Now showing 1 - 6 of 6
  • Publication
    Operational and embodied energy analysis of 8 single-occupant dwellings retrofit to nZEB standard
    In line with the Energy Performance of Buildings Directive, Irish dwellings are being retrofit to near Zero Energy Building (nZEB) standards - with a number of the deep energy retrofits classified as A-rated. As a result of the low operational energy, the embodied energy share of an nZEB's life cycle energy is significantly increased. Therefore, to obtain a holistic picture of the change in energy profile of buildings, the embodied energy of the material added to achieve that low performance should also be taken into account. This paper presents results from a case study of 8 single-occupant terrace bungalows retrofit to nZEB standard. The pre- and post-retrofit operational performance is first estimated using the Irish Dwelling Energy Assessment Procedure (DEAP). The post-retrofit operational performance of the space heating and domestic hot water heating system is also measured over a year. The embodied energy is estimated by way of embodied carbon/energy calculations. Monitored results of the 8 similar buildings exhibit a wide variance of operational energy consumption while the embodied energy is (by nature of the calculation) consistent. The average estimated primary energy requirement for the buildings was 674 kWh/(m2ᐧyear) pre-retrofit and 38 kWh/(m2ᐧyear) post-retrofit while the average measured primary energy requirement for space heating and hot water alone was 119 kWh/(m2ᐧyear) – ranging from 74 to 167 kWh/(m2ᐧyear) for the 8 houses. The embodied energy of the materials and technologies used to retrofit the buildings was 676 kWh/m2. Despite the building performing worse than expected, desirable primary energy and carbon paybacks of 2.0 and 6.1 years were achieved respectively. These positive payback periods are largely due to the very poor operational performance of the buildings pre-retrofit.
      115
  • Publication
    Recorded energy consumption of nZEB dwellings and corresponding interior temperatures: Initial results from the Irish nZEB101 project
    (University of A Coruña & Asoc. PLEA 2020 Planning Post Carbon Cities, 2020-09-03) ; ; ; ;
    Ireland is mandating the unprecedented mass market deployment of low-energy dwellings via the near Zero Energy Buildings (nZEB) standard, from 1 January 2021 due to the EU wide Energy Performance of Buildings Directive (EPBD). This is among the first academic papers to provide recorded energy and temperature data for nZEB compliant dwellings in Ireland. It reports on initial results of the www.nZEB101.ie Post Occupancy Evaluation project, the objective of which is to uncover key nZEB design and operations lessons, to aid the next iteration of the country's building regulations. This paper reports on the analysis of winter temperatures and the energy consumption of 17 nZEB compliant dwellings, each of which have been monitored for at least a 12 month period. While analysis of further properties is needed to further validate the findings, key findings to date include significantly higher than expected interior temperatures and energy consumption, and a usage profile which is significantly different from the assumptions in the DEAP National energy rating software.
      99
  • Publication
    Framework for Bridge Inspection with Laser Scanning
    For the last two decades, a significant amount research has been developed for collecting data for bridge inspection. Yet, visual investigation with an on-site inspector remains the predominant method; however is the highly subjective and time consuming. Alternatively, terrestrial laser scanner (TLS) can acquire surface details of structures quickly and accurately and is, thus, an emerging means to overcome the shortcomings of direct visual inspection. This paper presents a framework of bridge inspection using TLS data, where a strategy of processing TLS data for deformation measurement, damage detection, and reconstruction of three dimension (3D) as-built models are explored. Demonstration of the application in bridge inspection is also provided.
      755
  • Publication
    Lateral image degradation in terrestrial laser scanning
    (International Association of Bridge and Structural Engineers, 2009-05) ; ; ; ; ;
    The use of aerial laser scanning to detect change in infrastructure and buildings after major disasters has become increasingly common in recent years to help prioritize interventions. More recent efforts are being invested to apply laser scanning in the assessment and structural health monitoring of buildings to simplify and quicken building damage surveys by the automatic detection of defects and deformations. Technology application must, however, be done in cognizance of equipment constraints regarding scan angle, sampling size, and beam width. This article reports a series of laboratory and field experiments designed to begin to quantify and minimise the possible errors for effective defect detection via terrestrial laser scanning during surveying. Varying geometric positions that cause either over- or under-prediction of crack thickness and length as a function of both standoff distance and angle of obliquity between the scanner and the defect are presented. These may over-predict horizontal crack thickness by 15 mm and failing to detect others. To help minimise such errors, a standoff distance of 12–15 m with a maximum obliquity of 45˚ between the scanner and target object are recommended.
      880Scopus© Citations 23
  • Publication
    Viability assessment of terrestrial LiDAR for retaining wall monitoring
    (American Society of Civil Engineering (ASCE), 2008-03) ;
    The decreased cost and increased processing speed for terrestrial laser scanners have made this remote sensing procedure much more attractive. The approach has two major advantages over traditional surveying: (1) a registration of the survey instrument independent of any physical benchmarks. Thus, if the entire area is experiencing subsidence, the quality of the final results will not be compromised as they will be absolute measurements, as opposed to relative ones because they are based on a global positioning registration; (2) the ability of the technologies to highlight cracks in masonry. Unfortunately, despite major advances in the equipment and software, the technology is arguably not fully ready for the task of automated retaining wall monitoring. This paper will outline the challenges that remain with respect to registration and displacement monitoring.
      1468Scopus© Citations 8