Now showing 1 - 10 of 18
  • Publication
    Extending IFC to support thermal comfort prediction during design
    (European Council on Computing in Construction, 2019-07-12) ; ; ; ; ;
    During the early design stage, designers often rely on general rules of thumb to make critical decisions about the geometry, construction systems and materials without fully evaluating their effects on indoor thermal environment requirements and constraints. Currently, reviewing a design’s sustainability requires designers to spend a significant amount of time manually extracting Thermal Comfort (TC) data from BIMs because of the tedious nature of this task. This paper is motivated by the absence of a standard method and a schema for extracting the necessary data for an automated TC assessment of building designs. The aim is to generate a reusable and retrievable set of Exchange Requirement’s for BIM-based BTCS to facilitate efficient data extraction and exchanges from design models using the IFC file format. Furthermore, we develop an MVD mechanism that provides a structured framework for the definition and exchange of the target data as a step towards standardisation and production of BTCS related information, the results from which contribute to a proposed MVD. The application of the MVD in building design has the potential to improve the early-stage TC assessment of design alternatives. Further, it could reduce the time required to conduct the assessment, increase the reproducibility of results, and formalises the method used.
      807
  • Publication
    Building Manager Requirement Specifications for Efficient Building Operation
    Building management plays a significant role in an organisation aiming to achieve an energy efficient status. In this context, there is growing pressure on building managers to provide not only high-quality building services, but to run and manage buildings as economically and efficiently as possible. As such, management activities require a comprehensive data management system to capture, retrieve and put to optimal use, information related to building performance. In this scenario, Building Information Modelling (BIM) can play the role of data repository and provide easy access to information pertaining to precise equipment locations, equipment affected by a system failure, maintenance history information, etc. Therefore, this paper uses building manager’s business processes and associated information identified throughout the paper to propose a BIM-based building management framework that enables accumulation and management of energy life-cycle data based on Industry Foundations Classes (IFC).
      162
  • Publication
    Requirements for BIM-based thermal comfort analysis
    When designing and creating a working or living space, the provision of thermal comfort for a building’s occupants remains a key objective. However, energy consumption associated with the delivery of indoor environmental conditioning in the commercial building stock is not necessarily translated into improved thermal comfort conditions. When collaborative design utilises Building Information Models (BIMs), much of the data required for thermal comfort analysis is already defined by other project stakeholders. Furthermore, mechanical equipment such as HVAC and lighting fixtures, play a major role in functional performance, resultant thermal comfort and energy consumption. Monitoring building performance and thermal comfort requires additional representative data about indoor environmental conditions and energy consumption. This paper presents a holistic review of the data and information needed for the integration of BIM with thermal comfort modelling for commercial office spaces. Thermal comfort is dependent on multiple factors such as indoor environmental conditions, user behaviour, properties of building materials, etc. For inclusion in the design process this data must first be categorised in a standardised manner. The outputs of this work contribute to a Model View Definition (MVD) for thermal comfort using the IFC standard.
      329
  • Publication
    Development of a Model View Definition (MVD) for thermal comfort analysis in commercial buildings using BIM and EnergyPlus
    (Construction IT Allance of Ireland, 2017-11-24) ; ; ; ;
    Buildings are major consumers of global energy resources. Approximately 80% of the energy used in commercial office spaces, is typically used for maintaining optimal comfort levels through delivery of heating, cooling, ventilating, and lighting. Building Information Modelling (BIM) has seen a significant uptake by designers in pursuit of sustainable building designs. Furthermore, general BIM systems already contain much of the information that can be further reused for additional project tasks such as thermal comfort analysis. Integration and improvement of information flows between BIM and Building Energy Performance Simulation (BEPS) tools has the capacity to help designers assess building performance under various design conditions. In doing so, assessments of building performance and thermal comfort requires additional representative data about indoor environmental conditions and energy consumption. The process of connecting BIM to energy simulation tools, for the explicit purpose of thermal comfort analysis, requires a well-defined Model View Definition (MVD). MVDs define a subset of the Industry Foundation Classes (IFC) schema, which is needed to support a particular business process. This paper develops a MVD for thermal comfort that represents the data needed by building designers or operators to deliver a satisfactory level of thermal comfort in a typical small, single occupant office. The use case consists of a single thermal zone with a HVAC system. The detailed specification for these requirements is based on the IFC data representation. The IfcDoc application tool is used to improve the consistency and define computer-interpretable definition of the MVD. The outputs of this work will allow a standardised exchange of the necessary requirements from BIM to BEPS tools (e.g. EnergyPlus) for thermal comfort analysis.
      294
  • Publication
    Net energy analysis of domestic solar water heating installations in operation
    (Elsevier, 2012-01) ;
    The potential of solar water heating systems to reduce domestic energy use is frequently acknowledged. However there are two factors that are rarely discussed when studying this technology. Firstly the real performance of the installed systems in operation, and secondly a life cycle perspective of its energy use. These two issues are reviewed in this paper, and a field study in Ireland is also presented. In the review, some studies show that measured real performance of domestic solar water heating systems can be lower than expectations. Concerning their life cycle energy performance, existing studies show that the initial energy investment for the systems (their embodied energy) is a small portion of the energy savings over their lifetime with calculation paybacks generally lower than 2 years. On the field study carried in Ireland, representative of a maritime north European climate, the ‘energy payback’ based on the expected energy savings is between 1.2 and 3.5 years, values comparable to previous studies considering the less favourable climate and installation characteristics. However the measured energy savings generally worsened the life cycle energy performance of this technology and thus increased the energy payback period. The study concludes that while there is a real potential for life cycle energy savings through domestic solar water heating installations, devising mechanisms to ensure proper design, installation and operation of systems is essential for this technology.
    Scopus© Citations 41  2833
  • Publication
    The Properties of our Everyday Spectral Microclimate
    (Chartered Institute of Building Services Engineers, 2018-04-13) ; ;
    The CIE illuminant D65 is widely adopted as defining the standard spectral power distribution (SPD) for ‘average’ daylight. Thus daylight indoors is generally assumed to approximate the SPD for D65. The weight of research on the non-visual effects of light now suggests that a key consideration for the long-term health and well-being of occupants should be the amount, duration, timing and, importantly, the spectral profile of illumination received at the eye. Measurements of the SPD of illumination were made at a number of locations outdoor and indoors. In an outdoor environment, the spectral properties of the visible sky dictate the resultant SPD largely irrespective of the surrounding built environment. Only those indoor locations with close proximity to windows exhibit a spectral microclimate comparable to daylight, while all others are dominated by the artificial light sources. Early findings indicate the need to carry out further research to more clearly understand the experienced spectral microclimate.
      133
  • Publication
    Life Cycle Energy Performance: Exploring the limits of passive low energy buildings
    (ASN Events, 2008-09-21) ;
    There is an increasing trend in reducing energy demand of buildings by improving building envelope thermal characteristics. Proven construction examples as used with the German PassivHaus standard achieve substantial reductions on the heating demand compared to mainstream construction, generally by using high levels of insulation together with ensuring excellent air tightness and minimizing of thermal bridges. However, the limits to which levels of insulation in a building can be increased and still represent overall life cycle energy savings are not clear. Particularly for temperate climates, adopting very-high insulation standards can lead to a danger of over specifying construction elements: once we reach certain levels of insulation, any extra material used can have larger energy costs or “embodied energy” than the energy it saves in the life cycle of the building. This paper presents the heating energy use of sample houses in the Irish maritime climate, and analyses the life cycle energy use including the embodied energy of the materials used. A 50-year perspective is presented, and conclusions about the limits to which the heating energy consumption can be lowered by “passive” means on a particular climate are drawn. This paper demonstrates the life-cycle benefits of optimizing the building design ensuring a correct orientation and sizing of the openings, but respecting certain limits when using energy intensive insulation materials.
      305
  • Publication
    A Methodology to Develop Judgment Skills in Sustainable Architectural Education
    (VTT Technical Research Centre of Finland, 2011-10-18) ;
    Students of sustainability, in particular architectural students, are faced with a vast body of published work that forms an important part of their reference library. The idea of the precedent study is, traditionally, central to the education of an architectural student, introducing them to exemplary projects of all types. However many of the buildings published and purporting to be ‘sustainable’ or ‘green’ lack rigorous and impartial review. In the absence of such credible evidence how is a student, or for that matter, their instructor, to know that a particular building is an authentic exemplar upon which to base research or teaching. This paper presents a project and the methodology used by second year architectural students in University College Dublin designed to instil a strong sense of discernment in the student, developing critical and research skills that enable them to differentiate between an authentic sustainable exemplar and one over which there may be doubt. The project first asked each student to arrive at their own definition of sustainable architecture. This was then tested by applying it to three ‘sustainable’ projects of their own choice. They were then asked to choose the most credible of those three and apply a specifically developed environmental rating system, supplied to them, against which to assess their chosen exemplar. The objective and result of the project was to develop within each student the ability to research authoritative information online, in books and journals and to use this to support and argue for authentic exemplars of sustainable practices in architectural design. The highest rated case studies were then available to the whole class as genuine examples of the highest international standard in sustainable architectural practice. The best five exemplars of the class were then published in a national sustainable construction magazine, Construct Ireland, along with the methodology developed for the project and used in their assessment.
      748
  • Publication
    Energy ratings based on measured energy consumption : a practical approach for implementation of EPBD and identification of high-energy use buildings.
    (University of Minho, 2007-09-12) ; ;
    Article 7 of the EU Energy Performance of Buildings Directive requires Member States to implement energy certification for buildings, and particularly for large public buildings, requires an energy certificate to be displayed in public. This paper outlines a simplified procedure for the certification of existing public buildings based on measured energy consumption, which is applicable even in countries where information on the building stock is not currently available. Energy consumption data collected for a number of buildings is used to develop energy benchmarks for typical and good practice energy performance. The rating procedure is based on a comparison between the energy consumption of each building and the derived benchmarks; a process that is illustrated in a sample of 88 Irish primary schools. The paper concludes with a discussion on the next steps to a more detailed measured rating procedure.
      267
  • Publication
    Requirements specification to support BIM-based Thermal Comfort analysis
    Traditionally and during a building's operation, thermal comfort levels are often evaluated using equipment that is expensive to purchase and maintain. Through advanced technologies, Building Information Model (BIM) and energy simulation tools, thermal comfort and its impacts can be evaluated at the conceptual and early design stages. The development of Building Energy Performance Simulation (BEPS) tools, through the implementation of BIM, will provide design teams with rich, comprehensive data to evaluate indoor thermal conditions in order to provide acceptable comfort levels. Current energy simulation models focus on entering data manually, increasing time and cost. BIM-based energy and thermal comfort analysis provides designers with the means to explore a variety of design alternatives, as well as avoiding the time-consuming process of re-entering all of the building's geometry and HVAC specifications to perform an analysis. However, integrating BEPS with BIM-based building design tools is still limited, with one of the key obstacles being the lack of standardised methods for information exchange between the two domains. To address the needs and bridge the gaps, this paper aims to improve the information exchange process by describing data and information needed to perform thermal comfort simulation using a standardised format in order to develop a Model View Definition (MVD) for thermal comfort. This approach represents the data needed by building designers or operators to provide an acceptable level of thermal comfort in a typical small, single occupant office. Through analysis of the performance of the proposed approach, this work provides a standardised exchange of data from BIM to BEPS tools, such as EnergyPlus, using the Industry Foundation Classes (IFC) standard.
      235