Energy Intervention in the residential sector in the south of Spain: Current challenges

Informes de la Construcción Vol. 65, 532, 457-464, octubre-diciembre 2013 ISSN: 0020-0883 eISSN: 1988-3234 doi: 10.3989/ic.13.074 SUMMARY It can be estimated that approximately half of energy consumption in Spanish residential buildings derives from heating and air conditioning systems. It is therefore advisable to invest in retrofitting projects to reduce energy demand. However, although as a rule energy interventions are expected to bring about significant potential energy savings, it should be noted that this is often not so straightforward, particularly in southern Spain, where there are significant deviations from the expected energy scenario. Recent research shows that in many cases there is no direct relationship between energy demand and real energy use, and the low energy rate is combined with deficiencies in comfort conditions. In order to ensure the real cost-efficiency of the actions is essential, further research for defining these behaviours. The European EnergyTIC project is a continuation of the work already carried out in this context by the EFFICACIA and AMEC research projects. 113-98 RESUMEN En los edificios de viviendas españoles podemos estimar que la mitad del consumo energético se debe a los sistemas de calefacción y refrigeración. En general, resulta aconsejable invertir en proyectos de rehabilitación para limitar su demanda energética, sin embargo, aunque las intervenciones energéticas puedan suponer un significativo potencial de ahorro de energía, habría que manifestar que en muchas situaciones, especialmente en el área sur, no siempre será así, con desviaciones importantes de los comportamientos energéticos esperados. Investigaciones recientes sobre edificios de viviendas protegidas en el Sur de España señalan que no existe habitualmente una relación directa entre demanda de energía y uso real de la misma, asociado el bajo consumo a una carencia de prestaciones de confort. Para rentabilizar las actuaciones es fundamental profundizar en investigación y caracterización de estos comportamientos. En este contexto, se han desarrollado los proyectos de EFFICACIA, AMEC y el proyecto europeo EnergyTIC. (*) Inst. Universitario de Arquitectura y Cs. de la Construcción - Universidad de Sevilla (España). Persona de contacto/Corresponding author: [email protected] (J.J. Sendra) Energy intervention in the residential sector in the south of Spain: Current challenges Intervención energética en el sector residencial del sur de España: Retos actuales J.J. Sendra(*), S. Domínguez-Amarillo(*), P. Bustamante(*), A.L. León(*) Keywords: Energy efficiency; energy retrofitting; monitoring; low energy buildings; residential sector. Palabras clave: Eficiencia energética; rehabilitación energética; monitorización; “low energy”; sector residencial. Recibido/Received: 06 jun 2013 Aceptado/Accepted: 27 jul 2013 458 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 J.J. Sendra, S. Domínguez-Amarillo, P. Bustamante, A.L. León 1. INTRODUCTION The different analyses of national energy consumption show the prominent role of the residential building sector, which in 2010 accounted for 17% of final energy and up to 25% of electric energy demand, with indications that this would increase in the next few years (1). Bearing in mind these figures the public administration is concentrating on energy savings in this sector in order to reach European goals for a 50-85% reduction of CO2 emissions by 2050 (2). For 2020 the National Energy Plan predicts that 15.6% of the overall reduction in energy savings will be accounted for by the construction sector (3). It should be noted that in Spanish residential buildings approximately half of this consumption is due to heating systems (around 47% of the total) and cooling systems (around 0.8%), with cooling increasing slightly in the Mediterranean area, albeit with a greater effect on primary energy, as the source of energy is mainly electric (1). Although energy saving measures tend to concentrate on the tertiary sector given the more intense specific uses, the residential sector is responsible for the highest consumption within the construction sector: 14676 ktep of final energy compared to the 9540 ktep consumed in the tertiary sector in 2011 (4). These data indicate the advisability of energy retrofitting of the existing residential building stock and forecast significant reductions in the energy consumption of retrofitted buildings, which should be taken into account when drawing up intervention policies, assigning resources (subsidies, public grant schemes), and encouraging energy service companies (ES- COs) to enter into the construction sector. These considerations and more optimistic scenarios are used as basic tools for energy behaviour evaluation and energy saving prediction. The present implementation of the procedure for the energy qualification of existing buildings (5) is expected to highlight the difference between the energy consumption of new and existing retrofitted buildings (6). On a national scale, all the procedures for energy assessment derived from Directive 2002/91/CEE and its revisions (7) (8) are based on a general energy efficiency calculation methodology (limitation of energy demand and energy qualification of new and existing buildings), and predictions for intensity and patterns of use of the building, but these patterns are not always achieved. However, our research team’s field studies on the energy behaviour of these residential buildings shed doubt on whether these calculations for reducing energy consumption are realistic, as in many cases there is a significant discrepancy between theoretical demand and the actual consumption of users. Factors such as the decision not to maintain comfort conditions in the housing units during the more extreme months (the users show significant tolerance to the deviations from the comfort conditions band), the absence of thermal conditioning equipment for the entire housing area, or users spending less time within the housing units (few hours of use or even partial use of the house space) generate energy consumption below that expected in the current models used for energy assessment and qualification of residences. In addition to these factors, the appearance of regional differences and the income level of users (9) (10) must be taken into account. Research carried out on the actual energy consumption of social housing located in the south of Spain shows values below the averages stated as a reference for Energy Qualification (11). As a result, investments in the retrofitting of this type of building by modifying the envelope, usually façades and openings, do not tend to be effective or cost efficient. Equally, many of the operations to incorporate renewable energies into existing residential buildings may be less efficient than expected (12) (9). All this makes it imperative to carry out a precise assessment of each individual intervention, prior to decision making. This article aims to reflect upon the specific qualities of residential buildings in the south of Spain, particularly subsidised housing, and to emphasise the need for further research into these behaviours in order to implement efficient cost-effective intervention policies and energy actions. To this end several research projects developed and carried out on social housing by members of the research group Arquitectura, Patrimonio y Sostenibilidad: Acústica, Iluminación y Energía, TEP-130, of the Andalusian Plan for Research, Development and Innovation, are presented: -R&D&i EFFICACIA and AMEC projects: continuous monitoring of environmental variables and use of energy, as well as the assessment of strategic energy intervention proposals for the retrofitting of social housing and the design of new buildings. -R&D&i EnergyTIC project (ICT PSP 2010 programme of the European Commission): supervision of the use of electricity and water, with information feedback for users, including auditing and economic assessment of intervention solutions for neighbourhoods and buildings. 1st PRIZE -Journal Informes de la ConstruCCIónfor the best paper of the “I International and III National Congress on Sustainable Construction & Eco-Eefficient Solutions”. Seville, Spain. May 20, 2013. 459 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 Energy intervention in the residential sector in the south of Spain: Current challenges Intervención energética en el sector residencial del sur de España: Retos actuales 2. RESEARCH, SCOPE AND CASE STUDY Between 2007 and 2011, temperature conditions were monitored and main energy consumption was assessed on a set of 218 social housing units in Seville. This was part of two research projects: EFFICACIA (2007-2009), financed by the Andalusian Technological Corporation to reduce demand and encourage energy saving in the construction of housing in Andalusia (9), and AMEC (2009- 2011), which is considered its continuation. The building chosen as case study for both projects is a social multi-family residential building, Cross-Pirotecnia (Figure 1), a block of 218 housing units built around a central courtyard (Figure 2) in the “Pirotecnia” area in the south of Seville. This building was constructed by EMVISESA in 2005 as part of the Municipal Housing Plan of Seville Town Council, following the regulations in place prior to the implementation of the Technical Building Code. The building envelope presents standard values similar to those stipulated in the current regulations (although the building's construction predates these), and is a typical example of the construction methods of the time. The methodology for the research consisted of specific tasks, which included establishing the energy demand and consumption in real time of these subsidised leased housing units, monitoring them and establishing the consumption habits of residents. The results, analyses and conclusions of these tasks were described in León et al. (11) and Sendra et al. (9). 3. MONITORING OF THE HOUSING UNITS The purpose of monitoring was to record and analyse the in situ measurements of the environmental variables and energy consumption over a three-year period (October 2008-November 2011) in a real occupation situation, unlike alternative methods which monitored unoccupied housing units to avoid possible disruptions from users, and subsequently adjusted results applying specific user behaviour protocols. For the eight housing units selected (Figure2) measurements were carried out on environmental variables (temperature, relative humidity, CO2 levels), energy consumption (hot water, heating, air conditioning, electricity), while variables providing information on the conditions of use of buildings (presence detectors and magnetic contacts on windows, etc.) were recorded. This information was used to extrapolate the results to the rest of the housing units. The installation of the monitoring system was carried out in compliance with the protocol stipulated in UNE-EN ISO 7726:2002 (13). The analyses were carried out on a weekly (distinguishing between weekdays and weekends), monthly, seasonal and annual basis. 1. View of the west-facing façade. 2. Housing units monitored. 1 2 15 November December January February March April May June July August September October 17 19 21 23 25 27 29 31 33 N S E W TºC Average summer temp. 29.5 ºC Average winter temp. 17.6 ºC Average annual temp. 23.5 ºC 3 0 200 400 600 800 1000 1200 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00 November May December January February March April June July August September October MAX.winter MAX.summer MIN.spring MIN.autumn Wh 4 3. Average monthly indoor temperatures of the housing units according to orientation. 4. Daily power demand for an annual period by month. 460 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 J.J. Sendra, S. Domínguez-Amarillo, P. Bustamante, A.L. León 3.1. Monitoring indoor temperatures Recording temperatures in the housing units monitored (Figure 3), whatever their orientation, shows how in general there are indoor temperature conditions which are far removed from the comfort band in summer and winter, even when comparing them with the more flexible reference values, and reach very extreme situations for the least favourable orientations (north in winter and west in summer). In winter (the period between November and February) the average indoor temperature in the 8 housing units monitored was 17.6 ºC, lower than what is considered a comfortable temperature. As was to be expected, the minimum values were reached in the two housing units which mainly faced north, since the average temperature measured in this winter period was 17.0 ºC. In contrast, in the summer months (June to September) the average indoor temperature rose to 29.5 ºC, with maximum values recorded in the two west-facing housing units, which reached average temperature values of 30.4 ºC. The thermal jump of average temperatures for the set of housing units between the summer and winter periods is therefore approximately 12 ºC, which greatly exceeds the upper and lower thresholds of the comfort band for these two seasons. The situation in these housing units monitored in Seville could be extrapolated to much of the subsidised housing built in Andalusia. For many hours in the year there is a lack of indoor comfort conditions which users frequently try to resolve in winter by using portable electric heaters, such as the traditional brasero heaters [small heaters placed under covered tables], which are highly inefficient from the point of view of energy. 3.2. Monitoring of consumption This real situation of a lack of indoor comfort in Andalusian social housing for many hours a year leads to buildings with energy consumption that is much lower than what the building envelope would suggest, reaching values typical of Low Energy buildings (14) (Figure 4). This can be seen from the reference values for heating and cooling in Seville as regards energy qualification (Table 1). In mid-season periods, average daily consumption clearly coincides for the minimum values, both in spring and autumn, so it is safe to say that this does not correspond to cooling or heating equipment but is limited to electrical appliances, lighting, computers and standby modes of audiovisual equipment. Through a comparative study, this hypothesis allows us to establish consumption due to heating (winter) and cooling (summer) (Figure 5). These homes lack a communal production system for heating or cooling. Only five of the eight housing units had individual split (heat pump) systems when the monitoring began, and the indoor units were mainly placed in the living rooms, where electric consumption was monitored. In the summer period in the housing units in which cooling consumption was supervised, equipment was only used in the hotter weeks of the month of July when the indoor temperature was close to 30 ºC. Most of the electric consumption was due to the use of portable ventilation devices and was only slightly higher in the early hours of the afternoon when cooling equipment was used. In winter, heating was only produced by systems with low energy efficiency based on the Joule effect, used early in the morning (bedrooms and bathroom) and in the evening (in the living room, mainly braseros). In no case was any noticeable consumption of heat pumps to heat the housing units observed. The unsuitable choice of equipment led to a greater consumption from heating systems, clearly higher than that of cooling equipment (Figure 5). The annual heating consumption in the housing units monitored in terms of final energy was 1435 kWh and 713 kWh respectively, that is to say, in a ratio of almost 2/1. As the housing units monitored have an average useable surface of 58.83 m², we can calculate this heating and cooling consumption per surface unit and after applying conversion factors, express it in terms of 5. Average yearly power demand. 0 100 200 300 400 500 600 April May June July August September October November December January February March 226 Wh 421 Wh 507 Wh 251 Wh Wh Cooling Heating Functional consumption Location Heating demand kWh/m² Cooling demand kWh/m² HWS demand kWh/m² Heating emission kgCO2/m² Cooling emission kgCO2/m² Heating primary E. consumption kWh/m² Cooling primary E. consumption kWh/m² Seville 16.6 23.4 12.3 5.3 5.9 24.1 23.9 Table 1. Reference values for heating and cooling as regards demand in housing unit blocks (19) 5 461 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 Energy intervention in the residential sector in the south of Spain: Current challenges Intervención energética en el sector residencial del sur de España: Retos actuales primary energy, comparing it with the reference values established for the final energy qualification procedure in Seville (Table 1). In the heating period, a monitored primary energy consumption of 24.70 kWh/m² is observed, very close to the 24.10 kWh/m² of the reference value, a clear result of the energy inefficiency of typical heating devices, portable electric heaters, as this consumption is associated with a noticeable deviation from the comfort band of indoor temperature in winter. However, the primary energy consumption for cooling monitored with equipment in five of the eight most energy efficient housing units was 12.12 kWh/m², practically half of the reference value 23.90 kWh/m². This was also partly due to the major deviations of the average summer temperature from the comfort band. Therefore, the potential for saving is much lower than that estimated for these types of buildings. In many cases it can be observed that there is no direct relationship between energy demand and actual energy use, so that there is less scope for reducing the actual consumption in these buildings compared with that calculated. Users are also unaware of the importance of the problem. This significantly lengthens the payback periods for energy interventions, many of which therefore effectively increase energy consumption in relation to the initial situation (even after the improvement of facilities). In order to assess all this, the monitoring study was completed with a series of user questionnaires on occupation and consumption habits. 4. USER SURVEYS ON OCCUPATION AND CONSUMPTION HABITS In order to establish correlations between energy consumption and behaviour patterns the monitoring installation was complemented with a series of surveys (67 in total) on the consumption habits of the tenants of the housing units studied. Two types of surveys were drawn up: winter and summer. These surveys examined aspects such as the size of the family unit, average daily occupation by inhabitant, type of use of the housing units and the hours of use of all sorts of domestic equipment, including heating/cooling. Figure 6 shows the results of the average daily occupation on weekdays compared with the LIDER program protocol. Using the data obtained through monitoring and surveys it was observed that the occupation patterns of the housing units presented a high variability index, far from the use patterns set for the reference software (LIDER and CALENER) (6). The results of the surveys reflected that the habitual use of heating in the winter (Figure7) and cooling in the summer (Figure 8) was limited and was barely dependent on the housing unit use pattern, given that the differences in these habits on weekdays and weekends were not very significant. This reduced use of heating and cooling does not correspond to the indoor environmental conditions close to the comfort conditions for these two extreme periods, as stated in 3.1 (Figure 3). As was to be expected, both on weekdays and weekends the time slot with most use of heating was between 19 h and 23 h, while that of most use for cooling was between 15h and 18 h, in keeping with the consumption readings for these two periods. 6. Daily average occupation in winter and summer. Weekdays (Monday to Friday). 7. Heating use habits. 8. Cooling use habits. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 7H 8H 9H 10H 11H 12H 13H 14H 15H 16H 17H 18H 19H 20H 21H 22H 23H 24H 1H 2H 3H 4H 5H 6H LIDER WEEKDAY PROTOCOL WINTER WEEKDAY HOUSING UNITSUMMER WEEKDAY HOUSING UNIT 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 7H 8H 9H 10H 11H 12H 13H 14H 15H 16H 17H 18H 19H 20H 21H 22H 23H 24H 1H 2H 3H 4H 5H 6H HEATING Weekday HEATING Weekday 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 7H 8H 9H 10H 11H 12H 13H 14H 15H 16H 17H 18H 19H 20H 21H 22H 23H 24H 1H 2H 3H 4H 5H 6H COOLING Weekday COOLING Weekend 6 7 8 462 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 J.J. Sendra, S. Domínguez-Amarillo, P. Bustamante, A.L. León Although there is a correlation between the timetables for consumption of heating and cooling systems indicated in the residents' survey and those observed in the readings of monitored data, the actual consumption was lower than expected since neither the occupation frequency nor the use frequency are a daily constant, particularly in the summer period (especially weekends), when the lower occupation of the housing units affects the lower consumption of the cooling systems, as stated in 3.2. 5. NEW CHALLENGES AND METHODS OR KNOWLEDGE OF ENERGY USE AND CONTROL IN SOCIAL OUSING The two R&D&i projects mentioned earlier continue with a third project, EnergyTIC “Technology, Information and Communication services for engaging social housing residents in energy and water efficiency” (15), financed by the European Union and the EnergyTIC consortium. This is currently being developed and is mainly geared towards supervising and teaching energy use in social housing in Andalusia, feeding information back to occupants in order to identify the most efficient saving measures in each situation, and backs the conclusions of previous studies. The EnergyTIC project (Figure 9) is a pilot project for the assessment of the use of ICT (Information and Communication Technologies) tools to provide users with attainable (Figure 10) and easily understandable information that will allow them to modify the habits of use to optimise consumption and make savings by adopting individualised good practices (16). In addition, by compiling and analysing consumption data the aim is to make major progress on the real consumption and use of the housing unit, taking into account the different types of constructions as well as family and social situations, aspects highlighted by Abrahamse et al. as key in the consumption of residential buildings (17). There are additional plans to draw up a proposal for individualised intervention for each building based on these data and energy audits. This pilot project will implement ICT solutions in 700 subsidised housing units in Malaga in southern Spain (Malaga) and 1000 housing units in the north of France, dating from various periods between the 1960s and 1990s. The information on water and electricity consumption will be compiled in real time by the water (EMASA) and electricity (ENDESA) companies using tele-measurement systems (Figure 10), with hourly or multi-hourly profiles. This information will be processed in a common management application and then broadcast in several layers –energy supervisor and user layers– and transmitted via ICT solutions: social networks, SMS, internet access and TDT-Television (Figure 9). This information will be processed to enable common users to improve management and optimise consumption, both through feedback and peer comparison processes (18). The auditing processes (Figure 11) still under development reflect how difficult it is to reach solutions with sufficient optimum cost and energy-economy profitability to justify their execution. This aspect is of particular interest, as following this analysis most of the proposals considered by the administrations in their plans and blueprints for energy retrofitting should be rejected and others developed that are more suited to the particularities of the area and construction typologies. In the initial studies carried out, actions on façades did not in fact result in efficient reduction of cost and energy consumption, and this in turn prompted a rethinking of traditional intervention strategies. 9. Information flow of the EnergyTIC system. 10. EnergyTIC Internet user interface. 9 10 463 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 Energy intervention in the residential sector in the south of Spain: Current challenges Intervención energética en el sector residencial del sur de España: Retos actuales 7. CONCLUSIONS Use and intensity patterns must be adapted specifically to the south of Spain and its socio-economic profiles. It is essential to reduce the gap between these analysis patterns and reality to carry out more precise assessments of the options for intervention and their energy repercussions. The margin of tolerance in the indoor comfort conditions of inhabitants of social housing in the south of Spain is greater than that assumed by general regulations, so that there is less use of heating systems than expected (and only at certain points, not all over the housing unit) and cooling systems. Many of these homes do not yet have overall efficient heating/cooling equipment and their use is highly sporadic. Users of a low socio-economic level do not consider the energy problem a priority given its limited impact on the family economy, and they simply accept environmental conditions that are far from comfortable. Given that the individual study of each case, including the socio-economic characteristics of inhabitants, is crucial, it should be emphasised that it is impossible to develop catalogues of solutions or establish generic interventions. ACKNOWLEDGEMENTS This article is based on the work carried out for the EFFICACIA and AMEC projects, financed by the Andalusian Technological Corporation and EMVISESA and SODINUR S.L., and on the EnergyTIC project, funded by the European Commission, EnergyTIC consortium and Wind Inertia Technologies S.L. The authors wish to express their thanks for the technical and financial support received as well as for invaluable information and collaboration from the companies above. 11. Energy assessment studies for groups of buildings (EnergyTIC). REFERENCES (1) IDAE. (2011). SECH-SPAHOUSEC Project: Analysis of the Energy Consumption in the Spanish Residential Sector. Final Report, Spanish Institute for Energy Diversification and Saving, Madrid. (2) European Commission. (2011). Energy Roadmap 2050. (3) Government of Spain. (2011). Energy Saving and Efficiency Action Plan 2011-2020. Spanish Institute for Energy Diversification and Saving, Madrid. (4) IDAE. (2011), Annual Report on Energy Indicators: Year 2011, Spanish Institute for Energy Diversification and Saving, Madrid. (5) Ministry for the Presidency of the Government of Spain. (2013). Royal Decree 235/2013, of 5 April, approving the basic procedure for the certification of energy efficiency in buildings, Madrid. (6) AICIA - Thermotechnics Group of the Higher School of Industrial Engineers of the University of Seville. (2009). Condiciones de aceptación de Procedimientos alternativos a LIDER y CALENER. Spanish Institute for Energy Diversification and Saving, Madrid. (7) European Parliament and European Council. (2002). Directive 2002/91/CE of 16 December 2002 on energy performance in buildings. (8) European Parliament and European Council. (2013). Directive 2010/31/UE of 19 May 2010 on energy performance in buildings (revised). 11 464 Informes de la Construcción, Vol. 65, 532, 457-464, octubre-diciembre 2013. ISSN: 0020-0883. eISSN: 1988-3234. doi: 10.3989/ic.13.074 J.J. Sendra, S. Domínguez-Amarillo, P. Bustamante, A.L. León (9) Sendra, J.J., Domínguez, S., León, A.L. et al. (2011). Proyecto Efficacia. Optimización Energética en la Vivienda Colectiva. pp.1-140. Publicaciones Universidad de Sevilla. (10) Domínguez, S. (2012). The Spanish Construction Market, an Outlook to residential sector: The importance of the renovation. 6th Daikin Europe KONWAKAI. Barcelona, Spain. (11) León, A.L., Muñoz, S., León, J., Bustamante, P. (2010). Monitorización de variables medioambientales y energéticas en la construcción de viviendas protegidas: Edificio Cross-Pirotecnia en Sevilla. Informes de la Construcción, 62(519): 67-82. doi:10.3989/ ic.09.045. (12) Domínguez, S., Sendra, J.J., León, A.L., Esquivias, P. (2012). Towards Energy Demand Reduction in Social Housing Buildings: Envelope System Optimization Strategies. Energies, 5(7): 2263-2287. (13) AENOR. (2002). UNE-EN ISO 7726:2002. Ergonomics of the thermal environment. Instruments for measuring physical quantities. AENOR, Madrid. (14) Thomsen, K., Wittchen, K., EuroACE. (2008). SBi 2008:07: European national strategies to move towards very low energy or passive buildings, SBi, Statens Byggeforskningsinstitut, Danish Building Research Institute, Aalborg, Denmark. (15) EnergyTIC consortium. (2013). EnergyTIC: Technology, Information and Communication services for engaging social housing residents in energy and water efficiency.[Online].Available: http://ec.europa.eu/information_society/apps/projects/factsheet/index. cfm?project_ref=270947. (16) Wilhite, H., Ling, R. (1995). Measured energy savings from a more informative energy bill. Energy and Buildings, 22(2): 145-155. (17) Abrahamse, W., Steg, L., Vlek, C., Rothengatter, T. (2007). The effect of tailored information, goal setting, and tailored feedback on household energy use, energy-related behaviors, and behavioral antecedents. Journal of Environmental Psychology, 27(4): 265-276. (18) Domínguez, S., Fernandez-Agüera, J., Escandon, R., Domínguez, E. (2013). Methodology of the data processing with ICT solutions for the evaluation of the energy and water savings. Advanced Materials Research, 689: 158-162. doi: 10.4028/www.scientific.net/ AMR.689.158. * * * Informes de la Construcción Manuscrito aceptado 2013 ISSN: 0020-0883 eISSN: 1988-3234 doi: 10.3989/ic.13.074 RESUMEN En los edifi cios de viviendas españoles podemos estimar que la mitad del consumo energético se debe a los sistemas de calefacción y refrigeración. En general, resulta aconsejable invertir en proyectos de rehabilitación para limitar su demanda energética, sin embargo, aunque las intervenciones energéticas puedan suponer un signifi cativo potencial de ahorro de energía, habría que manifestar que en muchas situaciones, especialmente en el área sur, no siempre será así, con desviaciones importantes de los comportamientos energéticos esperados. Investigaciones recientes sobre edifi cios de viviendas protegidas en el Sur de España señalan que no existe habitualmente una relación directa entre demanda de energía y uso real de la misma, asociado el bajo consumo a una carencia de prestaciones de confort. Para rentabilizar las actuaciones es fundamental profundizar en investigación y caracterización de estos comportamientos. En este contexto, se han desarrollado los proyectos de EFFICACIA, AMEC y el proyecto europeo EnergyTIC. 113-98 SUMMARY It can be estimated that approximately half of energy consumption in Spanish residential buildings derives from heating and air conditioning systems. It is therefore advisable to invest in retrofi tting projects to reduce energy demand. However, although as a rule energy interventions are expected to bring about signifi cant potential energy savings, it should be noted that this is often not so straightforward, particularly in southern Spain, where there are signifi cant deviations from the expected energy scenario. Recent research shows that in many cases there is no direct relationship between energy demand and real energy use, and the low energy rate is combined with defi ciencies in comfort conditions. In order to ensure the real cost-effi ciency of the actions is essential, further research for defi ning these behaviours. The European EnergyTIC project is a continuation of the work already carried out in this context by the EFFICACIA and AMEC research projects. (*) Inst. Universitario de Arquitectura y Cs. de la Construcción - Universidad de Sevilla (España). Persona de contacto/Corresponding author: [email protected] (J.J. Sendra) Intervención energética en el sector residencial del sur de España: Retos actuales Energy intervention in the residential sector in the south of Spain: Current challenges J.J. Sendra(*), S. Domínguez-Amarillo(*), P. Bustamante(*), A.L. León(*) Keywords: Energy effi ciency; energy retrofi tting; monitoring; low energy buildings; residential sector. Palabras clave: Efi ciencia energética; rehabilitación energética; monitorización; “low energy”; sector residencial. Recibido/Received: 06 jun 2013 Aceptado/Accepted: 27 jul 2013 TRADUCCIÓN ESPAÑOL 8Informes de la Construcción. Manuscrito aceptado. 2013. eISSN: 1988-3234. doi: 10.3989/ic.13.074 J.J. Sendra, S. Domínguez-Amarillo, P. Bustamante, A.L. León REFERENCIAS (1) IDAE. (2011). Proyecto SECH-SPAHOUSEC: Analisis del Consumo Energético del Sector Residencial en España. Informe Final, Instituto para la Diversifi cación y Ahorro de la Energía. Madrid. (2) European Commission. (2011). Energy Roadmap 2050. (3) Gobierno de España. (2011). Plan de Acción de Ahorro y Efi ciencia Energética 2011-2020. Instituto para la Diversifi cación y Ahorro de la Energía. Madrid. (4) IDAE. (2011). Informe Anual de Indicadores Energéticos: año 2011. Instituto para la Diversifi cación y Ahorro de la Energía, Madrid. (5) Ministerio de Industria, Energía y Turismo y Ministerio de Fomento del Gobierno de España (2013). Real Decreto 235/2013, de 5 de abril, por el que se aprueba el procedimiento básico para la certifi cación de la efi ciencia energética de edifi cios, Madrid. (6) AICIA - Grupo de Termotecnia de la Escuela Superior de Ingenieros Industriales de la Universidad de Sevilla. (2009). Condiciones de aceptación de Procedimientos alternativos a LIDER y CALENER. Instituto para la Diversifi cación y Ahorro de la Energía. Madrid. (7) Parlamento Europeo y Consejo de Europa. (2002). Directiva 2002/91/CE de 16 de diciembre de 2002 relativa a la efi ciencia energética de los edifi cios. (8) Parlamento Europeo y Consejo de Europa. (2013). Directiva 2010/31/UE de 19 de mayo de 2010 relativa a la efi ciencia energética de los edifi cios (refundición). (9) Sendra, J. J., Domínguez, S., León, A. L., et al. (2011). Proyecto Effi cacia. Optimización Energética en la Vivienda Colectiva. pp. 1-140. Publicaciones Universidad de Sevilla. Sevilla. (10) Domínguez, S. (2012). The Spanish Construction Market an Outlook to residential sector: The importance of the renovation. En 6th Daikin Europe KONWAKAI. Barcelona, España. (11) León, A. L., Muñoz, S., León, J., Bustamante, P. (2010). Monitorización de variables medioambientales y energéticas en la construcción de viviendas protegidas: Edifi cio Cross-Pirotecnia en Sevilla. Informes de la Construcción, 62(519): 67-82, doi: 10.3989/ic.09.045. (12) Domínguez, S., Sendra, J. J., León, A. L., Esquivias, P. (2012). Towards Energy Demand Reduction in Social Housing Buildings: Envelope System Optimization Strategies. Energies, 5(7): 2263-2287. (13) AENOR. (2002). Norma UNE-EN ISO 7726:2002. Ergonomía de los ambientes térmicos. Instrumentos de medida de las magnitudes físicas. AENOR. Madrid. (14) Thomsen, K., Wittchen, K., EuroACE. (2008). SBi 2008:07: European national strategies tomove towards very low energy or passive buildings, SBi, Statens Byggeforskningsinstitut, Danish Building Research Institute. Aalborg, Denmark. (15) EnergyTIC consortium. (2013). EnergyTIC: Technology, Information and Communication services for engaging social housing residents in energy and water effi ciency. Disponible on-line en: http:// ec.europa.eu/information_society/apps/projects/factsheet/index.cfm?project_ref=270947. (16) Wilhite, H., Ling, R. (1995). Measured energy savings from a more informative energy bill. Energy and Buildings, 22(2):145-155. (17) Abrahamse, W., Steg, L., Vlek, C., Rothengatter, T. (2007). The effect of tailored information, goal setting, and tailored feedback on household energy use, energy-related behaviors, and behavioral antecedents. Journal of Environmental Psychology, 27(4): 265-276. (18) Domínguez, S., Fernandez-Agüera, J., Escandon, R., Domínguez, E. (2013). Methodology of the data processing with ICT solutions for the evaluation of the energy and water savings. Advanced Materials Research, 689: 58-162, doi:10.4028/www.scientifi c.net/AMR.689.158. * * * El margen de tolerancia en las condiciones interiores de confort de los habitantes de las viviendas sociales de sur de España es mayor que el asumido desde la normativa general, lo que da origen a un menor uso de los equipos de calefacción (o al menos solo usos localizados, no generalizados a toda la vivienda) y de refrigeración. Más allá de que todavía muchas de estas viviendas no están dotadas de equipos efi cientes para calefacción/refrigeración, menos aún de manera global, cuando sí lo están su uso es muy esporádico. Los usuarios de bajo nivel socio económico no perciben el problema energético como una prioridad, dado su poco impacto en las economías familiares, asumiendo condiciones de ambientales muy alejadas del confort. Es fundamental destacar que no es posible el desarrollo de catálogos de soluciones, ni establecer intervenciones genéricas, siendo fundamental el estudio particularizado de cada caso, incluyendo las características socio-económicas de sus habitantes. AGRADECIMIENTOS Esta comunicación está basada en los trabajos realizados para los proyectos EFFICACIA y AMEC, fi nanciados por la Corporación Tecnológica de Andalucía y las empresas EMVISESA y SODINUR S.L., y el proyecto EnergyTIC, fi nanciado por la Comisión Europea y la empresa Wind Inertia Technologies S.L. Los autores desean expresar su agradecimiento por el soporte técnico y fi nanciero, así como la inestimable información y colaboración realizada por las empresas.