This page has only limited features, please log in for full access.

Dr. Nelson Soares
Department of Mechanical Engineering, University of Coimbra, 3000 Coimbra, Portugal

Basic Info


Research Keywords & Expertise

0 Building Physics
0 Heat Transfer
0 Sustainability
0 Sustainable Construction
0 LSF construction

Fingerprints

Phase change materials (PCM)
Heat Transfer
Sustainability
LSF construction
Dynamic simulation of energy in buildings

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Review
Published: 14 February 2021 in Sustainability
Reads 0
Downloads 0

In higher-education world heritage sites, the conservation and energy retrofitting of heritage buildings (HBs) is an important vector for their development, competitiveness and welfare. To guarantee their ongoing use, these buildings must be adapted to face current and emerging societal challenges: (i) the conservation of cultural heritage and the maintenance of their original characteristics and identity; (ii) the transformation of heritage sites into tourist centers that energize the local economy, generating revenue and jobs; (iii) the adaptation of the buildings to new uses and functions that demand energy retrofitting strategies to satisfy today’s standards of thermal comfort, indoor environmental quality (IEQ) and energy efficiency; (iv) tackling impacts of climate change, particularly global warming and extreme weather events; and finally, (v) the implementation of strategies to mitigate the impact of a growing number of tourists. The combined implications of these challenges require a comprehensive approach with interrelated measures strongly reliant on the use of technology and innovation. This work aims to discuss how higher-education cultural HBs can be rethought to serve these expectations. Moreover, a multidisciplinary intervention framework is provided to discuss how HBs can respond to the challenges and risks of rehabilitation, energy retrofitting, climate change and increasing tourism.

ACS Style

Luisa Dias Pereira; Vanessa Tavares; Nelson Soares. Up-To-Date Challenges for the Conservation, Rehabilitation and Energy Retrofitting of Higher Education Cultural Heritage Buildings. Sustainability 2021, 13, 2061 .

AMA Style

Luisa Dias Pereira, Vanessa Tavares, Nelson Soares. Up-To-Date Challenges for the Conservation, Rehabilitation and Energy Retrofitting of Higher Education Cultural Heritage Buildings. Sustainability. 2021; 13 (4):2061.

Chicago/Turabian Style

Luisa Dias Pereira; Vanessa Tavares; Nelson Soares. 2021. "Up-To-Date Challenges for the Conservation, Rehabilitation and Energy Retrofitting of Higher Education Cultural Heritage Buildings." Sustainability 13, no. 4: 2061.

Journal article
Published: 14 February 2021 in Journal of Building Engineering
Reads 0
Downloads 0

The life cycle assessment (LCA) methodology has been extensively used to assess the environmental influence of alternative building construction; however, the influence of building design has seldom been assessed for Mediterranean climate. This article aims to evaluate the influence of three, often neglected, design options on the life cycle (LC) energy and environmental impacts of a south European single-family house: solar orientation, window sizing, and building shape. Using a parametric attributional LCA, the house's materials, construction, maintenance, and operation (heating and cooling) are analysed for different design scenarios. Annual operational energy, LC non-renewable primary energy (NRPE) and environmental LC impact assessment (LCIA) results are presented and discussed. Results show that embodied energy generally surpasses operational energy. Building orientation has less influence on LCIA results than on operational energy, particularly for compact shapes. Scenarios with bigger Window-to-Wall Ratio (WWR) have higher embodied impacts, being more sensitive to orientation due to solar gains. Lower WWR (5%) can be used to reduce the overall LC impacts, especially in houses with lower operational patterns. A compact shape building was shown to reduce heating impact, while a terraced and less compact shape reduces cooling impact. Compared with literature, this study reveals that, from a LC perspective, design options are as significant as construction options. Finally, design recommendations should be based on LCA and not only on operational results; nevertheless, a LCA single indicator (NRPE or Global Warming Potential) can be used to support decisions for alternative house designs with similar construction.

ACS Style

Helena Monteiro; Fausto Freire; Nelson Soares. Life cycle assessment of a south European house addressing building design options for orientation, window sizing and building shape. Journal of Building Engineering 2021, 39, 102276 .

AMA Style

Helena Monteiro, Fausto Freire, Nelson Soares. Life cycle assessment of a south European house addressing building design options for orientation, window sizing and building shape. Journal of Building Engineering. 2021; 39 ():102276.

Chicago/Turabian Style

Helena Monteiro; Fausto Freire; Nelson Soares. 2021. "Life cycle assessment of a south European house addressing building design options for orientation, window sizing and building shape." Journal of Building Engineering 39, no. : 102276.

Journal article
Published: 03 August 2020 in International Journal of Thermal Sciences
Reads 0
Downloads 0

This paper assesses the thermal performance of four microencapsulated-PCM-based samples that can be used in the design of new thermal energy storage systems for buildings: a PCM-enhanced plasterboard; three different fin-enhanced aluminium containers filled with the PCM. The methodology covers: the thermophysical characterization of the PCM-based products; the development of charging and discharging experiments to provide data for numerical validation purposes; the numerical modelling considering five different methods dispersed in literature, and a new-improved method. The main goals are to validate the numerical predictions against reliable experimental results and to find out which method is preferable for future simulations. The 3D numerical simulations were based on the effective heat capacity (EHC), additional heat source (AHS) and enthalpy (H-P) approaches. The first two methods were implemented in ANSYS CFX®; the other in ANSYS FLUENT®. For the EHC method, four different ways to specify the variation of the effective specific heat with temperature were assessed. While the H-P commercial code already implemented in ANSYS FLUENT® was used, the other two methods implemented in ANSYS CFX® were developed and validated for the purpose of this study. Good agreement between numerical and experimental results was achieved for all numerical approaches. In fact, it was concluded that the six numerical methods can be used to simulate heat diffusion with solid-liquid phase-changes. However, it was verified that the EHC method with the triangular or the self-adjusted triangular profiles is preferable for both charging and discharging simulations, since it can be drawn based on few information about the PCM-based products; it ensures good predictions of both charging/discharging kinetics and stored/released energy; it can be used without compromising computation time in comparison to other methods. The EHC method with the rectangular profile, recurrently used in literature, exhibits some convergence issues whose resolution has required longer computation times.

ACS Style

N. Soares; Nuno Rosa; J.J. Costa; A.G. Lopes; T. Matias; P.N. Simões; L. Durães. Validation of different numerical models with benchmark experiments for modelling microencapsulated-PCM-based applications for buildings. International Journal of Thermal Sciences 2020, 159, 106565 .

AMA Style

N. Soares, Nuno Rosa, J.J. Costa, A.G. Lopes, T. Matias, P.N. Simões, L. Durães. Validation of different numerical models with benchmark experiments for modelling microencapsulated-PCM-based applications for buildings. International Journal of Thermal Sciences. 2020; 159 ():106565.

Chicago/Turabian Style

N. Soares; Nuno Rosa; J.J. Costa; A.G. Lopes; T. Matias; P.N. Simões; L. Durães. 2020. "Validation of different numerical models with benchmark experiments for modelling microencapsulated-PCM-based applications for buildings." International Journal of Thermal Sciences 159, no. : 106565.

Journal article
Published: 07 February 2020 in Sustainable Energy Technologies and Assessments
Reads 0
Downloads 0

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%.

ACS Style

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 Style

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.

Chicago/Turabian Style

Nuno 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.

Journal article
Published: 28 December 2019 in Energy and Buildings
Reads 0
Downloads 0

This paper provides an overview on how phase change materials (PCMs) can be used for the thermal regulation of photovoltaic (PV) devices, and describes an experimental apparatus to assess whether the performance of 250 W STC-rated commercial polycrystalline silicon PV panels can be improved by placing movable thermal energy storage (TES) units filled with the free-form PCM RT 22 HC on the panels' back. The outdoor apparatus is located at Coimbra, Portugal. Three identical PV panels were separately installed and individually monitored: one panel was taken as reference; the other two were considered together with a TES unit each with horizontally and vertically oriented cavities, PV/PCM1 and PV/PCM2 systems, respectively. The time evolutions of the temperature of the PV panels were compared with each other to analyse the possible thermal regulation potential of the TES units. The time evolution of the power output was also assessed to compare the efficiency of the different systems. Finally, the energy produced per day by each system was evaluated. The results showed that the PV operating temperature has increased ca. 16–21 °C and 14–18 °C in the PV/PCM1 and PV/PCM2 systems, respectively, in comparison with the reference PV panel (at peak time). Moreover, the daily energy produced by the PV panel of the PV/PCM1 and PV/PCM2 systems was, respectively, 3.3–6.5% and 3.3–6.0% lower than that produced by the reference PV panel during the measured short-term summer operation period. Therefore, it was concluded that the movable TES units have a negative impact on the performance of the PV/PCM systems, and that a PCM with a higher phase change temperature must be chosen for Mediterranean climate.

ACS Style

N. Soares; José J. Costa; A.R. Gaspar; T. Matias; Pedro Nuno Nl Simões; Luisa Durães. Can movable PCM-filled TES units be used to improve the performance of PV panels? Overview and experimental case-study. Energy and Buildings 2019, 210, 109743 .

AMA Style

N. Soares, José J. Costa, A.R. Gaspar, T. Matias, Pedro Nuno Nl Simões, Luisa Durães. Can movable PCM-filled TES units be used to improve the performance of PV panels? Overview and experimental case-study. Energy and Buildings. 2019; 210 ():109743.

Chicago/Turabian Style

N. Soares; José J. Costa; A.R. Gaspar; T. Matias; Pedro Nuno Nl Simões; Luisa Durães. 2019. "Can movable PCM-filled TES units be used to improve the performance of PV panels? Overview and experimental case-study." Energy and Buildings 210, no. : 109743.

Journal article
Published: 21 April 2019 in Journal of Building Engineering
Reads 0
Downloads 0

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.

ACS Style

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 Style

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.

Chicago/Turabian Style

Paulo 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.

Review
Published: 23 October 2018 in Energy and Buildings
Reads 0
Downloads 0

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.

ACS Style

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 Style

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.

Chicago/Turabian Style

Nelson 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.

Journal article
Published: 09 August 2018 in Energy and Buildings
Reads 0
Downloads 0

European countries impose regulations for low thermal transmittance envelopes to improve the buildings’ energy efficiency. However, in scientific literature, evidences are surfacing that such low U-values are affecting the validity of traditional design guidelines. The purpose of this paper is to analyze the implications of lowering the envelope U-values. To achieve this, 96 000 residential buildings were generated, with random geometries and U-values, and their energy consumption evaluated for eight European locations. The buildings were grouped according to the envelope elements’ thermal transmittance and the results statistically analyzed. For each group, six geometry-based indexes were correlated with the energy performance. As U-values decrease, the performance variation amplitude was found to reduce, making the geometry less important. However, in warm/moderate climates, low U-values tend to actually increase the energy consumption and also rise the performance variation, meaning that geometry regains importance. In this case, instead of helping reducing the heating demands, solar exposed windows and compact geometries raise the energy consumption. It is concluded that, for each climate location, there is an ideal U-value range for which the energy demand is low and the geometry effect becomes less significant, thus freeing designers to further explore building forms and window designs.

ACS Style

Eugénio Rodrigues; Marco Fernandes; Nelson Soares; Álvaro Gomes; Adélio Rodrigues Gaspar; José J. Costa. The potential impact of low thermal transmittance construction on the European design guidelines of residential buildings. Energy and Buildings 2018, 178, 379 -390.

AMA Style

Eugénio Rodrigues, Marco Fernandes, Nelson Soares, Álvaro Gomes, Adélio Rodrigues Gaspar, José J. Costa. The potential impact of low thermal transmittance construction on the European design guidelines of residential buildings. Energy and Buildings. 2018; 178 ():379-390.

Chicago/Turabian Style

Eugénio Rodrigues; Marco Fernandes; Nelson Soares; Álvaro Gomes; Adélio Rodrigues Gaspar; José J. Costa. 2018. "The potential impact of low thermal transmittance construction on the European design guidelines of residential buildings." Energy and Buildings 178, no. : 379-390.

Review article
Published: 27 July 2018 in Renewable and Sustainable Energy Reviews
Reads 0
Downloads 0

This paper brings together several contemporary topics in energy systems aiming to provide a literature review based reflection on how several interrelated energy systems can contribute together to a more sustainable world. Some directions are discussed, such as the improvement of the energy efficiency and environmental performance of systems, the development of new technologies, the increase of the use of renewable energy sources, the promotion of holistic and multidisciplinary studies, and the implementation of new management rules and "eco-friendly and sustainable" oriented policies at different scales. The interrelations of the diverse energy systems are also discussed in order to address their main social, economic and environmental impacts. The subjects covered include the assessment of the electricity market and its main players (demand, supply, distribution), the evaluation of urban systems (buildings, transportation, commuting), the analysis of the implementation of renewable energy cooperatives, the discussion of the diffusion of the electric vehicle and the importance of new bioenergy systems. This paper also presents relevant research carried out in the framework of the Energy for Sustainability (EfS) Initiative of the University of Coimbra, linking the reviewed areas to the multidisciplinary approach adopted by the EfS Initiative. To conclude, several research topics that should be addressed in the near future are proposed.

ACS Style

N. Soares; A.G. Martins; A.L. Carvalho; C. Caldeira; C. Du; É. Castanheira; E. Rodrigues; G. Oliveira; Guillermo Ivan Pereira; Joana Bastos; J.P. Ferreira; Lauro André Ribeiro; N.C. Figueiredo; N. Šahović; Pedro Miguel; R. Garcia. The challenging paradigm of interrelated energy systems towards a more sustainable future. Renewable and Sustainable Energy Reviews 2018, 95, 171 -193.

AMA Style

N. Soares, A.G. Martins, A.L. Carvalho, C. Caldeira, C. Du, É. Castanheira, E. Rodrigues, G. Oliveira, Guillermo Ivan Pereira, Joana Bastos, J.P. Ferreira, Lauro André Ribeiro, N.C. Figueiredo, N. Šahović, Pedro Miguel, R. Garcia. The challenging paradigm of interrelated energy systems towards a more sustainable future. Renewable and Sustainable Energy Reviews. 2018; 95 ():171-193.

Chicago/Turabian Style

N. Soares; A.G. Martins; A.L. Carvalho; C. Caldeira; C. Du; É. Castanheira; E. Rodrigues; G. Oliveira; Guillermo Ivan Pereira; Joana Bastos; J.P. Ferreira; Lauro André Ribeiro; N.C. Figueiredo; N. Šahović; Pedro Miguel; R. Garcia. 2018. "The challenging paradigm of interrelated energy systems towards a more sustainable future." Renewable and Sustainable Energy Reviews 95, no. : 171-193.

Journal article
Published: 05 March 2018 in Energy for Sustainable Development
Reads 0
Downloads 0

This paper presents a study on the application of lightweight steel framed (LSF) construction systems in hot climate. A generative design method created 6010 houses, with random geometry and random roof and exterior wall types with different insulation levels, and EnergyPlus was used to evaluate the energy consumption for air-conditioning of each building. The main goals were to determine which geometric variables correlate with the energy performance, and to provide some guidelines to foster efficient LSF buildings in hot climates. By correlating six geometry-based indexes with the energy consumption for each construction element type group, it was verified that roofs do not show significant correlation, while exterior walls presented weak to moderate positive correlation with the building volume, very weak to weak negative correlation with the relative compactness, no correlation with the shape coefficient, moderate to strong negative correlation with the window-to-floor, window-to-wall, and window-to-exterior surface ratios. The results also show that buildings with larger windows and greater level of insulation have better energy performance. No significant difference of energy performance was found between different LSF construction systems with equivalent thermal resistance.

ACS Style

Eugénio Rodrigues; Nelson Soares; Marco Fernandes; Adélio Rodrigues Gaspar; Alvaro Gomes; José J. Costa. An integrated energy performance-driven generative design methodology to foster modular lightweight steel framed dwellings in hot climates. Energy for Sustainable Development 2018, 44, 21 -36.

AMA Style

Eugénio Rodrigues, Nelson Soares, Marco Fernandes, Adélio Rodrigues Gaspar, Alvaro Gomes, José J. Costa. An integrated energy performance-driven generative design methodology to foster modular lightweight steel framed dwellings in hot climates. Energy for Sustainable Development. 2018; 44 ():21-36.

Chicago/Turabian Style

Eugénio Rodrigues; Nelson Soares; Marco Fernandes; Adélio Rodrigues Gaspar; Alvaro Gomes; José J. Costa. 2018. "An integrated energy performance-driven generative design methodology to foster modular lightweight steel framed dwellings in hot climates." Energy for Sustainable Development 44, no. : 21-36.

Review
Published: 01 October 2017 in Renewable and Sustainable Energy Reviews
Reads 0
Downloads 0

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

ACS Style

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 Style

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.

Chicago/Turabian Style

N. 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.

Review
Published: 09 May 2017 in Renewable and Sustainable Energy Reviews
Reads 0
Downloads 0

Nowadays, debates addressing climate change, fossil fuels depletion and energy security highlight the need for a more sustainable built environment in order to reduce energy consumption and emission trends in the buildings sector. Meeting these targets is a challenge that calls for innovative research to improve the use of renewable energy sources, new technologies, and holistic tools and methodologies. Such research should integrate the dynamics and main drivers of energy supply and demand in buildings to support new policies, plans and actions towards lowering the built environment burdens. This paper brings together ten research topics concerning the energy and environmental performance of buildings, which can support a shift towards a more sustainable built environment. Background information and state of the art literature on the covered research topics is briefly summarized, gaps are identified and guidelines for future research are provided. The selected topics cover different stages along the lifetime of buildings (from design and operation, to retrofitting and end-of-life), different scale approaches (from building elements/components, to the building, district and urban scales), and different methods to assess the energy and environmental performance of buildings (life-cycle assessment, generative design methods and retrofitting tools). Other topics are discussed such as: nearly zero-energy buildings, the control of domestic energy resources in smart grid scenarios, the need to include end-users' behaviors in the dynamics of energy demand, the advantages of improving thermal storage by using phase change materials, the importance of reducing heating and cooling energy demand (maintaining indoor thermal comfort), and the optimization of heating and cooling fluids, and their system control.

ACS Style

Nelson Soares; Joana Bastos; L. Dias Pereira; A. Soares; Ana Rita Amaral; E. Asadi; Eugénio Rodrigues; F.B. Lamas; Helena Monteiro; M.A.R. Lopes; Adélio Gaspar. A review on current advances in the energy and environmental performance of buildings towards a more sustainable built environment. Renewable and Sustainable Energy Reviews 2017, 77, 845 -860.

AMA Style

Nelson Soares, Joana Bastos, L. Dias Pereira, A. Soares, Ana Rita Amaral, E. Asadi, Eugénio Rodrigues, F.B. Lamas, Helena Monteiro, M.A.R. Lopes, Adélio Gaspar. A review on current advances in the energy and environmental performance of buildings towards a more sustainable built environment. Renewable and Sustainable Energy Reviews. 2017; 77 ():845-860.

Chicago/Turabian Style

Nelson Soares; Joana Bastos; L. Dias Pereira; A. Soares; Ana Rita Amaral; E. Asadi; Eugénio Rodrigues; F.B. Lamas; Helena Monteiro; M.A.R. Lopes; Adélio Gaspar. 2017. "A review on current advances in the energy and environmental performance of buildings towards a more sustainable built environment." Renewable and Sustainable Energy Reviews 77, no. : 845-860.

Journal article
Published: 16 January 2017 in Building Simulation
Reads 0
Downloads 0

Between 2000 and 2015, annual electric peak demand in Kuwait has doubled to 15000 MW and the Ministry of Energy and Water expects this number to double once more by 2030 attributing 70% of this growth to new housing projects. Within this context, this manuscript evaluates the effect of incorporating PCM-wallboards in low-rise air-conditioned residential heavyweight buildings in Kuwait. Using an EnergyPlus single-zone model, a parametric study is performed considering several window-to-wall ratios (WWRs), different solar orientations and some PCM-wallboards configurations. The main study goals are to: (i) explore the validity of a single PCM-wallboard solution that can be universally applied throughout residential buildings in Kuwait; (ii) evaluate the impact of PCMwallboard on the reduction of both cooling demand and peak-loads; (iii) provide some guidelines for incorporating PCM-wallboards in Kuwait. Following an extensive parametric study, a 4 cm thick PCM-wallboard with a melting-peak temperature of 24 °C yielded the lowest annual cooling demand across a variety of room orientations and WWRs assuming cooling setpoint of 24 °C. Its implementation led to annual cooling energy savings of 4%–5% across all the case-studies. Regarding the impact throughout the year, cooling demand and peak-loads can be reduced by 5%–7% during summer months. The average daily cooling loads can be reduced by 5%–8%

ACS Style

Nelson Soares; Christoph F. Reinhart; Ali Hajiah. Simulation-based analysis of the use of PCM-wallboards to reduce cooling energy demand and peak-loads in low-rise residential heavyweight buildings in Kuwait. Building Simulation 2017, 10, 481 -495.

AMA Style

Nelson Soares, Christoph F. Reinhart, Ali Hajiah. Simulation-based analysis of the use of PCM-wallboards to reduce cooling energy demand and peak-loads in low-rise residential heavyweight buildings in Kuwait. Building Simulation. 2017; 10 (4):481-495.

Chicago/Turabian Style

Nelson Soares; Christoph F. Reinhart; Ali Hajiah. 2017. "Simulation-based analysis of the use of PCM-wallboards to reduce cooling energy demand and peak-loads in low-rise residential heavyweight buildings in Kuwait." Building Simulation 10, no. 4: 481-495.

Journal article
Published: 06 January 2016 in Energy and Buildings
Reads 0
Downloads 0

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.

ACS Style

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 Style

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.

Chicago/Turabian Style

N. 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.

Case report
Published: 07 September 2015 in International Journal of Sustainability in Higher Education
Reads 0
Downloads 0

Purpose – This paper aims to propose an energy efficiency plan (with technical and behavioural improvement measures) for a Portuguese higher education building – the Teaching Building of the Faculty of Economics of the University of Coimbra (FEUC). Design/methodology/approach – The study was developed in the context of both the “Green Campus – Challenge for Energy Efficiency in Higher Education” and the Energy for Sustainability Initiative of the University of Coimbra, Portugal. An energy audit was conducted based on the analysis of the energy consumption profiles. A monitoring campaign was carried out to measure and disaggregate the electricity consumption. The consumption of natural gas and water were also assessed. The building envelope and the heating and lighting systems were also evaluated. Some patterns of energy-environmental behaviours of the academic community were investigated through a Web-based survey. Findings – The energy efficiency plan contemplates short-term tangible/intangible actions. It also considers the investment and payback period of the tangible measures. The implementation of three improvement measures in the lighting system would lead to a consumption reduction of about 26,123 kWh/year, avoiding the emission of 3,704 KgCO2/year, for an initial cost of 9,920 (payback period of 3.7 years). Research limitations/implications – Results are restricted to the case study and there are limitations in their generalisation outside of their context. However, they show some broadly implications and trends that have relevance for the higher education sector. This paper highlights the importance of engaging students, faculty and technical staff for working together on the assessment of the energy efficiency of the buildings where they study and work. Social implications – The higher education sector holds important functions in educating the next generation of professionals for a sustainable culture. The categories of activities described in this paper are good examples of what can be done within the academic community for acting towards sustainability. The results also pointed out that making users aware of their energy consumption is a priority towards the energy efficiency in higher education buildings. Originality/value – Reductions on energy consumption are expected if the energy efficiency plan would be implemented. The results of the behavioural study were presented to the FEUC’s board of directors to be integrated in the “Good Practices Manual on Water and Energy Management”.

ACS Style

Nelson Soares; Luisa Dias Pereira; João Pedro Ferreira; Pedro Conceição; Patricia Pereira da Silva. Energy efficiency of higher education buildings: a case study. International Journal of Sustainability in Higher Education 2015, 16, 669 -691.

AMA Style

Nelson Soares, Luisa Dias Pereira, João Pedro Ferreira, Pedro Conceição, Patricia Pereira da Silva. Energy efficiency of higher education buildings: a case study. International Journal of Sustainability in Higher Education. 2015; 16 (5):669-691.

Chicago/Turabian Style

Nelson Soares; Luisa Dias Pereira; João Pedro Ferreira; Pedro Conceição; Patricia Pereira da Silva. 2015. "Energy efficiency of higher education buildings: a case study." International Journal of Sustainability in Higher Education 16, no. 5: 669-691.

Journal article
Published: 14 January 2015 in Applied Energy
Reads 0
Downloads 0

The heat transfer through a vertical stack of rectangular cavities filled with phase change materials (PCMs) is experimentally analysed in terms of both melting and solidification processes. This paper provides data that are useful for benchmarking and validation of numerical models that account for natural convection in the molten PCM. Two different PCMs are investigated: the free-form PCM-Rubitherm® RT 28 HC; and the microencapsulated PCM-Micronal® DS 5001 X. In terms of practical applications, the main goal is to discuss which PCM type is better for building applications. The time required for the melting and solidification fronts to reach the mid-plane of the cavities is presented as a function of the PCM type. During charging, the control-temperature value on the hot surface of the test-sample and the period of thermal-regulation are investigated. It is shown that the free PCM is preferable for the thermal control of vertical systems as both parameters are improved due to natural convection. The use of microencapsulated PCMs allows accelerating the charging process with almost no thermal stratification. However, in this case the control-temperature effect and the thermal-regulation period are both reduced. Regarding the discharging process, subcooling plays an important role during the solidification of the free PCM and its effect cannot be neglected when modelling.

ACS Style

N. Soares; A.R. Gaspar; P. Santos; J.J. Costa. Experimental study of the heat transfer through a vertical stack of rectangular cavities filled with phase change materials. Applied Energy 2015, 142, 192 -205.

AMA Style

N. Soares, A.R. Gaspar, P. Santos, J.J. Costa. Experimental study of the heat transfer through a vertical stack of rectangular cavities filled with phase change materials. Applied Energy. 2015; 142 ():192-205.

Chicago/Turabian Style

N. Soares; A.R. Gaspar; P. Santos; J.J. Costa. 2015. "Experimental study of the heat transfer through a vertical stack of rectangular cavities filled with phase change materials." Applied Energy 142, no. : 192-205.

Journal article
Published: 02 December 2013 in Energy and Buildings
Reads 0
Downloads 0

This paper evaluates the impact of PCM-drywalls in the annual and monthly heating and cooling energy savings of an air-conditioned lightweight steel-framed (LSF) residential single-zone building, considering real-life conditions and several European climates. A multi-dimensional optimization study is carried out by combining EnergyPlus and GenOpt tools. The CondFD-algorithm is used in EnergyPlus to simulate phase-changes. For the optimization, the PSOCC-algorithm is used considering a set of predefined discrete construction solutions. These variables are related with the thermophysical properties of the PCM (enthalpy-temperature and thermal conductivity-temperature functions), solar absortance of the inner surfaces, thickness and location of the PCM-drywalls. Several parameters are included in the model mainly those related with the air-conditioned set-points, air-infiltration rates, solar gains, internal gains from occupancy, equipment and lighting. Indices of energy savings for heating, cooling and for both heating and cooling are defined to evaluate the energy performance of the PCM-enhanced rooms. Results show that an optimum solution can be found for each climate and that PCMs can contribute for the annual heating and cooling energy savings. PCM-drywalls are particularly suitable for Mediterranean climates, with a promising energy efficiency gain of about 62% for the Csb-Coimbra climate. As for the other climates considered, values of about 10% to 46% were obtained.

ACS Style

N. Soares; Adélio Gaspar; Paulo Santos; José J. Costa. Multi-dimensional optimization of the incorporation of PCM-drywalls in lightweight steel-framed residential buildings in different climates. Energy and Buildings 2013, 70, 411 -421.

AMA Style

N. Soares, Adélio Gaspar, Paulo Santos, José J. Costa. Multi-dimensional optimization of the incorporation of PCM-drywalls in lightweight steel-framed residential buildings in different climates. Energy and Buildings. 2013; 70 ():411-421.

Chicago/Turabian Style

N. Soares; Adélio Gaspar; Paulo Santos; José J. Costa. 2013. "Multi-dimensional optimization of the incorporation of PCM-drywalls in lightweight steel-framed residential buildings in different climates." Energy and Buildings 70, no. : 411-421.

Research article
Published: 31 July 2013 in Journal of Building Physics
Reads 0
Downloads 0

The incorporation of phase change materials in movable structural cells of shading elements associated with southward-facade windows is evaluated in this article. The proposed phase change material–shutter is a thermal energy storage system designed to take advantage of solar energy for winter nighttime indoor heating. A two-dimensional phase-change heat diffusion model based on the enthalpy formulation was considered. The numerical model follows the finite-volume method with a fully implicit formulation and allows the alternating melting and solidification of a phase change material submitted to cyclical thermal boundary conditions. Parametric investigations were carried out about the effects of thermophysical properties of the phase change material and temperature and convection heat transfer boundary conditions on the charge/discharge rates of energy. Due to the low thermal diffusivity of the phase change material, an aluminum fin arrangement was considered as a heat transfer enhancement technique. The distance between fins is directly proportional to the daily energy storage/release capacity of the system. The solar radiation flux has a strong effect on the charging/melting processes during the day. The indoor temperature and the interior convection heat transfer coefficient have a major influence on the discharging/freezing processes during the night. The design of the phase change material–shutter depends strongly on the thermophysical properties of the phase change material and on the interior and exterior boundary conditions considered.

ACS Style

Nelson Soares; José J. Costa; António Samagaio; Romeu Vicente. Numerical evaluation of a phase change material–shutter using solar energy for winter nighttime indoor heating. Journal of Building Physics 2013, 37, 367 -394.

AMA Style

Nelson Soares, José J. Costa, António Samagaio, Romeu Vicente. Numerical evaluation of a phase change material–shutter using solar energy for winter nighttime indoor heating. Journal of Building Physics. 2013; 37 (4):367-394.

Chicago/Turabian Style

Nelson Soares; José J. Costa; António Samagaio; Romeu Vicente. 2013. "Numerical evaluation of a phase change material–shutter using solar energy for winter nighttime indoor heating." Journal of Building Physics 37, no. 4: 367-394.

Review
Published: 08 January 2013 in Energy and Buildings
Reads 0
Downloads 0

This paper aims to explore how and where phase change materials (PCMs) are used in passive latent heat thermal energy storage (LHTES) systems, and to present an overview of how these construction solutions are related to building's energy performance. A survey on research trends are firstly presented followed by the discussion of some physical and theoretical considerations about the building and the potential of integrating PCMs in construction elements. The different types of PCMs and main criteria that govern their selection are reviewed, as well as the main methods to measure PCMs’ thermal properties, and the techniques to incorporate PCMs into building elements. The numerical modeling of heat transfer with phase-change and heat transfer enhanced techniques are discussed, followed by a review of several passive LHTES systems with PCMs. Studies on dynamic simulation of energy in buildings (DSEB) incorporating PCMs are reviewed, mainly those supported by EnergyPlus, ESP-r and TRNSYS software tools. Lifecycle assessments, both environmental and economic are discussed. This review shows that passive construction solutions with PCMs provide the potential for reducing energy consumption for heating and cooling due to the load reduction/shifting, and for increasing indoor thermal comfort due to the reduced indoor temperature fluctuations.

ACS Style

N. Soares; José J. Costa; Adélio Gaspar; Paulo Santos. Review of passive PCM latent heat thermal energy storage systems towards buildings’ energy efficiency. Energy and Buildings 2013, 59, 82 -103.

AMA Style

N. Soares, José J. Costa, Adélio Gaspar, Paulo Santos. Review of passive PCM latent heat thermal energy storage systems towards buildings’ energy efficiency. Energy and Buildings. 2013; 59 ():82-103.

Chicago/Turabian Style

N. Soares; José J. Costa; Adélio Gaspar; Paulo Santos. 2013. "Review of passive PCM latent heat thermal energy storage systems towards buildings’ energy efficiency." Energy and Buildings 59, no. : 82-103.

Journal article
Published: 14 February 2012 in Energy and Buildings
Reads 0
Downloads 0

Presently the essential research trend for sustainable buildings is the use of renewable energy sources and the development of new techniques of energy storage. Phase change materials (PCMs) may store latent heat energy in addition to the typical sensible energy capacity of current building materials, allowing to store significantly more energy during the phase change process (solid to liquid and vice versa). The incorporation of PCMs into building envelope solutions takes advantage of solar energy, contributing to the overall reduction of energy consumption associated to use of the air conditioning systems. This paper presents and discusses research developed in two main components: experimental testing and numerical simulation of a building component with PCM incorporation. The main goal of the experimental testing carried out was to evaluate the effect of the incorporation of PCM macro encapsulated into a typical Portuguese clay brick masonry enclosure wall. It is evaluated the influence of the phase change process of the PCM over the attenuation and time delay of the temperature fluctuations for indoor spaces. The experimental results allowed the calibration and validation of the numerical model, enabling to carry out parametric studies with different PCMs quantity analysing consequent temperature damping and time delay.

ACS Style

Tiago Silva; Romeu Vicente; Nelson Soares; Victor Ferreira. Experimental testing and numerical modelling of masonry wall solution with PCM incorporation: A passive construction solution. Energy and Buildings 2012, 49, 235 -245.

AMA Style

Tiago Silva, Romeu Vicente, Nelson Soares, Victor Ferreira. Experimental testing and numerical modelling of masonry wall solution with PCM incorporation: A passive construction solution. Energy and Buildings. 2012; 49 ():235-245.

Chicago/Turabian Style

Tiago Silva; Romeu Vicente; Nelson Soares; Victor Ferreira. 2012. "Experimental testing and numerical modelling of masonry wall solution with PCM incorporation: A passive construction solution." Energy and Buildings 49, no. : 235-245.