• Energy Research

In Press. Most of the existing buildings in Spain lack any thermal insulation in their envelope. They are in urgent need to be refurbished to reduce their energy consumption. The standard solution for the rehabilitation of facades is to incorporate thermal insulation materials to reduce heat transmission. This work proposes an extension of the conventional approach: the installation of Trombe walls on sunny facades incorporating an outer layer of thermochromic mortar, the thermochromic Trombe wall (TTW). This improves the energy performance of the existing buildings by enhancing their solar gains. This paper describes the design and configuration of the new TTW system. While traditional solutions can be evaluated with a simple heat transfer equation, a complex energy model is needed to evaluate TTW. Energy simulation is used to determine parameters that influence thermal performance. Thermochromic mortar transition temperature is designed to achieve maximum efficiency. The results obtained from the parametric study were used to determine the aspects of the construction of the first prototype on a laboratory test cell. The information obtained from the experiment will be used for the calibration of the energy model that will establish the potential for the incorporation of the TTW to the existing buildings. This work is part of the tasks developed for the project BIA2014-56827-R ‘Development of an intelligent coating mortar based on thermochromic ecoefficient cements (MICET)’ funded by Ministerio de Economía y Competitividad (Spanish Ministry of Economy, Industry and Competitiveness). The construction system analysis was produced under funding of the Spanish Ministry of Economy and Competitiveness project BIA 2017-83231-C2-1-R: ‘HABITA-RES: Nueva herramienta integrada de evaluación para áreas urbanas vulnerables. Hacia la autosuficiencia energética y a favor de un modelo de habitabilidad biosaludable’. Peer reviewed

The confinement by COVID-19 has meant a re-reading of housing for Spanish households, resulting in the only available and safe space to carry out daily activity. This complex phenomenon has generated a completely different way of inhabiting it, as well as of relating to domestic spaces. For this reason, the home perception and its characteristics must be evaluated, highlighting those perceived as deficiencies, or as preferences in such an unusual context as lockdown, where the experience was different depending on the dwelling characteristics, and the family in question. To deepen in this double perception home-dwelling, a mixed method was used, with two online forms. The first is a quantitative questionnaire, while the second asks the participants for photographs and narratives about such images. More than 1800 surveys and 785 qualitative responses were obtained. From both approaches, the joint discourse arose, allowing an exploratory analysis of the current situation of the Spanish residential park, and the resilience demonstrated in this period by both households and their usual dwellings. This study should facilitate the development of new proposals on housing in contexts similar to the COVID-19 pandemic.

The research conducted under HABITA-RES explored the advisability of the integrative refurbishment of urban neighbourhoods on the outskirts of Madrid built between the end of the Civil War in 1939 and the enactment of the country’s first building code on the indoor environment in 1979. Characterised by highly inefficient buildings, many such neighbourhoods are listed as vulnerable urban areas. The study described hereunder analysed the feasibility of their conversion to energy self-sufficiency to improve residents’ environment, social circumstances and health. European directives and domestic legislation on energy production are introducing increasingly demanding requirements geared to achieving nearly zero energy buildings in 2020 and cities’ carbon neutrality by target year 2050. Possible approaches to achieve those ends were assessed under this study. The theoretical model used was validated with detailed information collected in situ on both social circumstances and energy efficiency. Designed to study improvement strategies for both individual and groups of buildings, the model prioritises passive improvements to lower demand. The findings will enable residents in such neighbourhoods to participate actively in improvement measures and access information on their costs and benefits.

This article analyses the situation that prevailed in 12 dwellings located on the outskirts of Madrid during Spain’s state of emergency. How did 24/7 occupation affect the quality of indoor air and power consumption patterns? The mixed method used (surveys and instrumental monitoring) pragmatically detected the variation in consumption, comfort and indoor air quality patterns before and during the COVID-19 pandemic. The characteristics initially in place and household predisposition had a conclusive effect on such variations. The starting conditions, including household composition, habits and the way daily activities were performed, differed widely, logically affecting power consumption: 8/12 case studies increase occupancy density by more than 25 percent; 11/12 improve thermal comfort; 10/12 improve air quality but not necessarily translate in a sufficient ventilation practices; air quality was lower in the bedrooms on the whole; only 4/12 case studies use the potential of passive measures; only one household adopted energy savings strategies; 10/12 case studies increase electric power consumption but none of the dwellings was fitted with a renewable power generation system. The conclusion drawn is that, despite starting conditions differing widely, household composition, habits (including performance of daily activities performance) and power consumption also played an active role in the end result. This approach allowed to integrate qualitative and quantitative findings on indoor environmental quality (IEQ), energy use and households’ behavior. The objective data on the energy situation of the case studies not only is useful for the study, but also for potential enrollment in energy rehabilitation programs, such as the European Regional Development Fund (ERDF).

Este trabajo pretende realizar aportaciones de interés para reducir la brecha existente entre el comportamiento energético real y previsto en edificios. Tiene como principal objetivo establecer modelos predictivos que relacionen el consumo eléctrico de climatización para mantener unas determinadas condiciones operacionales en el ambiente interior, según sea el clima exterior, en función de la solución de fachada. Esos modelos predictivos se obtienen para módulos de ensayo en la que toda su envolvente es adiabática, a excepción de la fachada que se quiere ensayar. Tres soluciones de fachada han sido consideradas: una base que se corresponde con una solución de doble hoja de ladrillo con cámara de aire intermedia, la solución más común en viviendas plurifamiliares en España que fueron construidos entre 1940 y 1980, previamente a la primera normativa que, con carácter global, limitaba la demanda energética en los edificios; y dos soluciones de rehabilitación de la fachada anterior muy frecuentemente utilizadas: Fachada Ventilada y ETICS. Usando los datos de monitorización de los consumos eléctricos de equipos de climatización en esos tres módulos, se generan esos modelos predictivos, tanto para el periodo de verano como el de invierno, que son rectas de regresión lineal cuyas ecuaciones se enuncian, así como sus principales parámetros estadísticos.

During spring 2020, the world was shocked at the imminent global spread of SARS-CoV-2, resorting to measures such as domestic confinement. This meant the reconfiguration of life in an unusual space; the home. However, not all households experienced it in the same way; many of them were vulnerable. A general increase in energy consumption and discomfort in many cases, led these families to suffer the ravages of confinement. This study analyzes the energy and comfort situation for the Madrid (Spain) population, according to the configuration of the homes, the characteristics of the dwellings, the vulnerability index by district, and energy poverty (measured with the 10% threshold of energy expenditure of home incomes). The results show a greater exposure, in confinement, of vulnerable and energy-poor households to scenarios of discomfort in the home, to which they could not respond, while energy consumption inevitably increased. Driven by need, energy-poor homes applied certain saving strategies, mainly resorting to thermal adaptation with clothing. This study shows the risk these households experienced in the face of an extreme situation, and invites reflection on preventive and containment measures that aim to avoid harming the disadvantaged in the future; harm that would also entail serious consequences on the health of their cohabitants.