Microclimate And Urban Thermal Comfort

This article presents a review of the existing literature regarding the design of urban spaces, microclimate and urban thermal comfort. The microclimate and thermal comfort in urban spaces, especially in cit-ies located in tropical regions, must be approached from the concepts and theories that allow understanding the incidence of microclimatic parameters and urban fabric on the sensation of thermal comfort and bioclimatization of the urban spaces. In this way, this document shows the significance of planning, urban design and microclimate of a city in tropical regions, exploring the classification of local climatic zones at an urban level, the urban heat island, urban thermal comfort, micro-climatic parameters such as air temperature, relative humidity, wind, solar radiation and natural lighting, vegetation and its characteriza-tion in urban spaces and the morphology of a cityEl presente artículo presenta una revisión de la literatura existente en cuanto al diseño de espacios urbanos, microclima y confort térmico urba-no. El microclima y confort térmico en espacios urbanos, especialmente en las ciudades localizadas en regiones tropicales, debe ser abordada a partir de los conceptos y teorías que permiten comprender la incidencia de los parámetros microclimáticos y tejido urbano sobre la sensación de confort térmico y bioclimatización de los espacios urbanos. De esta forma, en este documento se manifiesta la significación de la planifica-ción, el diseño urbano y microclima de una ciudad en regiones tropicales, explorando la clasificación de las zonas climáticas locales a nivel urba-no, la isla de calor urbana, el confort térmico urbano, los parámetros microclimáticos como temperatura del aire, humedad relativa, viento, radiación solar e iluminación natural, la vegetación y su caracterización en espacios urbanos y la morfología de una ciuda

Urban heat island of Madrid and its influence over urban thermal comfort

This work is part of the activities MODIFICA Project: Predictive model of the energy performance of residential buildings under conditions of urban heat island (BIA2013-41732-R). This project is funded by the Ministry of Economy and Competitiveness through the R + D + i, 2013 program, and the authors are involved in their development, together with the research group Bioclimatic Architecture in a Sustainable Environment - ABIO (UPM). The hypothesis of the project is the fact that the transformation of land for urban growth in the city of Madrid potentiates the effect of the urban heat island (UHI), which modifies substantially in the urban microclimate. The UHI is the result of the gradual replacement of natural Surface by the urban area, whose surfaces absorb more solar radiation. This, coupled with other anthropogenic factors, increase the air temperature and cause an increase in local temperature. The consequence is a modification of the urban microclimate that affects to the comfort conditions in urban space and to the energy performance of buildings and, therefore, to the quality of life of the inhabitants

Connecting the realms of urban form, density and microclimate

Av doktorgradsstudenter på norske universiteter, er det en fjerdedel som ikke fullfører innen normert tid. Det er lite forskning på hvorfor det er slik i Norge. Å øke gjennomstrømningen vil være nyttig for stipendiaten og har samfunnsøkonomisk gevinst. Denne studien har sett på faktorer som kan virke inn på engasjement og utbrenthet hos norske doktorgradsstudenter. Økt engasjement og mindre utbrenthet kan bidra til at flere fullfører innen normert tid og at færre hopper av doktorgraden. Først gjennomførte vi en kvalitativ studie hvor vi intervjuet 9 doktorgradsstudenter fra UiT Norges arktiske universitet. Vi spurte om hva de anså som stressfaktorer og ressurser i arbeidet deres. I tråd med internasjonal forskning opplevde studentene at sosial støtte fra veileder og forskningsgruppe var viktige ressurser. I tillegg var motivasjon og autonomi viktig for informantene våre. Jobb-familie-konflikt og liten tro på egen faglighet var stressorer i doktorgraden. Videre utførte vi en kvantitativ studie med et større utvalg fra til sammen fem universiteter (N = 256). For å finne krav og ressurser i arbeidet, benyttet vi jobbkrav-ressursmodellen. Våre funn var i tråd med modellen, som predikerer at høye krav gir mer utbrenthet, mens mye ressurser gir økt engasjement og mindre utbrenthet. De kvantitative resultatene bekreftet at sosial støtte og veiledning var viktige ressurser. Av krav var jobb-familie-konflikt fortsatt sentral, mens arbeidsintensitet framkom som en ny type krav. Et annet nytt funn, var at opplevd kompetanse delvis medierte effekten fra ressurser til engasjement, og den svekket i tillegg forholdet mellom krav og utbrenthet. Gjennom å styrke ressursene hos doktorgradsstudenter kan jobbengasjement øke og utbrenthet minske. Dette kan føre til økt produktivitet og mindre ønske om å slutte i jobben. Dette vil ha ekstra effekt hvis det også rettes fokus mot å styrke opplevd kompetanse hos stipendiaten. Disse tiltakene kan bidra til at flere fullfører doktorgraden innen normert tid og at færre dropper ut. Nøkkelord: norske doktorgradsstudenter, phd, jobbkrav-ressursmodellen, stress, utbrenthet, engasjement

Unification and Planning of Urban Public Spaces With Bioclimatic Conditions. Case Study Drama, Greece

The green spaces in the urban environment facilitate the movement of air masses that act as air refreshment in the wider region. The unification of urban open spaces and their enrichment with vegetation affect the micro-climate positively and act as a decisive factor for the increasing of urban thermal comfort, via the shading and the phenomenon of evapotranspiration. The planning of urban public spaces can support a habitat network encouraging the connectivity of the man-made environments with the surrounding natural ecosystems. The present paper aims to promote the unification of urban open spaces, with bioclimatic criteria by emphasizing the role of vegetation aiming the enhancement of living conditions in settlements. In particular is analysed the data collection like the proportion of building height with road width H/W, the road orientation and the solar access, the paving materials, the existent vegetation and concludes to an urban unification in a central part of Drama city in Northern Greece, by creating walkways and green corridors. The issue of solar access outdoors has been briefly discussed as an additional criterion in landscape designing the street. Design recommendations are also outlined for designing comfortable urban spaces.

Evaluating the Impact of the Urban Requalification Project of Praça Duque De Saldanha and Avenida Da República in Lisbon

UID/SOC/04647/2013 SFRH/BPD/76893/2011In dense urban areas, reducing traffic and increasing green areas is foreseen as a way of promoting urban comfort. Using the urban requalification project for Lisbon’s Avenidas Novas neighbourhood as a case study, the effects of vegetation on microclimate and urban comfort are evaluated. In this context, the ENVI-met software is used to model the present and the future urban scenario. The simulation results indicate: i) increased urban comfort in the morning and in the afternoon resulting from the decrease in temperature due to the presence of new green areas foreseen by the urban project; ii) a reduction of up to 3 degrees in the morning (9h) and up to 3 degrees in the afternoon (15h); iii) the model implemented in ENVI-met suits the urban and environmental characteristics of Lisbon and it is, therefore, desirable that future urban rehabilitation projects should consider ex ante simulation of this typepublishersversionpublishe

Design recommendations for the rehabilitation of an urban canyon in a subtropical climate region using aerial thermography and simulation tools

Outdoor public space is the setting for everyday social interaction where activities take place in order to satisfy collective urban needs. It is important to achieve climate-friendly urban design in order to ensure acceptable urban thermal comfort, especially in over-urbanised city centres during summer periods. In this research, an urban canyon street located in the historical centre of the subtropical city of Huelva (Spain) was analysed. After a survey carried out by in situ meteorological sensors and airborne infrared sensors (equipped on an unmanned aerial vehicle, UAV), the current thermal comfort was analysed in terms of PMV and PPD at different times of a typical summer day (11:00 h, 15:00 h and 19:00 h) with the aim of formulating design recommendations to improve its performance in terms of urban comfort. Then, thermal comfort was evaluated in different scenarios where feasible mitigation strategies (replacement of materiality, addition of vegetation and sun shading ele- ments) were applied to classify them according to their effectiveness using the ENVI-met simulation tool. The results of the current scenario showed that, due to its N-S orientation and its aspect ratio (H/W), the urban comfort depends drastically on the day hour variation. A comfortable thermal environment is achieved at all points of the urban canyon as a result of the shade generated by the buildings during the morning and afternoon. However, in the central hours of the day the feeling of thermal discomfort was alarming (PMV values of +3 and PPD values above 90%). The proposed mitigation measures showed a considerable improvement in urban thermal comfort, with the addition of vegetation being the most effective solution (with an improvement in PMV value of 42% and a reduction in PPD value of 43%). The combination of all the proposed measures in a single scenario showed encouraging results in the rehabilitation of public spaces in use.This work has been funded by the Research Center for Technology, Energy and Sustainability (CITES) at the University of Huelva. This work has been also funded by Proyecto SALTES (P20_00730): Smartgrid with reconfigurable Architecture for testing controL Techniques and Energy Storage priority. Programa Operativo FEDER 2014- 2020 Junta de Andalucia. Funding for open access charge: Universidad de Huelva/CBUA

Assessment of aerial thermography as a method of in situ measurement of radiant heat transfer in urban public spaces

Una propuesta de nuevas estrategias para la mejora del medio ambiente urbano, usando termografía aérea para el cálculo de la temperatura media radianteUrban public spaces are an essential part of the urban environment, supporting social relationships and pro- moting a healthy lifestyle among citizens. However, the high value of urban land has led to an over-urbanisation of cities, increasing urban heat stress and decreasing the number and size of public spaces. Rising air temper- atures in cities – known as the urban heat island effect (UHI) - combined with global warming, make public spaces less comfortable. For these reasons, there has been a growing concern to improve the thermal comfort of urban spaces. Thermal radiation is a determining factor in urban thermal comfort and is normally summarised in a value called mean radiant temperature (TMRT). In the past, conventional methods have been used to calculate it, such as net radiometers and globe thermometers. In recent years, the scientific community has used ground- based handheld thermal cameras for its quantification. However, there is a lack of literature on the use of aerial thermography for this purpose (i.e. an unmanned aerial vehicle (UAV) equipped with a thermal infrared device). Given this gap in the literature and the advantages in time, versatility and accuracy of these systems, this paper presents a new method for assessing the measurement of radiant heat transfer in a pedestrian urban space using aerial thermography. From the surface temperatures of the infrared imagery collected by the UAV, TMRT was estimated at multiple points in a pedestrian area of a subtropical city (Huelva, Spain) during a typical summer day. In order to verify accuracy of the proposed method to estimate the TMRT, a microclimate urban simulation was carried out using ENVI-met v5. The comparative analysis of the measured and simulated dataset verified the applicability of aerial thermography for the measurement of radiant heat transfer (with R2 values of 0.98 for the data set and 0.8 for the data of each time period). To conclude, new strategies were proposed to improve urban thermal comfort and to make cities more sustainable.Funding for open access charge: Universidad de Huelva/CBUA. Proyecto SALTES (P20_00730): Smartgrid with reconfigurable Architecture for testing controL Techniques and Energy Storage priority. Programa Operativo FEDER 2014-2020 Junta de Andalucia

Influencing factors of the thermal environment of urban green space

Several heat records have been broken in recent years and decades. Extreme high temperature not only damages human health, but also increases the risk of wildfires. As a common urban infrastructure, urban green space has been proved to have a cooling effect. In this study, the physical indicators and temperature data of 36 green spaces in Xi'an were collected, and the influence of different physical indicators of green spaces on their thermal environment was explored through correlation analysis. The results suggest that the area of green space should be between 0.6-0.7 square kilometers or the perimeter should range from 4000 to 4500 m in order to obtain the lowest internal temperature. When the area of water body in the green space is between 0.3-0.4 square kilometers or the perimeter is about 5000 m, its internal temperature is the lowest. Indicators of green space in the conclusion can be directly understood and referred by urban planners and policy makers. Results of this study thus have implications for improving urban thermal comfort by controlling the physical indicators of green space

Microclima y Confort Térmico Urbano

This article presents a review of the existing literature regarding the design of urban spaces, microclimate and urban thermal comfort. The microclimate and thermal comfort in urban spaces, especially in cities located in tropical regions, must be approached from the concepts and theories that allow understanding the incidence of microclimatic parameters and urban fabric on the sensation of thermal comfort and bioclimatization of the urban spaces. In this way, this document shows the significance of planning, urban design and microclimate of a city in tropical regions, exploring the classification of local climatic zones at an urban level, the urban heat island, urban thermal comfort, microclimatic parameters such as air temperature, relative humidity, wind, solar radiation and natural lighting, vegetation and its characterization in urban spaces and the morphology of a city.El presente artículo presenta una revisión de la literatura existente  en cuanto al diseño de espacios urbanos, microclima y confort térmico urbano. El microclima y confort térmico en espacios urbanos, especialmente en las ciudades localizadas en regiones tropicales, debe ser abordada a partir de los conceptos y teorías que permiten comprender la incidencia de los parámetros microclimáticos y tejido urbano sobre la sensación de confort térmico y bioclimatización de los espacios urbanos. De esta forma, en este documento se manifiesta la significación de la planificación, el diseño urbano y microclima de una ciudad en regiones tropicales, explorando la clasificación de las zonas climáticas locales a nivel urbano, la isla de calor urbana, el confort térmico urbano, los parámetros microclimáticos como temperatura del aire, humedad relativa, viento, radiación solar e iluminación natural, la vegetación y su caracterización en espacios urbanos y la morfología de una ciudad