Solar access assessment in dense urban environments: the effect of intersections in an urban canyon

The urban canyon model has been recurrently used as a basis for many solar access studies. However, its conception as endless structures disregards the effect of street intersections, despite being characteristic elements of urban fabrics. This paper aims to evaluate the impact of street discontinuities on solar access over building façades. The potential of crossings to increase the available radiation has been assessed through computer simulations in dense urban environments in a Mediterranean location. For the cases studied, results show that local effects of an intersection almost disappear beyond a speci¿c distance for each aspect ratio, which can be helpful to determine the suitable level of detail for solar analyses at an urban fabric scale.Postprint (published version

Termografía del cañón urbano : uso de la perspectiva para una evaluación térmica global de la calle

Premi Extraordinari de Doctorat, promoció 2018-2019. Àmbit d’Arquitectura, Urbanisme i EdificacióMany of the citizen's daily activities take place in the streets. Climatic conditions in between buildings largely affect the user’s comfort of these spaces, and, consequently, the human perception of the city environment. Additionally, the climate at street level influences environmental conditions inside buildings, affecting, therefore, the amount of energy needed to achieve indoor comfort and, by extension, the global city energy consumption. Street environmental conditions are the result of complex energy exchanges between the air and built surfaces. From a thermal point of view, the result of this balance is expressed by the surface temperature. This doctoral thesis investigates the possibilities of thermographic time-lapses as a tool for the analysis of the time evolution and the space distribution of temperatures over the urban canyon surfaces. The study focuses on streets within compact urban tissues, built morphologies whose thermal behavior is not well-understood yet. This research explores what can be learned about the thermal performance of these urban canyons only with a commercial infrared camera operated by one person for a day, feasible conditions for the early stage of urban projects. With such limited resources, the geometry of the street leads to the shot of thermographies in perspective to maximize the information obtained from an individual image. This approach, which can be considered innovative among the uses of thermography technique in the built environment, introduces some challenges regarding the results interpretation. The most important one is the presence of a temperature deviation between frontal and oblique views. Several experimental tests help to demonstrate that, within compact urban canyons, advantages of the global thermal view of the street clearly compensate the slight accuracy loss associated to the perspective view. Based on this approach, this thesis studies the impact of two kind of architectural interventions on the thermal behavior of street surfaces: the change in the façade reflectivity and the installation of shading devices at a street scale. To perform these thermal analyses, it is necessary to develop a new method for the acquisition and post-processing of thermographic image sequences. This method is implemented on several streets with similar geometry, but with differences regarding its material composition and design, allowing the comparison among the case studies. From a methodological point of view, it is stated that the method developed in the thesis constitutes an effective tool for a better understanding of the thermo-radiative phenomena taking place within the streets. From an architectural point of view, results demonstrate the potential of the two interventions assessed to modify the street radiative environment, both in short and longwave, as shown by the remarkable differences in surface temperature found between cases. In the current context of environmental and energy crisis, knowing the characteristics of the microclimate at this scale, and the mechanisms that drive it, is a priority to guide urban projects towards more sustainable models.Muchas de las actividades diarias de los ciudadanos tienen lugar en la calle. De las condiciones ambientales existentes en estos espacios depende, en gran medida, el grado de confort de sus usuarios y, con ello, su percepción ambiental de la ciudad. Además, el clima a nivel de calle influye sobre el comportamiento energético de los edificios, afectando, por tanto, a la cantidad de energía necesaria para lograr el confort en su interior y, por extensión, al consumo energético global de la ciudad. Las condiciones ambientales de la calle son consecuencia de complejos intercambios de energía entre el aire y sus superficies. A nivel térmico, el resultado de este balance se expresa mediante la temperatura superficial. En esta tesis doctoral, se investigan las posibilidades de las secuencias de termografías como herramienta de análisis de la evolución temporal y distribución espacial de las temperaturas sobre las superficies del cañón urbano. La investigación se centra en calles de tejidos urbanos compactos, morfologías cuyo comportamiento térmico aún no es del todo comprendido. Se plantea qué se puede aprender sobre el ambiente térmico de este tipo de calles, contando con una cámara comercial, un técnico y un día de medición, condiciones asimilables a la etapa inicial de proyecto. Contando con estos recursos, la propia geometría del entorno lleva a tomar las termografías en perspectiva para maximizar la información obtenida en cada imagen. Este enfoque, innovador dentro de los usos habituales de la termografía en ambientes construidos, introduce, sin embargo, una serie de retos en la interpretación de los resultados. El más importante es la existencia de una desviación entre las temperaturas obtenidas desde tomas frontales y oblicuas. Gracias a diversos tests experimentales, se comprueba que, en el caso de cañones urbanos compactos, las ventajas de tener una visión global térmica de la calle compensan sobradamente la ligera disminución de la precisión introducida por la perspectiva. Partiendo de este enfoque, esta tesis estudia los efectos sobre el comportamiento térmico de las superficies del cañón urbano de dos tipos de intervenciones arquitectónicas: el cambio de la reflectividad de las fachadas y la instalación de dispositivos de sombra a escala de calle. Para llevar a cabo estos análisis térmicos, es necesario desarrollar una metodología propia de adquisición y procesamiento de secuencias termográficas. Dicho método se aplica en diversas calles, similares en su geometría pero diferentes desde un punto de vista material y de diseño, lo que permite comparar térmicamente los distintos casos de estudio. Desde el punto de vista metodológico, se concluye que el método diseñado constituye una herramienta eficaz para mejorar nuestra comprensión de los fenómenos térmico-radiativos que tienen lugar a la escala de calle. A nivel arquitectónico, los resultados muestran el potencial de ambas intervenciones para modificar el ambiente radiativo del cañón urbano, tanto en ondas cortas como largas, registrándose variaciones notables de la temperatura superficial. En el actual contexto de crisis energética y ambiental, conocer las características del microclima de la calle, y los mecanismos que lo gobiernan, resulta prioritario para guiar el proyecto urbano hacia modelos más sosteniblesAward-winningPostprint (published version

Termografía del cañón urbano : uso de la perspectiva para una evaluación térmica global de la calle

Many of the citizen's daily activities take place in the streets. Climatic conditions in between buildings largely affect the user’s comfort of these spaces, and, consequently, the human perception of the city environment. Additionally, the climate at street level influences environmental conditions inside buildings, affecting, therefore, the amount of energy needed to achieve indoor comfort and, by extension, the global city energy consumption. Street environmental conditions are the result of complex energy exchanges between the air and built surfaces. From a thermal point of view, the result of this balance is expressed by the surface temperature. This doctoral thesis investigates the possibilities of thermographic time-lapses as a tool for the analysis of the time evolution and the space distribution of temperatures over the urban canyon surfaces. The study focuses on streets within compact urban tissues, built morphologies whose thermal behavior is not well-understood yet. This research explores what can be learned about the thermal performance of these urban canyons only with a commercial infrared camera operated by one person for a day, feasible conditions for the early stage of urban projects. With such limited resources, the geometry of the street leads to the shot of thermographies in perspective to maximize the information obtained from an individual image. This approach, which can be considered innovative among the uses of thermography technique in the built environment, introduces some challenges regarding the results interpretation. The most important one is the presence of a temperature deviation between frontal and oblique views. Several experimental tests help to demonstrate that, within compact urban canyons, advantages of the global thermal view of the street clearly compensate the slight accuracy loss associated to the perspective view. Based on this approach, this thesis studies the impact of two kind of architectural interventions on the thermal behavior of street surfaces: the change in the façade reflectivity and the installation of shading devices at a street scale. To perform these thermal analyses, it is necessary to develop a new method for the acquisition and post-processing of thermographic image sequences. This method is implemented on several streets with similar geometry, but with differences regarding its material composition and design, allowing the comparison among the case studies. From a methodological point of view, it is stated that the method developed in the thesis constitutes an effective tool for a better understanding of the thermo-radiative phenomena taking place within the streets. From an architectural point of view, results demonstrate the potential of the two interventions assessed to modify the street radiative environment, both in short and longwave, as shown by the remarkable differences in surface temperature found between cases. In the current context of environmental and energy crisis, knowing the characteristics of the microclimate at this scale, and the mechanisms that drive it, is a priority to guide urban projects towards more sustainable models.Muchas de las actividades diarias de los ciudadanos tienen lugar en la calle. De las condiciones ambientales existentes en estos espacios depende, en gran medida, el grado de confort de sus usuarios y, con ello, su percepción ambiental de la ciudad. Además, el clima a nivel de calle influye sobre el comportamiento energético de los edificios, afectando, por tanto, a la cantidad de energía necesaria para lograr el confort en su interior y, por extensión, al consumo energético global de la ciudad. Las condiciones ambientales de la calle son consecuencia de complejos intercambios de energía entre el aire y sus superficies. A nivel térmico, el resultado de este balance se expresa mediante la temperatura superficial. En esta tesis doctoral, se investigan las posibilidades de las secuencias de termografías como herramienta de análisis de la evolución temporal y distribución espacial de las temperaturas sobre las superficies del cañón urbano. La investigación se centra en calles de tejidos urbanos compactos, morfologías cuyo comportamiento térmico aún no es del todo comprendido. Se plantea qué se puede aprender sobre el ambiente térmico de este tipo de calles, contando con una cámara comercial, un técnico y un día de medición, condiciones asimilables a la etapa inicial de proyecto. Contando con estos recursos, la propia geometría del entorno lleva a tomar las termografías en perspectiva para maximizar la información obtenida en cada imagen. Este enfoque, innovador dentro de los usos habituales de la termografía en ambientes construidos, introduce, sin embargo, una serie de retos en la interpretación de los resultados. El más importante es la existencia de una desviación entre las temperaturas obtenidas desde tomas frontales y oblicuas. Gracias a diversos tests experimentales, se comprueba que, en el caso de cañones urbanos compactos, las ventajas de tener una visión global térmica de la calle compensan sobradamente la ligera disminución de la precisión introducida por la perspectiva. Partiendo de este enfoque, esta tesis estudia los efectos sobre el comportamiento térmico de las superficies del cañón urbano de dos tipos de intervenciones arquitectónicas: el cambio de la reflectividad de las fachadas y la instalación de dispositivos de sombra a escala de calle. Para llevar a cabo estos análisis térmicos, es necesario desarrollar una metodología propia de adquisición y procesamiento de secuencias termográficas. Dicho método se aplica en diversas calles, similares en su geometría pero diferentes desde un punto de vista material y de diseño, lo que permite comparar térmicamente los distintos casos de estudio. Desde el punto de vista metodológico, se concluye que el método diseñado constituye una herramienta eficaz para mejorar nuestra comprensión de los fenómenos térmico-radiativos que tienen lugar a la escala de calle. A nivel arquitectónico, los resultados muestran el potencial de ambas intervenciones para modificar el ambiente radiativo del cañón urbano, tanto en ondas cortas como largas, registrándose variaciones notables de la temperatura superficial. En el actual contexto de crisis energética y ambiental, conocer las características del microclima de la calle, y los mecanismos que lo gobiernan, resulta prioritario para guiar el proyecto urbano hacia modelos más sostenible

Characterization of façade fenestration for energy studies within the “Eixample” urban tissue of Barcelona

This paper explores the possibility of characterising the degree of fenestration of a certain city by studying a limited building sample. For the case study of the Eixample district of Barcelona, window-to-wall ratio (WWR) guiding values are provided and the role of the date of construction and the façade orientation is assessed regarding the opening size. Results indicate that not only average WWR values but also dispersion indicators should be provided to adequately describe façade fenestration. The age of construction has found to be a helpful parameter to approximate representative WWR values of a tissue reducing the uncertainty.Postprint (published version

The use of thermography to highlight the relationship between air and surface temperatures in urban scenes

The correlation between air and surface temperatures is recurrently used as a descriptor of the urban climate within built environments. The aim of this paper is to explore the possibilities of time-lapse thermography to visualize this relationship in time and space. To this end, thermograms are colorized using a relative-to-air temperature scale, instead of the usual absolute one. This approach was tested for two deep urban canyons belonging to cities with different climates. Relative-to-air thermography has two main advantages: it facilitates comparisons between the thermal responses of urban scenes under different climates and makes convective energy exchanges more comprehensive.Peer ReviewedPostprint (author's final draft

Façade design and energy demand: fenestration indexes from an urban Approach

Façade design has significant effects on inner conditions of spaces and also on the energy needs to achieve user’s comfort. In this regard, the proportion of glazed surfaces to opaque ones plays a key role. Although the link between the fenestration ratio and energy demand for a space has been widely addressed in literature, a considerable number of these studies were based on isolated models, disregarding the effect of the urban surroundings. The aim of this paper is to provide insights on the impact of the window-to-wall ratio (WWR) on thermal energy demands taking into consideration a specific urban context. The Eixample district of Barcelona, with Mediterranean temperate climate, has been selected as the case study. Heating and cooling energy needs have been evaluated for a single residential space by means of computer simulations in Design Builder for different positions within the tissue. Results show that, from a thermal point of view, the design of façade openings within an urban context should vary depending on the orientation and the degree of obstruction, as a reflection of the differences in energy balance within the building envelope.Postprint (published version

Procedural modeling buildings for finite element method simulation

Finite element methods for heat simulation at urban scale require mesh-volume models, where the meshing process requires a special attention in order to satisfy FEM requirements. In this paper we propose a procedural volume modeling approach for automatic creation of mesh-volume buildings, which are suitable for FEM simulations at urban scale. We develop a basic rule-set library and a building generation procedure that guarantee conforming meshes. In this way, urban models can be easily built for energy analysis. Our test-case shows a street created with building prototypes that fulfill all the requirements for being loaded in a FEM numerical platform such as Cast3M (www-cast3m.cea.fr).Postprint (published version

Characterization of solar access in mediterranean cities: oriented sky factor

The link between city morphology and urban energy consumption, although proved, requires further research. In that sense, the analysis of parameters describing the urban texture may be a useful approach for energy assessment at a city scale. Some geometrical parameters have been used to study urban energy aspects related to the radiative phenomena, such as heat island or even a rough indicator of solar energy availability in locations where direct radiation is not determining. This paper aims to explore the correlation between one of these parameters -the Sky Factor (SF)- and direct solar radiation over facades, as a characterization tool of solar access within an urban context. Barcelona, a Mediterranean city where direct sunlight and the built environment density are deciding factors, has been chosen as case study. At different points of the facade for several urban canyons, SF value and direct solar radiation for different orientations and times of the year have been computed using Heliodon software. Both results have been related one to another and it has been found that, for a specific latitude, it is possible to define a smooth dependence between these parameters, if the orientation is taken into account. This paper shows that, beyond the SF threshold of 0.42, direct solar radiation on the facade reaches an almost asymptotic value for all orientations and times of the year.Postprint (published version

Variability in Phelan-McDermid Syndrome in a Cohort of 210 Individuals

Phelan-McDermid syndrome; Intellectual disabilities; Subtelomeric deletion syndromeSíndrome de Phelan-McDermid; Discapacidades intelectuales; Síndrome de deleción subteloméricaSíndrome de Phelan-McDermid; Discapacitats intel·lectuals; Síndrome de deleció subtelomèricaPhelan-McDermid syndrome (PMS, OMIM# 606232) results from either different rearrangements at the distal region of the long arm of chromosome 22 (22q13.3) or pathogenic sequence variants in the SHANK3 gene. SHANK3 codes for a structural protein that plays a central role in the formation of the postsynaptic terminals and the maintenance of synaptic structures. Clinically, patients with PMS often present with global developmental delay, absent or severely delayed speech, neonatal hypotonia, minor dysmorphic features, and autism spectrum disorders (ASD), among other findings. Here, we describe a cohort of 210 patients with genetically confirmed PMS. We observed multiple variant types, including a significant number of small deletions (<0.5 Mb, 64/189) and SHANK3 sequence variants (21 cases). We also detected multiple types of rearrangements among microdeletion cases, including a significant number with post-zygotic mosaicism (9.0%, 17/189), ring chromosome 22 (10.6%, 20/189), unbalanced translocations (de novo or inherited, 6.4%), and additional rearrangements at 22q13 (6.3%, 12/189) as well as other copy number variations in other chromosomes, unrelated to 22q deletions (14.8%, 28/189). We compared the clinical and genetic characteristics among patients with different sizes of deletions and with SHANK3 variants. Our findings suggest that SHANK3 plays an important role in this syndrome but is probably not uniquely responsible for all the spectrum features in PMS. We emphasize that only an adequate combination of different molecular and cytogenetic approaches allows an accurate genetic diagnosis in PMS patients. Thus, a diagnostic algorithm is proposed.REDES/FIBHULP08. FIBHULP PI: 2735. FIBHULP Auchan Reserch Project. FIBHULP. Raregenomics (B2017/BMD-3721)

Familial imbalance in 16p13.11 leads to a dosage compensation rearrangement in an unaffected carrier

Background: We and others have previously reported that familial cytogenetic studies in apparently de novo genomic imbalances may reveal complex or uncommon inheritance mechanisms. Methods: A familial, combined genomic and cytogenetic approach was systematically applied to the parents of all patients with unbalanced genome copy number changes. Results: Discordant array-CGH and FISH results in the mother of a child with a prenatally detected 16p13.11 interstitial microduplication disclosed a balanced uncommon rearrangement in this chromosomal region. Further dosage and haplotype familial studies revealed that both the maternal grandfather and uncle had also the same 16p duplication as the proband. Genomic compensation observed in the mother probably occurred as a consequence of interchromosomal postzygotic nonallelic homologous recombination. Conclusions: We emphasize that such a dualistic strategy is essential for the full characterization of genomic rearrangements as well as for appropriate genetic counselingFISH and aCGH materials were supported by grant 08/PI1207 from Fondo de Investigaciones Sanitarias (FIS) and research project ENDOSCREEN (S2011/BMD-2396) from Comunidad de Madri