• Energy Research

Abstract New policies on energy efficiency in buildings aim to improve our environment. EU requirements on reduced energy demand to achieve Nearly Zero Energy Buildings are of equal importance to pollution and raw-material consumption. Addressing these parameters, building life-cycle analyses are needed, not only to reduce energy consumption, but also to encourage the use of renewable materials. Other priorities are building maintenance and construction material management at the end of the useful life of the building. The use of wooden facades is not very common in Spain. In this study, its energy efficiency is assessed against Spanish Government Regulations, through the Building Technical Code. Hence, this analysis of wooden facades examines their influence on the thermal behavior of the whole building, considering both material properties and structural design, focused on the exterior cladding or protective layer. These structures imply an optimized assembly design together with the application of a protective treatment, depending on its natural durability. “Radiata pine” was selected as one of the most common pine species in the Basque Country, suitable for cladding and grown in sustainable forestry programs. Several commercial simulation tools were used, such as: Therm, Wufi, and DesignBuilder aiming to a full thermal characterization of these particular enclosures, whereas the results obtained were finally validated through an experimental facility.

Abstract New policies on energy efficiency in buildings aim to improve our environment. EU requirements on reduced energy demand to achieve Nearly Zero Energy Buildings are of equal importance to pollution and raw-material consumption. Addressing these parameters, building life-cycle analyses are needed, not only to reduce energy consumption, but also to encourage the use of renewable materials. Other priorities are building maintenance and construction material management at the end of the useful life of the building. The use of wooden facades is not very common in Spain. In this study, its energy efficiency is assessed against Spanish Government Regulations, through the Building Technical Code. Hence, this analysis of wooden facades examines their influence on the thermal behavior of the whole building, considering both material properties and structural design, focused on the exterior cladding or protective layer. These structures imply an optimized assembly design together with the application of a protective treatment, depending on its natural durability. “Radiata pine” was selected as one of the most common pine species in the Basque Country, suitable for cladding and grown in sustainable forestry programs. Several commercial simulation tools were used, such as: Therm, Wufi, and DesignBuilder aiming to a full thermal characterization of these particular enclosures, whereas the results obtained were finally validated through an experimental facility.

Abstract Double-skin perforated sheet facades, are enclosures composed of a perforated metallic sheet, air chamber and glass, is showing an increasing tendency in modern building design. In a previous research, their thermal behavior was addressed, taking into account several physical parameters such as, perforation rates, colors and materials, as well as the influence of wind penetration through a Matlab® model, validated through a fully experimental test campaign, monitoring metallic sheets during 1 year, for different configurations, within a range of 0–35% (perforation rates), black-white (colors) and galvanized steel-aluminum (materials). Here, following this research, first of all, the behavior of such configurations is also fully addressed, through a complete Energyplus® model (design builder), which was validated through the abovementioned Matlab® model and experimental outputs. The relevant contribution shows a new parametric energy assessment taking into account additional variables such as the air-gap and location (according to the different climate zones defined for Spain). Finally, the influence of different enclosures on the cooling, heating and lighting loads (energy consumptions) of the building as a whole was obtained, demonstrating the suitability of the previously optimized configurations in terms of relative energy savings. This leads to set up a new methodology aiming to the optimization of design sustainability based on minimum energy consumption.

Abstract Double-skin perforated sheet facades, are enclosures composed of a perforated metallic sheet, air chamber and glass, is showing an increasing tendency in modern building design. In a previous research, their thermal behavior was addressed, taking into account several physical parameters such as, perforation rates, colors and materials, as well as the influence of wind penetration through a Matlab® model, validated through a fully experimental test campaign, monitoring metallic sheets during 1 year, for different configurations, within a range of 0–35% (perforation rates), black-white (colors) and galvanized steel-aluminum (materials). Here, following this research, first of all, the behavior of such configurations is also fully addressed, through a complete Energyplus® model (design builder), which was validated through the abovementioned Matlab® model and experimental outputs. The relevant contribution shows a new parametric energy assessment taking into account additional variables such as the air-gap and location (according to the different climate zones defined for Spain). Finally, the influence of different enclosures on the cooling, heating and lighting loads (energy consumptions) of the building as a whole was obtained, demonstrating the suitability of the previously optimized configurations in terms of relative energy savings. This leads to set up a new methodology aiming to the optimization of design sustainability based on minimum energy consumption.

Abstract New materials with external shading systems are mainly implemented on building facades to improve energy efficiency, but also to add a distinctive appearance. The double-skin perforated sheet-metal facade, an enclosure composed of sheet metal, air chambers and glass, is an example of this tendency in modern building design. The aim of this research is to study the thermal behavior of the facade taking into account several physical parameters such as, perforation rates, colors and materials, as well as the influence of wind penetration. The study also quantifies the improvements in terms of energy savings that different configurations of these parameters can bring to the building as a whole. First of all, a theoretical model was built in Matlab® based on an energy balance of these types of enclosure. The experimental process for validation purposes consisted of monitoring metallic sheets within a range of 0–35% (perforation rates), black-white (colors) and galvanized steel-aluminum (materials) in a large-scale test campaign. Excellent agreement was achieved between the outputs from the above-mentioned numerical model and the test campaign, sufficient for its validation. The behavior of different configurations will be described in a further paper, addressing their influence on cooling, heating and lighting loads in the building, with an Energyplus® model, which will be also validated with our theoretical model. Finally, additional parameters such as air-space width and location in the various climate zones defined for Spain will be carefully studied, for the optimization of design sustainability.

Abstract New materials with external shading systems are mainly implemented on building facades to improve energy efficiency, but also to add a distinctive appearance. The double-skin perforated sheet-metal facade, an enclosure composed of sheet metal, air chambers and glass, is an example of this tendency in modern building design. The aim of this research is to study the thermal behavior of the facade taking into account several physical parameters such as, perforation rates, colors and materials, as well as the influence of wind penetration. The study also quantifies the improvements in terms of energy savings that different configurations of these parameters can bring to the building as a whole. First of all, a theoretical model was built in Matlab® based on an energy balance of these types of enclosure. The experimental process for validation purposes consisted of monitoring metallic sheets within a range of 0–35% (perforation rates), black-white (colors) and galvanized steel-aluminum (materials) in a large-scale test campaign. Excellent agreement was achieved between the outputs from the above-mentioned numerical model and the test campaign, sufficient for its validation. The behavior of different configurations will be described in a further paper, addressing their influence on cooling, heating and lighting loads in the building, with an Energyplus® model, which will be also validated with our theoretical model. Finally, additional parameters such as air-space width and location in the various climate zones defined for Spain will be carefully studied, for the optimization of design sustainability.

The commitments by the governments for the net zero emissions for the coming decades will be a huge challenge for the renewable sector all over the planet. Wind energy will play a significant role in this transition and scale-up, in both offshore and onshore, is a crucial step to move forward. The quick development of the new onshore wind turbine models in the race for the most powerful machine, the gradual increase in the hub height, and the unitary power of the new onshore wind turbines are producing modifications in different components of the turbines. This work presents a review of the onshore wind turbines foundations, especially about the different foundation design concepts available in the onshore business, the analysis of some of them and the trends.

The commitments by the governments for the net zero emissions for the coming decades will be a huge challenge for the renewable sector all over the planet. Wind energy will play a significant role in this transition and scale-up, in both offshore and onshore, is a crucial step to move forward. The quick development of the new onshore wind turbine models in the race for the most powerful machine, the gradual increase in the hub height, and the unitary power of the new onshore wind turbines are producing modifications in different components of the turbines. This work presents a review of the onshore wind turbines foundations, especially about the different foundation design concepts available in the onshore business, the analysis of some of them and the trends.

The increasing energy consumption levels of buildings within Europe call for controlled consumption and improvements to energy savings and efficiency and effective energy efficiency regulations. However, many aging and energy-inefficient buildings require energetic retrofitting that can employ various façades solutions and insulation materials. The selection of the most sustainable options in each situation therefore requires a decision-making methodology that can be used to prioritize available retrofit solutions based on economic, functional, environmental and social criteria. In this paper, both the methodology and the economic basis of the retrofitting process are presented. The methodology was validated in a case study, and a sensitivity analysis also demonstrated its validity, robustness and stability