Resiliencia al cambio climático del entorno construido en la región mediterránea del sur de Europa

El presente trabajo aborda la necesidad de cambio en los modos y formas de construcción de edificios residenciales, presentando la necesidad y resultados de implementar medidas energéticamente pasivas como un elemento fundamental a tener en cuenta dentro del diseño arquitectónico global. Esta importancia se justifica como una solución ante los problemas que se derivan del cambio climático que afectarán, y están afectando, al conjunto de la sociedad y con especial dureza a la población en situaciones de vulnerabilidad (población envejecida, en situación de pobreza energética y/o con minusvalías y enfermedades) Se ha querido localizar este estudio en la región mediterránea del Sur de Europa ya que esta zona presenta grandes retos debido a los tipos de clima que presenta, a las características presentes y futuras del conjunto de su población y a las previsiones de cambio climático que la sitúan como una de las zonas de Europa que peores consecuencias sufrirá, especialmente desde el punto de vista térmico (aumento de las temperaturas y de las olas de calor). Las estrategias energéticas pasivas en el diseño o rehabilitación de un edificio, constituyen el primer paso a considerar en la eficiencia energética de los edificios para alcanzar el objetivo a futuro de una arquitectura y ciudades resilientes. Dichas medidas vienen necesariamente definidas según las condiciones climáticas en las que se ubica el edificio, así como del patrón de uso de los ocupantes del edificio. Además, el bienestar de los usuarios junto con el confort interior de las viviendas son dos elementos fundamentales a tener en cuenta en la consecución de los objetivos ambientales. Esta investigación aborda la problemática descrita, basándose en la revisión bibliográfica de artículos indexados y libros relevantes, así como de aquellos organismos que trabajan específicamente en alguno de los aspectos (IPCC, WHO, EEA, UE, etc).This initial review is about the necessity of change the way of construction in residential buildings, presenting the necessity and results of implementing energy passive strategies as a fundamental element in architectural design. This importance is justified as a solution to the problems that derive from climate change that will affect, and is affecting, our society with special hardness on the population in situations of vulnerability (aging, people in a situation of energy poverty and / or with disabilities and diseases…). This study is focused in the Mediterranean region (South of Europe) because this zone presents great challenges, related with the type of climate that it presents, the present and future characteristics of its population and the predictions of climatic change that place it as one of the areas in Europe that will suffer the worst climate consequences, especially from the thermal point of view (the temperatures and heat waves will rise). Passive energy strategies, in the design or rehabilitation of a building, are the first step to achieve the future objective of a resilient architecture and cities. These strategies are necessarily defined according to the climatic conditions in which the buildings are located, as well as the pattern of use of the occupants of these buildings. In addition, the well-being of the users and the comfort in the homes are two fundamental elements to take into account to achieve the environmental objectives. This research is based on the bibliographic review of indexed articles and relevant books, as well as those organizations that work specifically on the topic of this review (IPCC, WHO, EEA, UE, etc)

Evaluation of thermal comfort and building form attributes in different semi-outdoor environments in a high-density tropical setting

In highly dense tropical cities, a semi-outdoor space (SOS) is frequently used as a social space within tall building forms where people can interact and connect. Thermal comfort in SOSs within tall buildings, however, may vary depending on the type and form attributes that define it. This study classifies 63 SOSs in four tall buildings of Singapore into five types based on literature review: perimeter buffers, sky terraces, horizontal breezeways, breezeway atria and vertical breezeways. Findings suggest that the five SOS types perform differently in terms of thermal comfort (based on PMV*), environmental parameters (air temperature, mean radiant temperature, relative humidity, and air velocity), and building form attributes (height-to-depth ratio, open space ratio, and green plot ratio). Of these five, vertical breezeways and horizontal breezeways are the most thermally comfortable for all activities during a typically warm hour. It is postulated that higher thermal comfort levels in these SOS types are linked to form attributes that enhance air velocity. This study examines the pros and cons of each SOS type in terms of thermal comfort in their role as communal spaces in tall buildings situated within a highly dense tropical city

Passive cooling design strategies as adaptation measures for lowering the indoor overheating risk in tropical climates

Year-round high temperatures and humidity in the Tropics, coupled with poor design decisions and climate change, can cause indoor environments to overheat, affecting health and increasing energy demand and carbon emissions. Passive cooling could help lower the indoor overheating risk. Given the gap in the relative influence of passive cooling design strategies on lowering the indoor overheating risk in tropical locations, this study investigated their impact in two warm tropical cities (i.e., Tegucigalpa and San Pedro Sula), considering both current and future climate scenarios, with a total of 3840 thermal simulations performed. Indoor overheating risk in apartment-type dwellings was assessed using two metrics (i.e., hours of exceedance and the indoor overheating degree), and considering fixed and adaptive thermal comfort limits. Simulation results show that the overheating risk can be significantly lowered in these tropical contexts using solely passive cooling strategies as heat adaptation measures. Multivariate regression models demonstrate that natural ventilation, wall absorptance, the solar heat gain coefficient, and semi-outdoor spaces have the greatest impact in lowering the risk in vertical social housing projects. This study emphasizes the importance of passive cooling and overheating protection design strategies in tropical building codes and building design while considering current and future risk

Difficulties in the energy renovation processes of district heating buildings. Two case studies in a temperate climate

Renovation at district scale is a key strategy to reduce CO2 emissions and energy consumptions by optimising the implementation of renewable energy sources and taking advantage of economies of scale. In this context, this paper focuses on assessing the positive impacts and difficulties after the energy rehabilitation of thermal envelopes in two buildings that belong to two different District Heating systems. The methodology is based on the comparative analysis of indoor temperatures data and energy consumption data of 17 monitored dwellings. The results showed a significant association between the improvement of envelopes and the increase of indoor temperatures in winter (β=0,644). Due to some technical and social barriers, the heating system was not regulated after the rehabilitation, so energy consumption was unnecessarily high, there were situations of indoor overheating in winter (maximum average indoor temperatures between 24-26°C) and these issues produced dissatisfaction on neighbours. In order to avoid these negative consequences, some recommendations are provided, such as informing neighbours about expectations in each step of the long rehabilitation process, reconsidering payments to promote the envelope rehabilitation but maintaining a fixed cost to protect vulnerable groups, and promoting post-occupational studies that contribute to the viability and up-date of this kind of District Heating systems

Encouraging natural ventilation to improve indoor environmental conditions at schools. Case studies in the north of Spain before and during COVID

The COVID pandemic has strongly affected daily life both in Spanish schools and worldwide. Providing the best environmental conditions for children allowing face-to-face learning with healthy and safe indoor spaces is a challenge. In the present study, empirical research about how these environmental conditions change with COVID is presented comparing the situation from March 2020 to January 2021. The methodology combines surveys conducted in nine schools with a case study in a selected school where a detailed monitoring of the building was developed during both heating seasons. This data ana- lyzes the impact of the new COVID prevention protocols on indoor environmental conditions (especially those related to natural ventilation). Results show a mean CO2 reduction of 1,400 ppm, having in the sec- ond term values around 1,000 ppm, although temperatures diminished nearly 2 °C to mean values of 18 °C. Evolution of temperature and CO2 concentration throughout the day was also analyzed, being these indoor conditions especially important for the children with poorer health. Mechanical ventilation with heating recovery should complement natural ventilation, at least during the coldest months or hours of the day, although systems have to be carefully designed and installed to work effectively

Industrialized Sunspace Prototype with Solar Heat Storage. Assessment of Post-Occupational Behaviour in Adaptive Facades.

The thermal performance of two passive solar components has been investigated. An attached sunspace with horizontal heat storage and another one with vertical thermal storage were designed in order to optimize the use of solar gains and its storage and distribution in an industrialized component. These sunspaces have been tested under real conditions, comparing their thermal performance with two commonly used components in residential buildings in Spain: a window and a double window making up an attached sunspace. Different series of experimental measurements were conducted in two test-cells exposed to outdoor conditions in Pamplona (Northern Spain). As a result, nine scenarios during winter 2011 and six during summer 2012 have been carried out, comparing all of the prototypes two by two with different use modes. Results show that a sunspace with heat storage takes advantage of the solar energy and improves the indoor thermal performance of the adjacent room during winter in a better way than a window or a simple sunspace, and that it also offers better performance in summer. The best results in winter and summer were obtained when an appropriate use of the component was performed, in concordance with outdoor conditions. Several thermal control keys for the use of these components are suggested

Resiliencia al cambio climático del entorno construido en la región mediterránea del sur de Europa

El presente trabajo aborda la necesidad de cambio en los modos y formas de construcción de edificios residenciales, presentando la necesidad y resultados de implementar medidas energéticamente pasivas como un elemento fundamental a tener en cuenta dentro del diseño arquitectónico global. Esta importancia se justifica como una solución ante los problemas que se derivan del cambio climático que afectarán, y están afectando, al conjunto de la sociedad y con especial dureza a la población en situaciones de vulnerabilidad (población envejecida, en situación de pobreza energética y/o con minusvalías y enfermedades) Se ha querido localizar este estudio en la región mediterránea del Sur de Europa ya que esta zona presenta grandes retos debido a los tipos de clima que presenta, a las características presentes y futuras del conjunto de su población y a las previsiones de cambio climático que la sitúan como una de las zonas de Europa que peores consecuencias sufrirá, especialmente desde el punto de vista térmico (aumento de las temperaturas y de las olas de calor). Las estrategias energéticas pasivas en el diseño o rehabilitación de un edificio, constituyen el primer paso a considerar en la eficiencia energética de los edificios para alcanzar el objetivo a futuro de una arquitectura y ciudades resilientes. Dichas medidas vienen necesariamente definidas según las condiciones climáticas en las que se ubica el edificio, así como del patrón de uso de los ocupantes del edificio. Además, el bienestar de los usuarios junto con el confort interior de las viviendas son dos elementos fundamentales a tener en cuenta en la consecución de los objetivos ambientales. Esta investigación aborda la problemática descrita, basándose en la revisión bibliográfica de artículos indexados y libros relevantes, así como de aquellos organismos que trabajan específicamente en alguno de los aspectos (IPCC, WHO, EEA, UE, etc).This initial review is about the necessity of change the way of construction in residential buildings, presenting the necessity and results of implementing energy passive strategies as a fundamental element in architectural design. This importance is justified as a solution to the problems that derive from climate change that will affect, and is affecting, our society with special hardness on the population in situations of vulnerability (aging, people in a situation of energy poverty and / or with disabilities and diseases…). This study is focused in the Mediterranean region (South of Europe) because this zone presents great challenges, related with the type of climate that it presents, the present and future characteristics of its population and the predictions of climatic change that place it as one of the areas in Europe that will suffer the worst climate consequences, especially from the thermal point of view (the temperatures and heat waves will rise). Passive energy strategies, in the design or rehabilitation of a building, are the first step to achieve the future objective of a resilient architecture and cities. These strategies are necessarily defined according to the climatic conditions in which the buildings are located, as well as the pattern of use of the occupants of these buildings. In addition, the well-being of the users and the comfort in the homes are two fundamental elements to take into account to achieve the environmental objectives. This research is based on the bibliographic review of indexed articles and relevant books, as well as those organizations that work specifically on the topic of this review (IPCC, WHO, EEA, UE, etc)

Evaluation of the energy consumption and overheating of homes in Miami, Guayaquil and Tenerife

Year after year, global warming is elevating temperatures all over the world, causing indoor overheating environments that are inhabitable, and increasing energy demand in housing. Given this global concern, the aim of the study was to evaluate the thermal behavior of the house in the cities of Miami, Guayaquil and Tenerife, by a comparison assisted with a simulation for their indoor overheating hours and cooling demand, considering their climates, energy efficiency codes, and construction systems. These were: Miami, with two models (M1 with timber frame as the thermal envelope and M2 with a concrete block system), Guayaquil, with two models (G1 with the limitations for a dwelling with cooling system and G2 without it), and Tenerife with only one model. As a result, was found that Miami is the case with the higher consumption, which has a higher energy demand in a house of timber wall system than in a house of concrete block system, due to the thermal inertia. Despite that both models have the same usage time for the cooling system, meaning that more power was needed to reach the thermal comfort. Then, Guayaquil and Tenerife, are the cases that follows, with less consumption. While, according to the UNE EN 16798 methodology, in the indoor overheating hour evaluation in a year, Miami has the higher cases with a 31.43% of its hours in overheating for the timber frame system and a 22.88% for the concrete block system, followed by two cases in Guayaquil, with 4.2%, other with none, and also Tenerife with 2.43%. Nevertheless, the study showed that energy consumption is not necessarily related to the indoor overheating hours that a house could have. Given that, in the case of Guayaquil, where it doesn’t have any indoor overheating hour in all year, while Tenerife, with a similar energy consumption, has 2.43% of its hours in overheating. Due to the different parameters that the UNE follows in comparison with the cooling setpoints given by the CTE-DB-HE all over the year for the respective cases, because of their long warm seasons. Therefore, the study analyses the limits establish by the Spanish normative in relation to overheating, showing an overestimation assessment if the results with the UNE methodology are compared