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).

Se desarrolla una metodología que permite la localización de áreas urbanas que se encuentran en situación de pobreza energética. Para ello es necesario analizar datos geolocalizados de la relación entre los ingresos medios por hogar y los consumos energéticos residenciales para cada área urbana. La metodología se aplica al caso de la ciudad de Madrid (España). En el proceso de estimación del coste de los servicios energéticos por hogar se desentrama el peso que juegan los distintos factores que influyen en él: la calidad de la construcción, las instalaciones térmicas más utilizadas, los tipos de suministro de energía empleados para satisfacer las necesidades del hogar y la estructura tarifaria del sector energético español. Se concluye que la interacción de estos factores provoca que los hogares incluidos en los tramos de renta mínima estén en riesgo de pobreza energética de manera independiente de la eficiencia energética de la vivienda que ocupan. Esto apunta a la necesidad de desarrollar políticas públicas específicas para combatir la pobreza energética de manera complementaria a los planes para la rehabilitación energética de viviendas.

An innovative system based on the Trombe Wall concept is under development to improve energy efficiency in buildings in different climatic conditions. The system takes advantage of the variable optical properties of a thermochromic mortar coating on the façade to optimize thermal behaviour. The mortar is based on the addition of organic thermochromic pigments to the cementitious matrix and is characterized by a high solar reflectance for temperatures higher than a nominal colour change value (Tc) and a low solar reflectance for lower temperatures. Materials potentially useful for this innovative system were analysed in this work. As prepared thermochromic mortar specimens, mortar specimens coated with different UV protecting products and mortar specimens covered by filter glasses with different optical responses were exposed to controlled outdoor environmental conditions during several days. Surface and environmental temperatures were monitored during the experiment. Moreover, reflectance spectra of the samples were recorded every day early in the morning, when the environmental temperature is significantly lower than Tc, and in the afternoon, when it is significantly higher than this value. Most suitable materials for the intended application were defined from an analysis of the optical and thermal properties of these specimens and their durability.