Now showing 1 - 10 of 18
  • 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.
      308
  • Publication
    Optimising Life Cycle Energy Performance of Housing: The Value of Occupancy Control
    (Les Presses de l'Université Laval, 2009-06-22) ;
    There is a trend towards reducing heating and cooling requirements of buildings by using high levels of insulation, minimizing thermal bridging, and ensuring excellent air tightness, together with the operation of efficient mechanical ventilation heat recovery (MVHR) systems. In temperate climates, this approach has already raised questions about potential risks of over-specifying some construction elements and installations. This study argues that in maritime climates, appropriate building design with occupant controlled natural ventilation could provide an optimum life cycle energy performance. A heating demand analysis of a sample case study house with MVHR and of the same case study with naturally ventilation is presented, testing different levels of insulation for each case. Embodied energy data of the additional envelope insulation and the MVHR system is added to the operational energy , and the options are compared from a life cycle perspective.
      319
  • 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).
      164
  • Publication
    Sensitivity analysis of a maritime located night ventilated library building
    (National Technical University of Athena, 2005-05-19) ; ;
    This paper assesses the role of design and operational parameters in a night ventilated library building that has been designed for a maritime type climate. The design rationale behind the building is elaborated and decisions associated with the various design parameters discussed. A model of the building is created using the ESPr simulation program which after experimental validation is used to carry out parametric and sensitivity studies on the building. The role of different building design and operational parameters are examined including building mass, external gains, internal gains, ventilation duration, ventilation rates, as well as ventilation operational strategies.
      490
  • Publication
    The transparency and repeatability of building energy performance certification
    The European Union’s (EU) Energy Performance of Buildings Directive (EPBD) aims to increase the energy performance (EP) of buildings by requiring EU Member States to develop an EP calculation methodology and to certify the EP of their buildings. Dynamic simulation offers an important means of developing accurate EP ratings. However, its value may be undermined due to the difficulty in obtaining transparent and repeatable input data on existing buildings. Using the EnergyPlus simulation engine and a DesignBuilder interface this research investigated the impact of this difficulty on the EP grade of four primary school buildings. Survey and on-site refinement phases enabled base case buildings to be modelled, a standard activity schedule to be developed and the lack of transparency and repeatability in the specification of the infiltration air change rate (ACH), the boiler efficiency and glazing parameters to be seen. Using parametric sensitivity analysis in combination with the draft European standard for the energy certification of buildings, prEN15217:2005, it was found that variations in the specification of these parameters could lead to up to two grade changes for boiler efficiency and ACH, one grade change due to the sensitivity of the glazing parameter and three grade changes should their affect be combined. Although repeatability and transparency can be improved through careful training of building EP assessors and the awareness of a particular parameters affect on an EP grade, it will be difficult to ensure repeatability and transparency using a dynamic simulation EP grading methodology if experimental testing is not utilised.
      208
  • Publication
    Whole-Sky Luminance Maps from Calibrated Digital Photography
    (International Solar Energy Society, 2006) ; ;
    Sky luminance is an essential component in assessing the appearance and performance of internal spaces which are highly sensitive to the often dynamic luminance of the visible sector of the sky. Therefore, whole sky luminance distributions representative of real-sky sectoral dynamics over short time intervals are required. A modified scientific-grade digital camera was used to measure whole-sky luminance distributions of various sky conditions. Results showed acceptable correlation between the measured and calculated results for overcast and clear skies demonstrating the viability of using hemispherical digital photography for mapping whole-sky luminance distributions. However, intermediate skies showed distinct sectoral variations and dynamics supporting the argument for more accurate and respresentative luminance distribution data.
      795
  • Publication
    Sensitivity Analysis of the EPBD Energy Performance Grading of Buildings
    (Heliotopos Conferences, 2007-09) ; ;
    The Energy Performance of Buildings Directive (EPBD) obligates EU member states to develop a reliable methodology capable of calculating and certifying the energy performance (EP) of their building stock. In this paper, studies on a series of school buildings, based on Standard prEN15217:2005, consider the impact that a lack of transparency in the data gathering procedure might have on the repeatability of the EP grades. The results showed that variations in EP grades ranging from 0.06 to 1.06 EP grades were possible. The sensitivity of prEN15217: 2005 to variations of input parameters was also investigated and was found to be most sensitive to air change rates and boiler efficiency with grade changes of up to 1.5 grades possible. It was also found that prEN15217:2005 was not heavily influenced by improvements in roof and window specifications.
      351
  • 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.
      750
  • 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.
      332
  • 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.
      237