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In hospitals, operating rooms are energy-intensive spaces, due to the high flow of outside air required to achieve the necessary indoor air quality. Operating rooms demand ventilation continuously, despite periods of low daily surgical activity. However, by controlling ventilation during inactive periods in the operating room, significant energy savings can be achieved, avoiding penalties on IAQ levels. This paper evaluates the energy savings achieved by introducing ventilation flow control and regulation systems in operating rooms of hospitals located in different climatic zones within Spain. In addition, emissions and economic savings have also been evaluated. Two control and regulation strategies of the air flow to be supplied and extracted in the operating rooms, during periods of inactivity, are studied and include regulation by schedule and regulation by occupancy. Data from a 900-bed university hospital center are used as a reference to evaluate the average occupancy of the operating rooms, and the energy consumption, thus validating the model for calculating the demand of a typical operating room. The energy savings for the regulation by occupancy are 37.5%, and the regulation by schedule are 40% of the annual demand, with respect to an operating room working permanently. [ABSTRACT FROM AUTHOR]

The use of green roofs entails environmental, economic and social benefits as sustainable tools of architecture. They present proven benefits in the path towards carbon neutrality and the reduction of the consumption of energy resources, especially in the field of renovation and improvement of the thermal envelope. In Spain, the current climate crisis also implies a problem of water stress, so it is necessary to analyse in more detail the behaviour of self-sustaining green roofs in the different climatic and rainfall zones into which the territory is divided. Evapotranspiration is the main mechanism of heat dissipation in green roofs, but in this study, it is observed that in the case of self-sustaining roofs with limited water content, the greatest losses through evapotranspiration occur in climates with high temperatures and solar radiation, above cities with higher rainfall and colder climates. On the contrary, the greatest energy savings are obtained in this type of cold climate. Evapotranspiration in self-sustaining roofs is not the most determining factor for achieving energy savings. The design of the roof, the geometry and orientation of the building, as well as the cooling energy consumption, play a more determining role. [ABSTRACT FROM AUTHOR]

Hospitals are highly energy-demanding buildings, where simple actuations can involve large savings. However, energy efficiency actions must comply with the high safety standards. Operating rooms demand continuous ventilation despite the short activity periods. Setback during non-occupation of the operating rooms can reduce ventilation loads but must not hinder indoor overpressure to avoid infiltrations. Besides, it prevents any existing heat recovery system from operation. This work evaluates setback ventilation in operating rooms at a case study in Spain, from two approaches: its effect on indoor overpressure and its preference to an existing coil heat recovery (runaround) loop. It based on monitored data of two operating rooms under setback and normal ventilation with operation of the heat recovery system. Seven tests are performed throughout the year, whose comparison to estimated results enables extrapolation to yearly operation. Results show that indoor overpressure maintains at 15 Pa under setback, thus meeting current and coming standards. Setback turned to be always preferable to hear recovery under cooling needs. Estimated heating and electric yearly supply energy savings reach 29 MWht and 262 MWhe, the latter accounting for 2% of the total electric energy consumption of the hospital during 2019. [ABSTRACT FROM AUTHOR]

In Spain, the regulation of energy savings in buildings has evolved in parallel with the Energy Performance of Buildings Directive (EPBD). With the upcoming Basic Document on Energy Saving of the Technical Building Code (CTE-DB-HE 2018), nearly zero-energy buildings (NZEBs) are addressed for the first time, including both new buildings and renovated buildings. The goal of the present work is to present the innovations of the forthcoming modifications introduced by the implementation of the EPBD 2010 in Spain, highlighting the energy rehabilitation possibilities offered, with a goal of achieving the classification of all buildings as NZEBs by 2020. To illustrate these modifications, a complete case study is analyzed, in which the improvements introduced with respect to the previous regulation are checked against the new renewable energy contribution requirements for the production of domestic hot water, energy demand limits and energy consumption limits of the upcoming CTE-DB-HE 2018. In this way, we clarify how the energy consumption of the residential building stock is expected to be reduced and how policies that favor building energy rehabilitation can be encouraged to achieve the European goals for 2020 and 2030. • The new energy saving requirements of building are analyzed. • The main changes introduced are illustrated using a case study. • Indicators to evaluate the residential sector buildings are compared. • This work is useful for drafting energy rehabilitation scenarios. [ABSTRACT FROM AUTHOR]

The study of the thermal comfort of the occupants of a building represents an important challenge, due to its close relation with energy efficiency. Facing the application of set-point temperatures, the adaptive comfort model proposes the linking of the comfort temperature to the outdoor temperature which would potentially reduce the use of the HVAC system. Although there are studies that propose experimental adaptive models, few verify their effectiveness. In the current study an adaptive comfort algorithm for hybrid buildings is experimentally validated based on a 17-month field study in office buildings in Spain. The implementation of the algorithm in the HVAC control system, both during the cooling and the heating period, allowed for the evaluation of the energy consumption, obtaining savings of 27.5% and 11.4% respectively. The percentage of thermal sensation votes in comfort evolved from 94% (prior to implementing the comfort algorithm) to 87.5% (once implemented) for the summer season and from 79.5% to 81.6% for the winter season. The results demonstrate that the adaptive model is effective for the optimization of HVAC systems, and that it is possible to achieve energy savings without impairing the comfort of its occupants for the type of climate and buildings considered. [ABSTRACT FROM AUTHOR]

The new Basic Document on Energy Saving of the Technical Building Code (CTE-DB-HE) provides the necessary requirements to achieve nearly zero-energy buildings (NZEBs) and promotes the use of renewable energies in the Spanish building sector. In addition, the new CTE-DB-HE, transposition of the Energy Performance of Buildings Directive 2018, introduces specific requirements for the implementation of electric vehicle charging infrastructures in building car parks. The objective of this study is to analyse the energy and environmental impacts of the application of the new CTE-DB-HE in the residential sector. Different multi-family buildings in the most representative cities that meet the requirements for new and renovated buildings and use different heating and domestic hot water systems, as well as photovoltaic solar systems, are studied. The results are compared with those obtained by applying the previous regulations. Compared to the previous NZEBs, the new NZEBs achieve reductions by at least 46% in non-renewable primary energy consumption and 13% in total primary energy consumption. In addition, the changes introduced are shown to have helped prompt significant progress in the achievement of a highly energy-efficient and decarbonized building stock, achieving a reduction by at least 19% by 2050 in the main energy and environmental indicators. • The implementation of the EPBD 2018 in the Spanish residential sector is analysed in detail. • The main novelties introduced by the CTE-DB-HE 2022 are studied. • The evolution of the main indicators to evaluate energy-saving requirements in the residential sector is studied. • The impact achieved with respect to previous regulations is evaluated. • The impact achieved for the future residential sector in 2030 and 2050 is evaluated. [ABSTRACT FROM AUTHOR]

The residential sector in the European Union accounts for 27% of final energy consumption and 23% of CO 2 emissions. Due to this situation, the European Union, in order to strive for greater energy efficiency and savings, has established the Energy Performance of Buildings Directive, which, in the case of Spain, takes the form of a Basic Document outlining Energy Saving in the Technical Building Code (CTE-DB-HE). The aim is to perform an energy and environmental analysis in a multi-family housing block, evaluating improvements that are the result of the implementation of the CTE-DB-HE and comparing them with the previous situation. For this purpose, five representative cases for 26 Spanish cities located in cold climate zones are analyzed. The results reveal that with the current rules, an energy demand reduction of over 60% is achieved. In addition, 65% higher reductions are obtained both in the non-renewable primary energy consumption and CO 2 emissions, thereby achieving class B building status. These remarkable savings show that the right direction is being taken toward nearly zero-energy buildings (NZEBs). [ABSTRACT FROM AUTHOR]

The changes in Spanish legislation on energy efficiency seek to set the basis for achieving European energy and climate goals, especially insofar as decreasing primary energy consumption and reducing CO 2 emissions. This has led to positive changes in energy in the building sector from traditional construction methods which did not consider energy efficiency (e.g., did not include envelope insulation). This study analyzed 342 residential buildings built from 1981 to 2015 and characterized their parameters (areas, orientation, number of stories, etc.), envelopes, domestic hot water, and heating and air-conditioning systems. Based on this characterization, a model single-family dwelling and another model multifamily dwelling were designed to evaluate their energy efficiency as a function of changes in construction and their cost in southeast Spain. The main results were that recently built buildings (built after 2006) have included domestic hot water from solar sources, insulating materials in their envelopes and have considerably improved construction systems, due to the requirements of current legislation. Fruit of these improvements is a drop in CO 2 emissions of up to 82%, according to calculations done with official programmes. From an economic perspective, these changes have raised construction costs by 11% in multifamily dwellings and 17% in single-family dwellings. [ABSTRACT FROM AUTHOR]

In many pressurized irrigation water distribution networks, rising energy costs are having a significant impact on system performance, environmental impact and the profitability of agribusinesses and farms dependant on water supplies for irrigated production. In this study, a new methodology is proposed for analysing the location of critical control points (hydrants) to reduce energy consumption. The methodology is developed and applied using two irrigation districts located in Southern Spain (Fuente Palmera and El Villar). The new approaches provide a framework for comparing different energy saving strategies, including improved critical point management and network sectoring. The results show that potential energy savings of around 10% and 30% are possible in each district when the theoretical irrigation requirements are modeled. However these savings reduce to 5% and 12% when the local farmers' practices of deficit irrigation are incorporated. These results are compared to those obtained for networks sectoring in the same irrigation networks in a previous work. The study confirms that that a sectoring approach works best for reducing the energy costs associated with meeting actual irrigation water demands in irrigation districts where energy consumption is a limiting factor on production. [ABSTRACT FROM AUTHOR]

Abstract: The proper estimation of the energy content of the residual fraction from mechanical–biological treatment (MBT) plants is essential for planning and promoting different methods to decrease its environmental impact, to lower the consumption of energy resources, and to reduce economic costs. Currently, in many countries, the residual fraction from these plants is disposed of in a landfill with few recovery actions. This paper proposes a methodology for estimating the energy content of the aforementioned fraction. To validate it, the methodology is applied to a MBT plant in Zaragoza that collects residual household waste from municipal solid waste (MSW) from 62 municipalities in four regions of Aragon – Zaragoza, Ribera Baja del Ebro, Campo de Cariñena, and Campo de Belchite. From the methodology, an energy potential of 17929.24kJ/kg of the residual fraction from this MBT plant is estimated, which is equivalent to 100.18ktoe per year. [Copyright &y& Elsevier]

Abstract: A Window Energy Rating System (WERS) provides a simple, approximate method to compare the energy performance of the various windows and to determine the different potential savings for the various weather conditions. The main aim of this paper is to obtain a WERS for two climatic zones in Spain. For this purpose, the heating loads and energy savings of a residential building with different types of windows were obtained by three ways. Firstly, the energy through the window was evaluated considering only the climatic conditions. Secondly, the study was performed taking into account the energy useful for the heating system considering the climate and the type of building. Finally, the different cases were simulated using TRNSYS16 and WINDOW5. This study was performed for different European climates. The WERS proposed here is based on the second method. It takes into account the U factor of the window, U factor of the frame, absortivity of the frame, solar heat gain of the glazing and infiltration. [Copyright &y& Elsevier]

Abstract: This paper studies a new innovative concrete with phase change materials (PCM) on thermal aspects. The final objective is to develop a product which would achieve important energy savings in buildings. The work here presented is the construction and experimental installation of two real size concrete cubicles to study the effect of the inclusion of a PCM with a melting point of 26°C. The cubicles were constructed in the locality of Puigverd of Lleida (Spain). The results of this study show the energy storage in the walls by encapsulating PCMs and the comparison with conventional concrete without PCMs leading to an improved thermal inertia as well as lower inner temperatures. [Copyright &y& Elsevier]

A regulating reservoir between the water supply source and the delivery system buffers the system from fluctuating demands. In addition, the system can reduce energy costs, by storing water pumped during off-peak energy tariff times and by improving the operation of pumping stations. A model is proposed to determine a regulating reservoir's capacity and establish an annual pumping schedule that accounts for energy costs. The optimal reservoir size and operation minimize the sum of the amortized reservoir construction and annual pumping costs (annual total cost). The solution was determined using a dichotomic searching procedure that includes one algorithm to calculate the optimal reservoir dimensions using Newton's method and another algorithm to determine the optimal annual pumping to the reservoir based on the concept of ‘emptying period’. The model was applied to a pressurized irrigation delivery system located in southern Spain. The analysis used historical hourly water demand data. A cluster analysis was used to screen non-typical demand data from the data set before extracting a typical temporal demand pattern. The analysis indicated that the addition of a regulating reservoir with optimal size and operation scheme was cost effective. Total costs can be further reduced by adjusting the demand pattern to better match with off-peak energy tariff times. [ABSTRACT FROM AUTHOR]

Olive oil solid residue, "orujo", results from the extraction of olive oil through physical processes. With a variable composition, it is mainly used as a raw material to extract the residual oil that remains in the solid cake, prior to drying. The resulting solid is called "orujillo", and has been mainly used as a solid fuel. Its use as a solid fuel presents some problems due to the changes in olive oil production methods which have resulted in lower quality residual olive oils and byproducts. This paper presents the advantages and disadvantages of the current systems, in an attempt to solve those problems. Furthermore, this research presents new solutions compared to the existing ones from economic and environmental points of view. All these solutions are set within the socio-economic framework of the province of Jaén, in Spain. [ABSTRACT FROM AUTHOR]

In Europe, buildings are responsible for more than one third of the total final energy demands and greenhouse gas emissions. In the last twenty years, the European Union has published a succession of energy performance of building directives to define and ensure the fulfilment of a series of objectives regarding greenhouse gas emissions, energy consumption, energy efficiency and energy generation from renewable sources in buildings. For its part, Spain is adapting its legal framework, transposing these directives with the aim of achieving greater energy efficiency and sustainability for buildings. Under this context, an energy, economic and environmental assessment is performed to analyze the impact of these regulatory changes on a single-family home including a photovoltaic installation for self-consumption with surpluses and/or a solar thermal installation for domestic hot water supply, located in each one of the eight thousand one hundred thirty-one municipalities that make up Spain. The energy behavior of the original house is compared with that obtained after it is updated with these new facilities. The transient system simulation tool is used for the energy study. The results show that the European objectives are far exceeded. The energy savings achieved range from 67% to 126%, carbon dioxide emissions decrease by 42% to 100% and energy bills are reduced in cost by 32% to 81%. The findings of this work can be used by policymakers as guidelines for the development of national strategic plans and financial incentives for the promotion of small-scale residential photovoltaic and solar thermal applications, as well as by designers, supervisors, managers and developers to include them in their projects. [ABSTRACT FROM AUTHOR]