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Project Goal: Develop a new eco-friendly and cost-effective insulation composite material based on recycled tyre rubber
Current Stage: On going
One strategy to increase energy efficiency of buildings could be the reduction of undesirable heat losses by mitigating the heat transfer mechanisms across the building envelope. The use of thermal insulation is the simplest and most straightforward way to promote thermal resistance of building elements by reducing the heat transfer by conduction. However, whenever there is an air cavity, radiation heat transfer could be also very relevant. The use of thermal reflective insulation materials inside the air gaps of building elements is likewise an effective way to increase thermal resistance without increasing weight and wall thickness. Some additional advantages are its low-cost and easy installation. In this work, the performance of a thermal reflective insulation system, constituted by an aluminium foil placed inside an air cavity between a double pane lightweight steel framed (LSF) partition, is experimentally evaluated for different air gap thicknesses, ranging from 0 mm up to 50 mm, with a step increment of 10 mm. We found a maximum thermal resistance improvement of the double pane LSF walls due to the reflective foil of around +0.529 m2∙°C/W (+21%). The measurements of the
Paulo Santos; Telmo Ribeiro. Thermal Performance of Double-Pane Lightweight Steel Framed Walls with and without a Reflective Foil. Buildings 2021, 11, 301 .
AMA StylePaulo Santos, Telmo Ribeiro. Thermal Performance of Double-Pane Lightweight Steel Framed Walls with and without a Reflective Foil. Buildings. 2021; 11 (7):301.
Chicago/Turabian StylePaulo Santos; Telmo Ribeiro. 2021. "Thermal Performance of Double-Pane Lightweight Steel Framed Walls with and without a Reflective Foil." Buildings 11, no. 7: 301.
Energy production still relies considerably on fossil fuels, and the building sector is a major player in the energy consumption market, mainly for space heating and cooling. Thermal bridges (TBs) in buildings are very relevant for the energy efficiency of buildings and may have an impact on heating energy needs of up to 30%. Given the high thermal conductivity of steel, the relevance of TBs in lightweight steel framed (LSF) components could be even greater. No research was found in the literature for evaluating how important the size and shape of steel studs are on the thermal performance of LSF building elements, which is the main objective of this work. This assessment is performed for the internal partitions and exterior façade of load-bearing LSF walls. The accuracy of the numerical model used in the simulations was verified and validated by comparison experimental measurements. Three reference steel studs were considered, six stud flange lengths and four steel thicknesses were evaluated, and five flange indentation sizes and four indent filling materials were assessed, corresponding to a total of 246 modelled LSF walls. It was concluded that the
Paulo Santos; Keerthan Poologanathan. The Importance of Stud Flanges Size and Shape on the Thermal Performance of Lightweight Steel Framed Walls. Sustainability 2021, 13, 3970 .
AMA StylePaulo Santos, Keerthan Poologanathan. The Importance of Stud Flanges Size and Shape on the Thermal Performance of Lightweight Steel Framed Walls. Sustainability. 2021; 13 (7):3970.
Chicago/Turabian StylePaulo Santos; Keerthan Poologanathan. 2021. "The Importance of Stud Flanges Size and Shape on the Thermal Performance of Lightweight Steel Framed Walls." Sustainability 13, no. 7: 3970.
Silica aerogels hold remarkable properties, particularly their translucence/transparency and extremely low thermal conductivity and density, for buildings thermal insulation purpose. Incorporated in composites or framing systems, they reduce the overall weight of the building envelope while increasing its thermal resistance, being especially valuable for energy-efficient retrofitting solutions, spanning from covering façades to window panes. This review presents the production process of silica aerogels in brief, their relevant properties regarding building’s needs, and a full survey of last years’ scientific achievements on silica aerogel-containing materials for buildings, such as panels, blankets, cement, mortars, concrete, glazing systems, solar collector covers, among others.
Alyne Lamy-Mendes; Ana Dora Rodrigues Pontinha; Patrícia Alves; Paulo Santos; Luisa Durães. Progress in silica aerogel-containing materials for buildings’ thermal insulation. Construction and Building Materials 2021, 286, 122815 .
AMA StyleAlyne Lamy-Mendes, Ana Dora Rodrigues Pontinha, Patrícia Alves, Paulo Santos, Luisa Durães. Progress in silica aerogel-containing materials for buildings’ thermal insulation. Construction and Building Materials. 2021; 286 ():122815.
Chicago/Turabian StyleAlyne Lamy-Mendes; Ana Dora Rodrigues Pontinha; Patrícia Alves; Paulo Santos; Luisa Durães. 2021. "Progress in silica aerogel-containing materials for buildings’ thermal insulation." Construction and Building Materials 286, no. : 122815.
A reliable evaluation of thermal behaviour and energy efficiency of buildings depends on the accurate thermal characterization of the envelope components. One of the most reliable methodologies to perform this thermal characterization is the measurements under laboratory-controlled conditions. The thermal performance assessment of lightweight steel-framed (LSF) building components exhibits particular additional challenges related to the strong thermal conductivity contrast between cavity insulation and steel frame materials, which may originate unwanted significant thermal bridge effects. The use of thermal break (TB) strips is one of the most currently used thermal bridge mitigation strategies. It was not found in the literature any experimental campaign for TB strips thermal performance evaluation in LSF elements. In this paper the thermal performance of twenty load-bearing (LB) and non-load-bearing (NLB) LSF walls configurations are measured, using the heat flow meter (HFM) method under controlled laboratory conditions. Three thermal break (TB) strip materials and three TB strip locations in the steel stud flanges are assessed. It was found that the inner and outer TB strips show very similar thermal performances, while double TB strips have a relative significant thermal performance increase. Aerogel was the best performance TB material, exhibiting a substantial improvement relatively to recycled rubber and cork/rubber composite TB strips. Furthermore, the TB strips performance was identical for the evaluated structural (LB) and non-structural (NLB) LSF walls.
Paulo Santos; Diogo Mateus. Experimental assessment of thermal break strips performance in load-bearing and non-load-bearing LSF walls. Journal of Building Engineering 2020, 32, 101693 .
AMA StylePaulo Santos, Diogo Mateus. Experimental assessment of thermal break strips performance in load-bearing and non-load-bearing LSF walls. Journal of Building Engineering. 2020; 32 ():101693.
Chicago/Turabian StylePaulo Santos; Diogo Mateus. 2020. "Experimental assessment of thermal break strips performance in load-bearing and non-load-bearing LSF walls." Journal of Building Engineering 32, no. : 101693.
Buildings are seeking renewable energy sources (e.g., solar) and passive devices, such as Trombe walls. However, the thermal performance of Trombe walls depends on many factors. In this work, the thermal behavior and energy efficiency of a Trombe wall in a lightweight steel frame compartment were evaluated, making use of in situ measurements and numerical simulations. Measurements were performed inside two real scale experimental identical cubic modules, exposed to natural exterior weather conditions. Simulations were made using validated advanced dynamic models. The winter Trombe wall benefits were evaluated regarding indoor air temperature increase and heating energy reduction. Moreover, a thermal behavior parametric study was performed. Several comparisons were made: (1) Sunny and cloudy winter week thermal behavior; (2) Office and residential space use heating energy; (3) Two heating set-points (20 °C and 18 °C); (4) Thickness of the Trombe wall air cavity; (5) Thickness of the thermal storage wall; (6) Dimensions of the interior upper/lower vents; (7) Material of the thermal storage wall. It was found that a Trombe wall device could significantly improve the thermal behavior and reduce heating energy consumption. However, if not well designed and controlled (e.g., to mitigate nocturnal heat losses), the Trombe wall thermal and energy benefits could be insignificant and even disadvantageous.
Victor Lohmann; Paulo Santos. Trombe Wall Thermal Behavior and Energy Efficiency of a Light Steel Frame Compartment: Experimental and Numerical Assessments. Energies 2020, 13, 2744 .
AMA StyleVictor Lohmann, Paulo Santos. Trombe Wall Thermal Behavior and Energy Efficiency of a Light Steel Frame Compartment: Experimental and Numerical Assessments. Energies. 2020; 13 (11):2744.
Chicago/Turabian StyleVictor Lohmann; Paulo Santos. 2020. "Trombe Wall Thermal Behavior and Energy Efficiency of a Light Steel Frame Compartment: Experimental and Numerical Assessments." Energies 13, no. 11: 2744.
An accurate evaluation of the thermal transmittance (U-value) of building envelope elements is fundamental for a reliable assessment of their thermal behaviour and energy efficiency. Simplified analytical methods to estimate the U-value of building elements could be very useful to designers. However, the analytical methods applied to lightweight steel framed (LSF) elements have some specific features, being more challenging to use and to obtain a reliable accurate U-value with. In this work, the main analytical methods available in the literature were identified, the calculation procedures were reviewed and their accuracy was evaluated and compared. With this goal, six analytical methods were used to estimate the U-values of 80 different LSF wall models. The obtained analytical U-values were compared with those provided by numerical simulations, which were used as reference U-values. The numerical simulations were performed using a 2D steady-state finite element method (FEM)-based software, THERM. The reliability of these numerical models was ensured by comparison with benchmark values and by an experimental validation. All the evaluated analytical methods showed a quite good accuracy performance, the worst accuracy being found in cold frame walls. The best and worst precisions were found in the Modified Zone Method and in the Gorgolewski Method 2, respectively. Very surprisingly, the ISO 6946 Combined Method showed a better average precision than other two methods, which were specifically developed for LSF elements.
Paulo Santos; Gabriela Lemes; Diogo Mateus. Analytical Methods to Estimate the Thermal Transmittance of LSF Walls: Calculation Procedures Review and Accuracy Comparison. Energies 2020, 13, 840 .
AMA StylePaulo Santos, Gabriela Lemes, Diogo Mateus. Analytical Methods to Estimate the Thermal Transmittance of LSF Walls: Calculation Procedures Review and Accuracy Comparison. Energies. 2020; 13 (4):840.
Chicago/Turabian StylePaulo Santos; Gabriela Lemes; Diogo Mateus. 2020. "Analytical Methods to Estimate the Thermal Transmittance of LSF Walls: Calculation Procedures Review and Accuracy Comparison." Energies 13, no. 4: 840.
Open-loop earth-air heat exchangers (EAHE) can be used as a passive contribution to reduce the energy demand of buildings for heating and cooling, by providing a thermal pre-conditioning of the required ventilation air. This paper aims to numerically assess the influence of three parameters on the overall thermal performance of an EAHE system for residential buildings in warm-summer Mediterranean climate: spacing between pipes, pipes diameter and flowing air velocity. ANSYS-CFX® was used to simulate the EAHE transient behaviour during heating and cooling operation modes, and to evaluate the influence of each parameter on the outlet air temperature and soil-air heat transfer rate. The numerical results were validated against experimental data and compared with previously obtained analytical results. It was concluded that for a certain pipe diameter and distance between adjacent pipes, the higher the air velocity the lower the thermal performance of the system, mainly for cooling. Results also showed that for a certain air velocity and pipe diameter, the distance between pipes can be reduced from 1.0 m to 0.5 m without compromising the EAHE performance, thus allowing a reduction of the land area needed for the EAHE pipes up to ca. 50%.
Nuno Rosa; Nelson Soares; J.J. Costa; P. Santos; Helena Gervasio. Assessment of an earth-air heat exchanger (EAHE) system for residential buildings in warm-summer Mediterranean climate. Sustainable Energy Technologies and Assessments 2020, 38, 100649 .
AMA StyleNuno Rosa, Nelson Soares, J.J. Costa, P. Santos, Helena Gervasio. Assessment of an earth-air heat exchanger (EAHE) system for residential buildings in warm-summer Mediterranean climate. Sustainable Energy Technologies and Assessments. 2020; 38 ():100649.
Chicago/Turabian StyleNuno Rosa; Nelson Soares; J.J. Costa; P. Santos; Helena Gervasio. 2020. "Assessment of an earth-air heat exchanger (EAHE) system for residential buildings in warm-summer Mediterranean climate." Sustainable Energy Technologies and Assessments 38, no. : 100649.
Light steel framed (LSF) construction is becoming widespread as a quick, clean and flexible construction system. However, these LSF elements need to be well designed and protected against undesired thermal bridges caused by the steel high thermal conductivity. To reduce energy consumption in buildings it is necessary to understand how heat transfer happens in all kinds of walls and their configurations, and to adequately reduce the heat loss through them by decreasing its thermal transmittance (U-value). In this work, numerical simulations are performed to assess different setups for two kinds of LSF walls: an interior partition wall and an exterior facade wall. Several parameters were evaluated separately to measure their influence on the wall U-value, and the addition of other elements was tested (e.g., thermal break strips) with the aim of achieving better thermal performances. The simulation modeling of a LSF interior partition with thermal break strips indicated a 24% U-value reduction in comparison with the reference case of using the LSF alone (U = 0.449 W/(m2.K)). However, when the clearance between the steel studs was simulated with only 300 mm there was a 29% increase, due to the increase of steel material within the wall structure. For exterior facade walls (U = 0.276 W/(m2.K)), the model with 80 mm of expanded polystyrene (EPS) in the exterior thermal insulation composite system (ETICS) reduced the thermal transmittance by 19%. Moreover, when the EPS was removed the U-value increased by 79%.
Paulo Santos; Gabriela Lemes; Diogo Mateus. Thermal Transmittance of Internal Partition and External Facade LSF Walls: A Parametric Study. Energies 2019, 12, 2671 .
AMA StylePaulo Santos, Gabriela Lemes, Diogo Mateus. Thermal Transmittance of Internal Partition and External Facade LSF Walls: A Parametric Study. Energies. 2019; 12 (14):2671.
Chicago/Turabian StylePaulo Santos; Gabriela Lemes; Diogo Mateus. 2019. "Thermal Transmittance of Internal Partition and External Facade LSF Walls: A Parametric Study." Energies 12, no. 14: 2671.
Given the great influence of the thermal transmittance of the building envelope on the overall thermal performance and energy efficiency of the building, it is essential to accurately determine the U-value of the main building envelope elements. Due to the great heterogeneity of the thermal conductivity of the elements presented in a lightweight steel-framed (LSF) wall, and to the geometric complexity of some steel framed structures, a reliable estimation of the thermal transmittance of LSF elements is even more challenging. Indeed, thermal bridging originated by steel studs must be considered in the assessment of the thermal transmittance of LSF walls. In this work, the thermal transmittance (U-value) of three LSF walls with different configurations will be investigated based on four different approaches: experimental laboratorial measurements based on the Heat Flow Meter (HFM) method; 3D finite element method (FEM) simulations using ANSYS CFX® software; 2D FEM-based simulations using THERM software; analytical estimations based on the ISO 6946 procedure for building components with inhomogeneous layers. Several verification procedures were performed to ensure the reliability of the results. It was found that a secondary wood stud can mitigate the thermal bridging effect of the steel frame and improve the LSF thermal performance, which is more noticeable when there is no thermal insulation. Furthermore, a good agreement was found between the results of the 2D FEM and the analytical ISO 6946 approaches for the LSF wall with only vertical steel studs.
Paulo Santos; Margarida Gonçalves; Cláudio Martins; Nelson Soares; José J. Costa. Thermal transmittance of lightweight steel framed walls: Experimental versus numerical and analytical approaches. Journal of Building Engineering 2019, 25, 100776 .
AMA StylePaulo Santos, Margarida Gonçalves, Cláudio Martins, Nelson Soares, José J. Costa. Thermal transmittance of lightweight steel framed walls: Experimental versus numerical and analytical approaches. Journal of Building Engineering. 2019; 25 ():100776.
Chicago/Turabian StylePaulo Santos; Margarida Gonçalves; Cláudio Martins; Nelson Soares; José J. Costa. 2019. "Thermal transmittance of lightweight steel framed walls: Experimental versus numerical and analytical approaches." Journal of Building Engineering 25, no. : 100776.
The experimental characterization of the overall thermal transmittance of homogeneous, moderately- and non-homogeneous walls, windows, and construction elements with innovative materials is very important to predict their thermal performance. It is also important to evaluate if the standard calculation methods to estimate the U-value of new and existing walls can be applied to more complex configurations, since the correct estimation of this value is a critical requirement when performing building energy simulations or energy audit. This paper provides a survey on the main methods to measure the thermal transmittance and thermal behaviour of construction elements, considering laboratory conditions and in-situ non-destructive measurements. Five methods are described: the heat flow meter (HFM); the guarded hot plate (GHP); the hot box (HB), considering the guarded HB (GHB) and the calibrated HB (CHB); and the infrared thermography (IRT). Then, previous studies dedicated to the assessment of the thermal performance of different heavy- and light-weight walls are discussed. Particular attention is devoted to the measurement of the U-value of non-homogeneous walls, including the effect of thermal bridging caused by steel framing or mortar joints, and the presence of PCMs or new insulation materials in the configuration of the walls.
Nelson Soares; Cláudio Martins; Margarida Gonçalves; Paulo Santos; Luís Simões da Silva; José J. Costa. Laboratory and in-situ non-destructive methods to evaluate the thermal transmittance and behavior of walls, windows, and construction elements with innovative materials: A review. Energy and Buildings 2018, 182, 88 -110.
AMA StyleNelson Soares, Cláudio Martins, Margarida Gonçalves, Paulo Santos, Luís Simões da Silva, José J. Costa. Laboratory and in-situ non-destructive methods to evaluate the thermal transmittance and behavior of walls, windows, and construction elements with innovative materials: A review. Energy and Buildings. 2018; 182 ():88-110.
Chicago/Turabian StyleNelson Soares; Cláudio Martins; Margarida Gonçalves; Paulo Santos; Luís Simões da Silva; José J. Costa. 2018. "Laboratory and in-situ non-destructive methods to evaluate the thermal transmittance and behavior of walls, windows, and construction elements with innovative materials: A review." Energy and Buildings 182, no. : 88-110.
Lightweight steel-framed (LSF) construction has the potential to reach high standards regarding the functional performance of buildings. Despite the benefits of this construction system, the effect of thermal bridges caused by the high thermal conductivity of the steel structure can be a disadvantage. Furthermore, because LSF buildings have low mass and the connections between the outer and the inner sheathing of the walls are usually rigid, provided by steel studs, some acoustic performance drawbacks are also possible. Excessive heat loss or poor sound insulation are related to the external envelope behavior of buildings. Although several studies can be found regarding the influence of the steel frame on the thermal or sound insulation performance of LSF façade walls, the study of this influence from both perspectives at the same time is not widespread. In this work, the influence of the steel frame on both the thermal and sound insulation performance of LSF façade walls is studied. The thermal behavior and sound insulation are assessed using specialized software, namely THERM and INSUL, respectively. With this work it is intended to provide guidelines which can contribute to an effective design of LSF façade walls, considering both functional performances.
Eduardo Roque; Paulo Santos; Andreia Carvalho Pereira. Thermal and sound insulation of lightweight steel-framed façade walls. Science and Technology for the Built Environment 2018, 25, 156 -176.
AMA StyleEduardo Roque, Paulo Santos, Andreia Carvalho Pereira. Thermal and sound insulation of lightweight steel-framed façade walls. Science and Technology for the Built Environment. 2018; 25 (2):156-176.
Chicago/Turabian StyleEduardo Roque; Paulo Santos; Andreia Carvalho Pereira. 2018. "Thermal and sound insulation of lightweight steel-framed façade walls." Science and Technology for the Built Environment 25, no. 2: 156-176.
Earth-to-air heat exchanger is an efficient complement to the space heating and cooling systems. An earth-to-air heat exchanger system consists of a set of subterranean pipes leading outdoor air to a ventilation room and by collecting geothermal energy saves some energy. This article presents testing of an earth-to-air heat exchanger installation in a residential building in Coimbra (Portugal) during 1 year. An analytical model is developed and verified with data from the system monitoring. Many variables affect the outcome of the model and they are included in the parametric study, namely, pipe length and diameter, air velocity, pipe wall material and type of soil. While the difference between outlet and inlet air temperatures is proportional to the pipe length and ground thermal conductivity and inversely proportional to pipe diameter and air velocity, the evaluation is made in terms of a coefficient of performance. For that, the most important factor is the air velocity while material of the pipe does not have a significant effect.
Nuno Rosa; P Santos; José J. Costa; Helena Gervasio. Modelling and performance analysis of an earth-to-air heat exchanger in a pilot installation. Journal of Building Physics 2018, 42, 259 -287.
AMA StyleNuno Rosa, P Santos, José J. Costa, Helena Gervasio. Modelling and performance analysis of an earth-to-air heat exchanger in a pilot installation. Journal of Building Physics. 2018; 42 (3):259-287.
Chicago/Turabian StyleNuno Rosa; P Santos; José J. Costa; Helena Gervasio. 2018. "Modelling and performance analysis of an earth-to-air heat exchanger in a pilot installation." Journal of Building Physics 42, no. 3: 259-287.
José Henriques; Nuno Rosa; Helena Gervasio; Paulo Santos; Luis Simoesdasilva. Structural performance of light steel framing panels using screw connections subjected to lateral loading. Thin-Walled Structures 2017, 121, 67 -88.
AMA StyleJosé Henriques, Nuno Rosa, Helena Gervasio, Paulo Santos, Luis Simoesdasilva. Structural performance of light steel framing panels using screw connections subjected to lateral loading. Thin-Walled Structures. 2017; 121 ():67-88.
Chicago/Turabian StyleJosé Henriques; Nuno Rosa; Helena Gervasio; Paulo Santos; Luis Simoesdasilva. 2017. "Structural performance of light steel framing panels using screw connections subjected to lateral loading." Thin-Walled Structures 121, no. : 67-88.
The improvement of the use of renewable energy sources, such as solar thermal energy, and the reduction of energy demand during the several stages of buildings' life cycle is crucial towards a more sustainable built environment. This paper presents an overview of the main features of lightweight steel-framed (LSF) construction with cold-formed elements from the point of view of life cycle energy consumption. The main LSF systems are described and some strategies for reducing thermal bridges and for improving the thermal resistance of LSF envelope elements are presented. Several passive strategies for increasing the thermal storage capacity of LSF solutions are discussed and particular attention is devoted to the incorporation of phase change materials (PCMs). These materials can be used to improve indoor thermal comfort, to reduce the energy demand for air-conditioning and to take advantage of solar thermal energy. The importance of reliable dynamic and holistic simulation methodologies to assess the energy demand for heating and cooling during the operational phase of LSF buildings is also discussed. Finally, the life cycle assessment (LCA) and the environmental performance of LSF construction are reviewed to discuss the main contribution of this kind of construction towards more sustainable buildings
N. Soares; P. Santos; H. Gervásio; J.J. Costa; L. Simões da Silva. Energy efficiency and thermal performance of lightweight steel-framed (LSF) construction: A review. Renewable and Sustainable Energy Reviews 2017, 78, 194 -209.
AMA StyleN. Soares, P. Santos, H. Gervásio, J.J. Costa, L. Simões da Silva. Energy efficiency and thermal performance of lightweight steel-framed (LSF) construction: A review. Renewable and Sustainable Energy Reviews. 2017; 78 ():194-209.
Chicago/Turabian StyleN. Soares; P. Santos; H. Gervásio; J.J. Costa; L. Simões da Silva. 2017. "Energy efficiency and thermal performance of lightweight steel-framed (LSF) construction: A review." Renewable and Sustainable Energy Reviews 78, no. : 194-209.
In order to assess sustainability of buildings, environmental, economic and social aspects should be addressed. Within the evaluation of the social criteria, regarding a building in the use stage, the standard EN 15643–3:2012 defines, as a general methodology, a list of performance categories to be addressed. General guidelines for the evaluation of these performance categories are provided by standard EN 16309:2014, and its effective assessment is mainly based on qualitative criteria and a checklist approach, which does not enable an easy comparability of the results of different assessments. Therefore, the aim of this paper is to perform a social life cycle assessment of school buildings for higher education, focusing on the criterion of health and comfort, which addresses different sub-criteria. In the proposed methodology different levels of assessment were defined. In the first level are each one of the sub-criteria for health and comfort (e.g. thermal characteristics), being this evaluation based on a bottom-to-up approach. For some of the sub-criteria, there are recommendations, stablished in standards or technical codes, which were followed to define this methodology at baseline level. The Analytical hierarchic process (AHP) was used to overcome the lack of reference values for the assessment of the remaining sub-criteria. Within each assessment level, a multi-criteria approach was required to reach a score. The list of weights to be used requires an expert sensibility. A comprehensive survey based on an AHP method was used as reference at the top-level evaluation, to obtain the weighting scheme to rate social performance.
P. Santos; A. Carvalho Pereira; H. Gervásio; A. Bettencourt; D. Mateus. Assessment of health and comfort criteria in a life cycle social context: Application to buildings for higher education. Building and Environment 2017, 123, 625 -648.
AMA StyleP. Santos, A. Carvalho Pereira, H. Gervásio, A. Bettencourt, D. Mateus. Assessment of health and comfort criteria in a life cycle social context: Application to buildings for higher education. Building and Environment. 2017; 123 ():625-648.
Chicago/Turabian StyleP. Santos; A. Carvalho Pereira; H. Gervásio; A. Bettencourt; D. Mateus. 2017. "Assessment of health and comfort criteria in a life cycle social context: Application to buildings for higher education." Building and Environment 123, no. : 625-648.
Lightweight steel-framed (LSF) construction, given its advantages, has the potential to reach high standards in energy and environmental performance of buildings, such as nearly zero-energy buildings (nZEB). When compared with traditional construction, LSF system offers distinct benefits in such fields as sustainability, cost-effectiveness, constructive process, and safety at work. Despite the benefits of this constructive system, the effect of thermal bridges in LSF elements, caused by the high thermal conductivity of the steel structure, can be a disadvantage. The excessive heat losses or gains through these thermal bridges are more relevant in buildings’ exterior envelope, such as facade walls. These building components’ thermal performance is crucial in the buildings’ overall energetic behaviour, with a direct impact on energy consumption and resulting monetary costs during their operational stage. In this work the influence of the thermal insulation position on its effectiveness is evaluated in LSF facade walls. For this purpose, several LSF wall types are assessed, namely cold, warm, and hybrid construction. The influence of thermal bridges instigated by the steel studs in the LSF walls’ overall thermal performance is evaluated as well. The computations are performed using specialized finite element software (THERM).
Eduardo Roque; Paulo Santos. The Effectiveness of Thermal Insulation in Lightweight Steel-Framed Walls with Respect to Its Position. Buildings 2017, 7, 13 .
AMA StyleEduardo Roque, Paulo Santos. The Effectiveness of Thermal Insulation in Lightweight Steel-Framed Walls with Respect to Its Position. Buildings. 2017; 7 (4):13.
Chicago/Turabian StyleEduardo Roque; Paulo Santos. 2017. "The Effectiveness of Thermal Insulation in Lightweight Steel-Framed Walls with Respect to Its Position." Buildings 7, no. 4: 13.
Paulo Santos. Energy Efficiency of Lightweight Steel-Framed Buildings. Energy Efficient Buildings 2017, 1 .
AMA StylePaulo Santos. Energy Efficiency of Lightweight Steel-Framed Buildings. Energy Efficient Buildings. 2017; ():1.
Chicago/Turabian StylePaulo Santos. 2017. "Energy Efficiency of Lightweight Steel-Framed Buildings." Energy Efficient Buildings , no. : 1.
Currently, sustainable development and the search for green and renewable energy sources are two of the top priorities of humankind. As it is known, the construction industry has a major role to the global economy, but is also one of the most relevant regarding waste production and resource depletion. For example, buildings have an important share in energy consumption and greenhouse gas emissions (near 40% in Europe), being essential for the global sustainable development. The life cycle assessment (LCA) of buildings should be done in the early stages of design, increasing the potential to effectively influence the life cycle performance of the building, mitigating its environmental impacts. However, this is not an easy task mainly given the lack of information in the initial stages of design and the challenge to accurately predict the operational energy consumption during the use phase of the building. One of the main goals of the research project “SB_Steel – Sustainable building project in steel” funded by the research fund for coal and steel (RFCS) was to develop a new tool for a simplified assessment of building sustainability at early design stages. In this paper the implemented tool, which is now available on-line, is described and the implemented methodology is justified. The use of the simplified tool is illustrated by a case-study. The inputs/outputs of the tool are described. The limitations and some improvement suggestions of the simplified approach are discussed.
Paulo Santos; Helena Gervásio; Luís Simões Da Silva. A simplified tool to evaluate the sustainability of buildings in steel in early stages of design. Matériaux & Techniques 2016, 104, 103 .
AMA StylePaulo Santos, Helena Gervásio, Luís Simões Da Silva. A simplified tool to evaluate the sustainability of buildings in steel in early stages of design. Matériaux & Techniques. 2016; 104 (1):103.
Chicago/Turabian StylePaulo Santos; Helena Gervásio; Luís Simões Da Silva. 2016. "A simplified tool to evaluate the sustainability of buildings in steel in early stages of design." Matériaux & Techniques 104, no. 1: 103.
This paper evaluates the heat transfer through small thermal energy storage (TES) units filled with different phase change materials (PCMs): free-form and microencapsulated PCMs. The experimental results are very useful for benchmarking and validation of numerical models to be used in the design and optimization of new TES systems for buildings. They also allow discussing which arrangement/PCM is better for specific building applications considering the thermal regulation effect during charging, the influence of subcooling during discharging, and the influence of natural convection during both processes. During charging, the influence of the aspect ratio of the cavities on three parameters is investigated: control-temperature on the hot surface; thermal-regulation period; time required for melting the PCM in the mid-plane. During discharging, five parameters are evaluated: time for solidifying the PCM in the mid-plane; time for starting crystallization; subcooling period; phase-change temperature after subcooling; difference between the solidifying temperature and the cooled temperature due to subcooling. It was concluded that natural convection in the free-form PCM must be considered in any simulation to well describe the charging process. During discharging, subcooling must also be considered. The effects of natural convection and subcooling can be neglected when modelling cavities filled with the microencapsulated PCM.
N. Soares; Adélio Gaspar; Paulo Santos; José J. Costa. Experimental evaluation of the heat transfer through small PCM-based thermal energy storage units for building applications. Energy and Buildings 2016, 116, 18 -34.
AMA StyleN. Soares, Adélio Gaspar, Paulo Santos, José J. Costa. Experimental evaluation of the heat transfer through small PCM-based thermal energy storage units for building applications. Energy and Buildings. 2016; 116 ():18-34.
Chicago/Turabian StyleN. Soares; Adélio Gaspar; Paulo Santos; José J. Costa. 2016. "Experimental evaluation of the heat transfer through small PCM-based thermal energy storage units for building applications." Energy and Buildings 116, no. : 18-34.