Search

The energy budget of households, linked to residential energy consumption (REC), serves as a critical indicator of quality of life and economy trends. Despite the lack of widely available accurate statistics at regional or smaller scales, they are of crucial interest for a better understanding of the features influencing REC and its impact on energy poverty, wellbeing, and the climate crisis. This research aims to present a new information model for predictive parameters and REC forecasting through an innovative use of available open data. Geoprocessing, data mining, and machine learning clustering algorithms were applied to open datasets of location, population, and residential building stock parameters highly correlated with their REC, on the ensemble of 785 municipalities of Andalusia, Spain. The model identified 65 clusters of towns sharing the same potential REC, with 73% of the population concentrated in 10 of these. The resulting data-driven bottom-up model of provincial REC had a mean absolute error of only 0.63%. Furthermore, it provided the territorial distribution, with local resolution, of the identified clusters of cities with similar characteristics. This methodology, with a flexible regional- to city-scale analysis, provides knowledge generation that offers numerous practical applications for energy policy planning. Its future implementation would assist stakeholders and policymakers in enhancing the performance and decarbonization of the residential building stock.

The study of energy consumption in buildings, particularly residential ones, brings with it significant socio-economic and environmental implications, as it accounts for approximately 40% of CO2 emissions, 18% in the case of residential buildings, in Europe. On a number of levels, energy consumption serves as a key parameter in urban sustainability indicators and energy plans. Access to data on energy consumption is crucial for energy planning, management, knowledge generation, and awareness. Urban Building Energy Models (UBEMs), which are emerging tools for simulating energy consumption at neighborhood scale, allow for more efficient intervention and energy rehabilitation planning. However, UBEM validation requires reliable reference data, which are often challenging to obtain at urban scale due to privacy concerns and data accessibility issues. Recent advances, such as automation and open data utilization, are proving promising in addressing these challenges. This study aims to provide a standardized UBEM validation process by presenting a case study that was carried out utilizing open data to develop bottom-up engineering models of residential energy demand at urban scale, with a resolution level of individual buildings, and a subsequent adjustment and validation using reference tools. This study confirms that the validated GIS-UBEM model heating and cooling demands and consumption fall within the confidence bands of ±15% and ±12.5%, i.e., the confidence bands required for the approval of official alternative simulation methods for energy certification. This paves the way for its application in urban-scale studies and practices with a well-established margin of confidence, covering a wide range of building typologies, construction models, and climates comparable to those considered in the validation process. The primary application of this model is to determine the starting point and subsequent evaluation of improvement scenarios at a district scale, examining is

The validated influence of urban biophysical structure on environmental processes within urban areas has heightened the emphasis on studies examining morphological patterns to determine precise locations and underlying causes of urban climate conditions. The present study aims to characterise morphological patterns describing the distribution of Land Surface Temperature (LST) based on a prior classification of biophysical variables, including urban density (building intensity and average height), surface characteristics, shortwave solar radiation (broadband albedo), and seasonal variations in vegetation cover (high, medium, and low levels), retrieved from multisource datasets. To describe the distribution of LST, the variables were calculated, classified, and subsequently, analysed individually and collectively concerning winter and summer LST values applied in an urban neighbourhood in Madrid, Spain. The results from the analytical approaches (observation, correlations, and multiple regressions) were compared to define the morphological patterns. The selection of areas resulting from the morphological patterns with the most unfavourable LST values showed agreement of up to 89% in summer and up to 70% for winter, demonstrating the feasibility of the methods applied to identify priority areas for intervention by season. Notably, low and high vegetation levels emerged as pivotal biophysical characteristics influencing LST distribution compared to the other characteristics, emphasising the significance of integrating detailed seasonal vegetation variations in urban analyses.

Fuel poverty rates are high in southern Europe, particularly in social housing, despite the enormous potential for capturing solar power inherent in the roofs of apartment buildings. The in situ generation, distribution and consumption of photovoltaic energy carry obvious advantages including vastly improved efficiency attendant upon the reduction in distribution-related losses and costs, and the energy empowerment afforded lower income communities. The primary drawback is the imbalance between photovoltaic production patterns and users’ actual needs (peak consumption vs. peak generation). That mismatch is difficult to reconcile without resorting to energy storage or net metering, both of which entail grid involvement and greater management complexity. The present study introduces a methodology for analysing residential archetypes to determine the values of the parameters essential to optimising photovoltaic energy production and use. The aim is to determine where excess generation can be shared with other users in the vicinity and optimally pool residential rooftop facilities to meet community-scale energy demand, ultimately enhancing such disadvantaged neighbourhoods’ self-sufficiency. The case study discussed defines archetypes for just such a neighbourhood in Madrid, Spain. The solar energy production potential of the example is promising for its application in large southern European cities, with self-sufficiency rates obtained ranging from 15% to 25% and self-consumption rates from 61% to 80%.

The indoor environment in non-university classrooms is one of the most analyzed problems in the thermal comfort and indoor air quality (IAQ) areas. Traditional schools in southern Europe are usually equipped with heating-only systems and naturally ventilated, but climate change processes areboth progressively increasing average temperatures and lengthening the warm periods. In addition,air renewal is relayed in these buildings to uncontrolled infiltration and windows’ operation, buturban environmental pollution is exacerbating allergies and respiratory conditions among the youthpopulation. In this way, this exposure has a significant effect on both the academic performanceand the general health of the users. Thus, the analysis of the occupants’ noticed symptoms and their perception of the indoor environment is identified as a potential complementary tool to a more comprehensive indoor comfort assessment. The research presents an analysis based on environmentalsensation votes, perception, and indoor-related symptoms described by students during lessons contrasted with physical and measured parameters and operational scenarios. This methodology is applied to 47 case studies in naturally ventilated classrooms in southern Europe. The main conclusionsare related to the direct influence of windows’ operation on symptoms like tiredness, as well asthe low impact of CO2 concentration variance on symptomatology because they usually exceeded recommended levels. In addition, this work found a relationship between symptoms under study with temperature values and the environmental perception votes, and the special impact of the lack of suitable ventilation and air purifier systems together with the inadequacy of current thermal systems

A comprehensive assessment of indoor environmental conditions is performed on a representative sample of classrooms in schools across southern Spain (Mediterranean climate) to evaluate the thermal comfort level, thermal perception and preference, and the relationship with HVAC systems, with a comparison of seasons and personal clothing. Almost fifty classrooms were studied and around one thousand pool-surveys distributed among their occupants, aged 12 to 17. These measurements were performed during spring, autumn, and winter, considered the most representative periods of use for schools. A new proposed protocol has been developed for the collection and subsequent analysis of data, applying thermal comfort indicators and using the most frequent predictive models, rational (RTC) and adaptive (ATC), for comparison. Cooling is not provided in any of the rooms and natural ventilation is found in most of the spaces during midseasons. Despite the existence of a general heating service in almost all classrooms in the cold period, the use of mechanical ventilation is limited. Heating did not usually provide standard set-point temperatures. However, this did not lead to widespread complaints, as occupants perceive the thermal environment as neutral—varying greatly between users—and show a preference for slightly colder environments. Comparison of these thermal comfort votes and the thermal comfort indicators used showed a better fit of thermal preference over thermal sensation and more reliable results when using regional ATC indicators than the ASHRAE adaptive model. This highlights the significance of inhabitants’ actual thermal perception. These findings provide useful insight for a more accurate design of this type of building, as well as a suitable tool for the improvement of existing spaces, improving the conditions for both comfort and wellbeing in these spaces, as well as providing a better fit of energy use for actual comfort conditions.

In southern Europe, the present stock of social housing is ventilated naturally, with practice varying in the di erent seasons of the year. In winter, windows are kept closed most of the day with the exception of short periods for ventilation, whereas the rest of the year the windows are almost permanently open. In cold weather, air changes depend primarily on the air infiltrating across the envelope and when the temperature is warm, on the air flowing in through open windows. CO2, PM2.5, and TVOC concentration patterns were gathered over a year’s time in three social housing developments in southern Europe with di erent airtightness conditions and analyzed to determine possible relationships between environmental parameters and occupants’ use profiles. Correlations were found between TVOC and CO2 concentrations, for human activity was identified as the primary source of indoor contaminants: peak TVOC concentrations were related to specific household activities such as cooking or leisure. Indoor and outdoor PM2.5 concentrations were likewise observed to be correlated, although not linearly due to the presence of indoor sources. Ventilation as presently practiced in winter appears to be insufficient to dilute indoor contaminants in all three buildings, nor does summertime behavior guarantee air quality.

A large part of the school building stock in Andalusia lacks ventilation facilities, so that the air renewal of the classrooms is achieved through the building envelope (air infiltration) or the opening of windows. This research analyses the airtightness of the classrooms in Andalusia and the evolution of CO2 concentration during school hours through in situ monitoring. Pressurization and depressurization tests were performed in 42 classrooms and CO2 concentration was measured in two di erent periods, winter and midseason, to study the impact of the di erent levels of aperture of windows. About 917 students (11–17 years of age) were surveyed on symptoms and e ects on their health. The mean n50 values are about 7 h-1, whereas the average CO2 concentration values are about 1878 ppm, with 42% of the case studies displaying concentrations above 2000 ppm with windows closed.

Social housing dating from the postwar years through the end of the twentieth century is one of the major stores of European cities’ residential stock. As it is generally characterised by a poor thermal performance and an ine cient control of energy consumption, it constitutes one of the main targets for residential heritage renewal. This study aimed to locate and quantify air leaks across building envelopes in Mediterranean multifamily housing with a view to curbing the uncontrolled inflow of outdoor air that has a direct impact on occupant comfort and housing energy demand. Airtightness tests conducted in a series of protocols to quantify draught across envelope elements were supplemented with qualitative infrared thermographic and smoke tests to locate leakage pathways. Air was found to flow mainly across façade enclosures, primarily around openings, as well as through service penetrations in walls between flats and communal areas accommodating electrical and telecommunication wires and water supply, domestic hot water (DHW), and drainage pipes. The general absence of evidence of draught across structural floors or inter-flat partitions was consistent with the construction systems in place.

Although energy analysis techniques can contribute to substantial energy savings in housing stock retrofitting operations, the outcomes often deviate significantly from the predicted results, which tend to overestimate potential savings by overestimating the starting energy baselines, particularly in southern Europe. This deviation can be largely attributed to occupant practice relating to the use of air conditioning facilities and the temperatures at which occupants feel comfortable. The patterns observed differed widely from standard values. In this study environmental variables, primarily indoor air temperature both with and without HVAC, were monitored in occupied dwellings for a full year. The data gathered were supplemented with surveys on occupants’ temperature-related behaviour to define comfort patterns. The findings show that the standards in place are not consistent with actual comfort-accepted patterns in medium- to low-income housing in southern Spain, where energy consumption was observed to be lower than expected, mostly because occupants endure unsuitable, even unhealthy, conditions over long periods of time. A new user profile, better adjusted to practice in southern Europe, particularly in social housing, is proposed to reflect the current situation.

Daylight performance metrics provide a promising approach for the design and optimization of lighting strategies in buildings and their management. Smart controls for electric lighting can reduce power consumption and promote visual comfort using different control strategies, based on affordable technologies and low building impact. The aim of this research is to assess the energy efficiency of these smart controls by means of dynamic daylight performance metrics, to determine suitable solutions based on the geometry of the architecture and the weather conditions. The analysis considers different room dimensions, with variable window size and two mean surface reflectance values. DaySim 3.1 lighting software provides the simulations for the study, determining the necessary quantification of dynamic metrics to evaluate the usefulness of the proposed smart controls and their impact on energy efficiency. The validation of dynamic metrics is carried out by monitoring a mesh of illuminance-meters in test cells throughout one year. The results showed that, for most rooms more than 3.00 m deep, smart controls achieve worthwhile energy savings and a low payback period, regardless of weather conditions and for worst-case situations. It is also concluded that dimming systems provide a higher net present value and allow the use of smaller window size than other control solutions.

Energy retrofitting of the housing stock is a priority in current regulatory standards as a means of reducing energy consumption. The strategies used in retrofitting housing stock ought to respond both to regulatory conditions and to two challenges: specific climate conditions and the improvement of comfort conditions. These issues are especially important in the warmer regions of the Mediterranean, and will be even more so in the future due to climate change. The aimof this paper is to assess the influence that the improvement of facade insulation and the use of ventilation have on the existing housing stock. To do so, an energy evaluation is conducted using on-site monitoring of free-running conditions in test cells reproducing a residential room, both in current condition and with the retrofitted proposal, in Seville (Spain). The results obtained show limited improvement of the facade insulation when outdoor temperatures are high, as well as the influence of ventilation, mainly nocturnal, depending on the ventilation rate and the minimum outdoor temperatures.

Daylight performance metrics provide a promising approach for the design and optimization of lighting strategies in buildings and their management. Smart controls for electric lighting can reduce power consumption and promote visual comfort using different control strategies, based on affordable technologies and low building impact. The aim of this research is to assess the energy efficiency of these smart controls by means of dynamic daylight performance metrics, to determine suitable solutions based on the geometry of the architecture and the weather conditions. The analysis considers different room dimensions, with variable window size and two mean surface reflectance values. DaySim 3.1 lighting software provides the simulations for the study, determining the necessary quantification of dynamic metrics to evaluate the usefulness of the proposed smart controls and their impact on energy efficiency. The validation of dynamic metrics is carried out by monitoring a mesh of illuminance-meters in test cells throughout one year. The results showed that, for most rooms more than 3.00 m deep, smart controls achieve worthwhile energy savings and a low payback period, regardless of weather conditions and for worst-case situations. It is also concluded that dimming systems provide a higher net present value and allow the use of smaller window size than other control solutions

It is known that glazed openings are very important elements in the energetic behavior of buildings, especially in Mediterranean climates where there are many hours of solar radiation. The objective of this study was to determine the influence of solar protection on the energy demand of public housing structures in these climates. To this end, the reduction in energy demand achieved by fixed solar protectors in combination with mobile protectors (blinds) was quantified, including an evaluation of the influence of their geometry, dimensions, degree of openness, and the orientation of the opening. To analyze and quantify energetic demand, a block of public housing units in a neighborhood of Seville (latitude 37°23' N) was used as a model. This block is typical of public housing in the Mediterranean region. Simulated energetic models were created using DesignBuilder, achieving reductions in the annual energy demand from 10% to 27% according to the orientation chosen. The results and conclusions of the study are applicable to new construction, energetic rehabilitation projects, and/or the improvement of existing buildings