Design and Manufacture of a precast PCM enhanced concrete cladding panel for full scale performance monitoring

The overall aim of this study is to develop innovative precast cladding panels for the renovation of Europe’s existing building stock thereby improving their energy performance. Using the mass of a building to store heat and/or cold can reduce the demand on the auxiliary heating and/or cooling systems and hence reduce the overall energy demand of the building. Previous laboratory research has shown that the incorporation of phase change materials (PCMs) into concrete enhances its thermal storage capacity by up to 50%. However in a real application where a PCM-concrete composite material is used in a building to store thermal energy, the effectiveness of the PCM depends on many variables including the form of construction and local climate conditions. In this research study a precast cladding panel formed with PCM enhanced concrete has been developed and manufactured. In order to observe the performance of the PCM-concrete composite panels in a full scale scenario, three demonstration huts have been constructed and instrumented to record internal thermal behaviour. Monitoring of the data is ongoing and shows that the effectiveness of the PCM varies with the seasons. Data recorded during the summer period highlighted that the internal temperature may not drop low enough during the night to solidify the PCM and discharge the stored heat. A further test in which passive ventilation was provided during the night proved to be an effective method of addressing this issue. It is expected that this long term study will enable recommendations to be made on the seasonal benefits of using PCM-concrete to enhance the energy performance of buildings located in climate conditions similar to Ireland. The results of the data analysis will inform a refinement of the panel design prior to installing the panels at a school in the UK which currently has an overheating problem

Assessment of Two Methods of Enhancing Thermal Mass Performance of Concrete Through the Incorporation of Phase-Change Materials

According to the IEA Technology Roadmap on Energy Efficient Building Envelopes, buildings are responsible for more than one third of global energy consumption, with space heating and cooling consuming 33% of this energy, and increasing to 50% in cold climates. Using the mass of a building to store heat and/ or cold can reduce the demand on the auxillary heating and/or cooling systems and hence reduce the overall energy demand of the building. In this study the thermal storage capacity of concrete was actively enhanced by integrating phase-change materials (PCMs) which provide a high latent heat storage capacity. Two methods of incorporating PCMs into concrete were used to form PCM/concrete composite panels. The first type of panel was formed by adding microencapsulated paraffin to fresh concrete during the mixing process. The second panel was formed by vacuum impregnating butyl stearate into lightweight aggregate which was then included in the concrete mix. The aim of the study was to compare the thermal behaviour of both PCM/concrete composite panels to a control concrete panel and to evaluate which method of PCM incorporation is the most effective at improving thermal mass characteristics in the context of a thermal energy storage system for space heating/cooling in a building. The panels containing PCM displayed significantly greater thermal storage capacity, despite having reduced thermal conductivity and density. The study concluded that the panel containing lightweight aggregate/PCM composite is more effective at providing additional thermal storage, particularly within the first 100mm of depth of an element of structure

Problem-Based Learning: Student Perceptions of its Value in Developing Professional Skills for Engineering Practice

This study explores students’ perceptions of the effectiveness of a Problem-Based Learning (PBL) design project, taken as part of a first-year engineering module, in developing professional skills needed for engineering practice. Students completed surveys before and after the PBL group project, and produced personal reflections on the process. The closed survey questions were analysed quantitatively and the main themes from the reflections outlined using General Inductive Analysis. Students rated themselves as having improved across a range of professional skills as a result of the project, with particular emphasis on teamwork, communication skills, understanding of the design process and self-directed learning. In addition, they highlighted improved confidence, as well as new friendships they developed, an important element of a module like this as they transition from secondary to higher education. They were particularly positive about the scaffolded approach taken within the PBL project in terms of its contribution to their learning

Thermal Mass Behaviour of Concrete Panels Incorporating Phase Change Materials

Phase Change Materials (PCM) have been incorporated into a range of building envelope materials with varied success. This study investigates two different methods of combining concrete and phase change materials to form PCM/concrete composite panels. The first method involves adding microencapsulated paraffin to fresh concrete during the mixing process. The second method involves vacuum impregnating butyl stearate into lightweight aggregate which is then included in the concrete mix design. The primary aim of the study is to determine which method is the most effective way to improve the thermal mass characteristics of a concrete panel in the context of a thermal energy storage system for space heating in a building. The study observes the rate at which the panels absorb and emit heat, ie, the heat flux, and also how the heat flux changes throughout the depth of the panel. The panels are heated in a controlled environment provided by a specifically designed light box. Radiation is used as the heat transfer mechanism. Surface and internal temperatures of the panels are recorded during heating and cooling periods. The data recorded, together with the determined densities and thermal conductivities, are used to compare the thermal mass behaviour of each type of panel and to determine the influence that the method of incorporating a phase change material into a concrete panel has on the effectiveness of the PCM to improve the thermal mass characteristics of the concrete panel. The study highlighted the complexity of thermal behaviour of PCM/concrete composites. The panels containing PCM displayed significantly greater thermal storage capacity despite having reduced thermal conductivity and density. The study concluded that the panel containing lightweight aggregate/PCM composite is more effective at providing additional thermal storage particularly within the first 100mm of depth of an element of structure

Thermal Mass Performance of Concrete Panels Incorporated with Phase Change Materials

Using the mass of a building as a thermal storage system can reduce the demand on the auxiliary heating and cooling systems of the building. Concrete combines a high specific heat capacity with a thermal conductivity that is appropriate for the diurnal heating and cooling cycle of buildings. The heat storage capacity of concrete can be enhanced by adding phase change materials (PCMs) which provide a high latent heat storage capacity. However the addition of PCM to concrete reduces the conductivity of the concrete which may affect the ability of a PCM-concrete panel to absorb and release heat within the desired time period. In this study two different methods of combining concrete and phase change materials were used to form PCM/concrete composite panels. The panels were exposed to radiative heat energy in a controlled environment for a specified time period during which the surface and internal temperatures of the panel were recorded. The temperature data together with the measured density and thermal conductivity was used to evaluate and compare the thermal mass behaviour of each type of PCM/concrete composite material. The addition of PCM to the concrete significantly increased the overall thermal storage capacity of the concrete despite reducing the density and thermal conductivity of the concrete

Influence of Ground Granulated Blastfurnace Slag on the Thermal Properties of PCM-concrete Composite Panels

The thermal mass of concrete within a building can be used as an energy storage system and hence reduce the demand on the auxiliary heating and cooling systems in the building. The heat storage capacity of concrete can be enhanced by adding phase change materials (PCMs) which provide a high latent heat storage capacity. However the addition of PCM to concrete reduces the conductivity of the concrete due to the low conductivity of the PCMs. This hinders the efficient utilisation of the additional heat storage capacity provided by the PCM. It is generally understood that the use of ground granulated blastfurnace slag (GGBS) as a partial cement replacement results in a denser cement paste which, for a given aggregate type, increases the conductivity of the concrete. The aim of this study was to determine if the use of GGBS influences the thermal mass behaviour of a PCM-concrete. Two types of PCM-concrete panels were manufactured. Firstly microencapsulated paraffin was added to fresh concrete during the mixing process. Secondly butyl stearate was vacuum impregnated into lightweight aggregate which was then included in the concrete mix. Half of the samples contained 50% GGBS cement replacement and consequently the effect of GGBS on the thermal performance is reporte

Students’ Experiences Of Reflecting On Their Development Of Professional Skills In An Engineering Programme.

Engineers play a central role in addressing the challenges which face society, and recent literature highlights the need for emphasis on the development of professional skills in engineering programmes. This paper describes the outcomes of a study which investigated students’ experiences of reflecting on the development of their professional skills using an ePortfolio in a pilot project. A focus group was used to capture students’ experiences of the reflection process and the use of the ePortfolio. Transcripts were analysed thematically to draw out the key experiences and to provide feed-forward advice for the next iteration of the project. The findings show that students need support in the reflection process, and clearer signposting between each skill and the modules relevant to their development. Students also found it difficult to ascertain their competency levels and felt that industry experience was needed to help score themselves accurately. Feed-forward advice included incorporating an ePortfolio throughout all years of the programme which would track their improvement in a range of skills, and providing a rubric to help assess their competency. The outcome of this study can be used by educators who wish to incorporate a professional skills ePortfolio in their engineering programmes

THE IDENTIFICATION OF FUTURE PROFESSIONAL SKILLS FOR THE GRADUATE STRUCTURAL ENGINEER AND THE CO-CREATION OF THEIR DEFINITIONS.

Employers recognise that the future is changing and as such the structural engineer’s role is changing along with the skill set required. The skills gap has been acknowledged yet there is no consensus on which skills are most important for these engineers. This research presents the outcome of a project which proposes future professional skills needs for the structural engineer and the co-creation of their definitions. A review of the most recent relevant literature alongside chartership requirements of the Institution of Structural Engineers (IStructE) and Engineers Ireland (EI), as well as consideration of three seminal consultation and analysis reports on the future skills in the sector, led to the identification of 7 skills. These are the traditional, though evolving skills related to communication, technical ability, management and engineering practice as well as emerging skills related to sustainability, technology and digitisation and society. It is accepted, however, that there may be different conceptions of each term, therefore, the presented research describes the co-creation of definitions for each of these skills with undergraduate structural engineering students. The work describes how focus groups were used to engage students in a conversation around the meaning and importance of each skill resulting in specific action orientated definitions for each skill. These definitions will then be used in the next phases of the project which engage the same students in a reflective e-portfolio exercise and structural engineering educators in a review of the programme outcomes in relation to such skills

Thermal Energy Storage in Building Integrated Thermal Systems: A Review. Part 2. Integration as Passive System

Energy consumption trends in residential and commercial buildings show a significant increase in recent decades. One of the key points for reducing energy consumption in buildings is to decrease the energy demand. Buildings envelopes are not just a structure they also provide protection from outdoor weather conditions always taking into account the local climate. Thermal energy storage has been used and applied to the building structure by taking advantage of sensible heat storage of materials with high thermal mass. But in recent years, researchers have focused their studies on the implementation of latent heat storage materials that if well incorporated could have high potential in energy demand reduction without occupying the space required by sensible storage. The aim of this study is to review the thermal energy storage passive systems that have been integrated in building components such as walls, ceilings or floors, and to classify them depending on their component integration