal bioclimate and its influence as urban design factor in Cuba, using Physiologically Equivalent Temperature (PET). Simulations of wind speed variations and shade conditions were performed to quantify changes in thermal bioclimate due to possible modifications in urban morphology. Climate data from Havana, Camagüey, and Santiago of Cuba for the period 2001 to 2012 were used to calculate PET with the RayMan model. The results show that changes in meteorological parameters influence the urban microclimate, and consequently modify the thermal conditions in outdoors spaces. Shade is the predominant strategy to improve urban microclimate with more significant benefits in terms of PET higher than 30 °C. For climatic regions such as the analyzed ones, human thermal comfort can be improved by a wind speed modification for thresholds of PET above 30 °C, and by a wind speed decreases in conditions below 26 °C. The improvement of human thermal conditions is crucial for urban sustainability. On this regards, our study is a contribution for urban designers, due to the possibility of taking advantage of results for improving microclimatic conditions based on urban forms. The results may enable urban planners to create spaces that people prefer to visit, and also are usable in the reconfiguration of cities.
The conservation of historical urban centres is an important resource to encourage liveability and sustainable development of cities in the context of global climate change. It is a complex process ...that serves diverse perspectives, among them is the thermal comfort. The paper analyze the contribution of street configuration towards the improvement of thermal comfort at pedestrian level, in the Old Town of Camagueey-Cuba (World Heritage Site, since 2008). Simulations performed are run for summer and winter solstices by using RayMan model. The urban settings are represented by symmetrical street canyons (380 m long, 9 m width), with different solar orientations (i.e. N-S, NE-SW, E-W, NW-SE) and aspect ratios (i.e. H/W = 0.5, 1, 1.5, 2, 3, 4, 5). Results are presented in terms of Physiologically Equivalent Temperature (PET). Our findings confirm that the spatial distribution of thermal conditions at street level, depend strongly on aspect ratio and street orientation. The results show extreme patterns of thermal comfort between N-S and E-W streets. Rotation to N-S orientation is a valid strategy to mitigate the heat stress in summer, with reductions of up to 2 h at the center of the street. Aspect ratios between 1 and 1.5 offer a quite acceptable thermal performance for summer and winter. PET patterns discussed give information about the most suitable locations for pedestrian within the street. The urban guidelines presented enable to urban planners rehabilitate and design cities, which are able to reduce the impact of thermal stress in hot-humid climates. The results could be included in the Urban Regulations of Camagueey.
The incorporation of climate and environmental resources into the sustainable development of contemporary tourism is a challenge that requires special attention. From this imperative approach, the ...trustworthy information on local tourism-related climate and bioclimate conditions is a growing need, and influences the tourists’ travel decision-making process. This study aims to increase the sensitivity towards tourism-related climate information to support an adjusted and responsible planning in the tourism industry in Barcelona, Spain. The assessment of local climate and bioclimate conditions was conducted by using meteorological data from 2007 to 2017. Accordingly, a bioclimatological brochure with practical use was designed integrating thermal, esthetic, and physical climate facets for tourism, which were analyzed in 10-day intervals and combined with the Climate-Tourism-Information-Scheme (CTIS). The CTIS of Barcelona highlights that the most suitable climatic and bioclimatic conditions last from the end of February to the first 10 days of June, and from September to mid-November, where all analyzed parameters converge at a relatively high rate of ideal conditions. This study certainly is a contribution on how to evaluate the climate and bioclimate for a defined destination from the perspective of tourism. The results here provided are crucial for tourism planners, visitors, tourism attendees, and health authorities. Furthermore, they should be used to encourage and establish decisive strategies to mitigate the seasonality of tourism.
Walkability and livability in cities can be enhanced by creating comfortable environments in the streets. The profile of an urban street canyon has a substantial impact on outdoor thermal conditions ...at pedestrian level. This paper deals with the effect of asymmetrical street canyon profiles, common in the historical centre of Camagüey, Cuba, on outdoor thermal comfort. Temporal-spatial analyses are conducted using the Heliodon2 and the RayMan model, which enable the generation of accurate predictions about solar radiation and thermal conditions of urban spaces, respectively. On these models, urban settings are represented by asymmetrical street canyons with five different height-to-width ratios and four street axis orientations (N-S, NE-SW, E-W, SE-NW). Results are evaluated for daytime hours across the street canyon, by means of the physiologically equivalent temperature (PET index) which allows the evaluation of the bioclimatic conditions of outdoor environments. Our findings revealed that high profiles (façades) located on the east-facing side of N-S streets, on the southeast-facing side of NE-SW streets, on the south-facing side of E-W street, and on the southwest-facing side of SE-NW streets, are recommended to reduce the total number of hours under thermal stress. E-W street canyons are the most thermally stressed ones, with extreme PET values around 36 °C. Deviating from this orientation ameliorates the heat stress with reductions of up to 4 h in summer. For all analysed E-W orientations, only about one fifth of the street can be comfortable, especially for high aspect ratios (H/W > 3). Optimal subzones in the street are next to the north side of the E-W street, northwest side of the NE-SW street, and southwest side of the SE-NW street. Besides, when the highest profile is located on the east side of N-S streets, then the subzone next to the east-facing façade is recommendable for pedestrians. The proposed urban guidelines enable urban planners to create and renovate urban spaces which are more efficient in diminishing pedestrian thermal stress.
The combined effect of climate change and Urban Heat Island (UHI) effect is leading to a rise in air temperature in urban areas, including those with heritage value. Urban morphology and its effect ...on sun shading conditions in tropical cities is crucial to reduce UHI and improve outdoor thermal comfort. This paper presents a temporal-spatial analysis of the effect of courtyards geometry on their outdoor thermal conditions in a warm-humid climate. The assessment is based on numerical simulations of the mean radiant temperature, by using the RayMan model. Large courtyards geometry (convent typology), in the historical centre of Camagüey, were modelled and analysed changing their height-to-width ratio and orientation. Our findings confirm the effect of varying courtyard tridimensional aspect ratios on outdoor thermal conditions. Aspect ratios higher than 1 are advisable, as they contribute to improve the courtyard thermal conditions in summer, by reducing the subzones in the courtyard where the Tmrt is above 45 °C. Orienting the courtyard's long axis away from the East-West results in a lower level of Tmrt, with reductions of up to 15.7 °C, for high aspect ratios. The obtained Tmrt patterns give information about the most suitable subzones within the courtyards, according to the time of day and season. The proposed design and usability recommendations could be included in renovation projects aimed at enhancing courtyards' thermal conditions and contributing to an improvement of the surrounding urban microclimate.
•Courtyard configuration has an evident impact on the improvement of human thermal comfort conditions at pedestrian level.•Better thermal conditions are obtained in courtyards with orientations N-S and NE-SW.•Aspect ratios lower than 1 are not recommended, unless they are provided with sun shading elements in their central areas.•The east side of N-S and E-W courtyards have better thermal condition in the morning, and the west side in the afternoon.
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.
•Street configurations has an evident impact on improving human thermal comfort conditions on open balconies.•Streets with axes oriented NS and SE-NW provide the best thermal conditions for open balconies.•EW streets evidence a high thermal stress (over 43,4% of the time) for balconies located in the north side of the street.•Open balconies below 12 m are the most comfortable, with acceptable thermal conditions between 50,4% and 82,5% of the time.
