876 resultados para Buildings maintenance
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Contributed to: "Measuring the Changes": 13th FIG International Symposium on Deformation Measurements and Analysis; 4th IAG Symposium on Geodesy for Geotechnical and Structural Enginering (Lisbon, Portugal, May 12-15, 2008).
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Thus far most studies of operational energy use of buildings fail to take a longitudinal view, or in other words, do not take into account how operational energy use changes during the lifetime of a building. However, such a view is important when predicting the impact of climate change, or for long term energy accounting purposes. This article presents an approach to deliver a longitudinal prediction of operational energy use. The work is based on the review of deterioration in thermal performance, building maintenance effects, and future climate change. The key issues are to estimate the service life expectancy and thermal performance degradation of building components while building maintenance and changing weather conditions are considered at the same time. Two examples are presented to demonstrate the application of the deterministic and stochastic approaches, respectively. The work concludes that longitudinal prediction of operational energy use is feasible, but the prediction will depend largely on the availability of extensive and reliable monitoring data. This premise is not met in most current buildings. © 2011 Elsevier Ltd.
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Most studies on the environmental performance of buildings focus on energy demand and associated greenhouse gas emissions. They often neglect to consider the range of other resource demands and environmental impacts associated with buildings, including water. Studies that assess water use in buildings typically consider only operational water, which excludes the embodied water in building materials or the water associated with the mobility of building occupants. A new framework is presented that quantifies water requirements at the building scale (i.e. the embodied and operational water of the building as well as its maintenance and refurbishment) and at the city scale (i.e. the embodied water of nearby infrastructures such as roads, gas distribution and others) and the transport-related indirect water use of building occupants. A case study house located in Melbourne, Australia, is analysed using the new framework. The results show that each of the embodied, operational and transport requirements is nearly equally important. By integrating these three water requirements, the developed framework provides architects, building designers, planners and decision-makers with a powerful means to understand and effectively reduce the overall water use and associated environmental impacts of residential buildings.
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Following automation of lighthouses around the coastline of Ireland, reports of accelerated deterioration of interior granite stonework have increased significantly with an associated deterioration in the historic structure and rise in related maintenance costs. Decay of granite stone- work primarily occurs through granular disintegration with the effective grusification of granite surfaces. A decay gradient exists within the towers whereby the condition of granite in the lower levels is much worse than elsewhere. The lower tower levels are also regions with highest rela- tive humidity values and greatest salt concentrations. Data indicate that post-automation decay may have been trig- gered by a change in micro-environmental conditions within the towers associated with increased episodes of condensation on stone surfaces. This in turn appears to have facilitated deposition and accumulation of hygro- scopic salts (e.g. NaCl) giving rise to widespread evidence of deliquescence in the lower tower levels. Evidence indicates that the main factors contributing to accelerated deterioration of interior granite stonework are changes in micro-environmental conditions, salt weathering, chemical weathering through the corrosive effect of strongly alkaline conditions on alumino-silicate minerals within the granite and finally, the mica-rich characteristics of the granite itself which increases its structural and chemical susceptibility to subaerial weathering processes by creating points of weakness within the granite. This case study demonstrates how seemingly minor changes in micro-environmental conditions can unintentionally trigger the rapid and extensive deterioration of a previously stable rock type and threaten the long-term future of nationally iconic opera- tional historic structures.
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This talk addresses the problem of controlling a heating ventilating and air conditioning system with the purpose of achieving a desired thermal comfort level and energy savings. The formulation uses the thermal comfort, assessed using the predicted mean vote (PMV) index, as a restriction and minimises the energy spent to comply with it. This results in the maintenance of thermal comfort and on the minimisation of energy, which in most operating conditions are conflicting goals requiring some sort of optimisation method to find appropriate solutions over time. In this work a discrete model based predictive control methodology is applied to the problem. It consists of three major components: the predictive models, implemented by radial basis function neural networks identifed by means of a multi-objective genetic algorithm [1]; the cost function that will be optimised to minimise energy consumption and provide adequate thermal comfort; and finally the optimisation method, in this case a discrete branch and bound approach. Each component will be described, with a special emphasis on a fast and accurate computation of the PMV indices [2]. Experimental results obtained within different rooms in a building of the University of Algarve will be presented, both in summer [3] and winter [4] conditions, demonstrating the feasibility and performance of the approach. Energy savings resulting from the application of the method are estimated to be greater than 50%.
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A very important part of the globally produced energy is consumed in buildings, being an important share frequently used in the HVAC systems. These ones are increasing both in performance and in complexity, taking advantage from the use of the recent advances in mechanical and power electronic devices, particularly in the speed variation field. However the improved efficiency only occurs while the HVAC unit is working in the conditions specified by the manufacturer, otherwise the energy consumption raises to values considerably higher than the nominal ones. The adequate maintenance enforces the system to run on its nominal performance and the contrary has undesirable impact both in the performance and in the system expected life time. Therefore, HVAC field maintenance assumes a very important role in the global building sustainability concept. This work presents some results of an incorrect use of HVAC and the associated electric energy overconsumption that can assume values 50% higher than those that occur when the installation is operated according to the adequate maintenance plan.
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Modern buildings are designed to enhance the match between environment, spaces and the people carrying out work, so that the well-being and the performance of the occupants are all in harmony. Building services are systems that facilitate a healthy working environment within which workers productivity can be optimised in the buildings. However, the maintenance of these services is fraught with problems that may contribute to up to 50% of the total life cycle cost of the building. Maintenance support is one area which is not usually designed into the system as this is not common practice in the services industry. The other areas of shortfall for future designs are; client requirements, commissioning, facilities management data and post occupancy evaluation feedback which needs to be adequately planned to capture and document this information for use in future designs. At the University of Reading an integrated approach has been developed to assemble the multitude of aspects inherent in this field. The means records required and measured achievements for the benefit of both building owners and practitioners. This integrated approach can be represented in a Through Life Business Model (TLBM) format using the concept of Integrated Logistic Support (ILS). The prototype TLBM developed utilises the tailored tools and techniques of ILS for building services. This TLBM approach will facilitate the successful development of a databank that would be invaluable in capturing essential data (e.g. reliability of components) for enhancing future building services designs, life cycle costing and decision making by practitioners, in particular facilities managers.
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Purpose – The purpose of this paper is to present the findings and lessons learned from three case studies conducted for facilities located in California, North America. The findings aim to focus on energy and maintenance management practices and the interdependent link between energy and maintenance. Design/methodology/approach – The research is based on a positivist epistemological philosophical approach informed by action research. The research cycle was completed for each case study. A case study report was provided to each facility management team to foster collaboration with the researcher and to document case study process and results. Findings – Composite findings of the case studies include: there is an interdependent link between energy and maintenance management; reactive maintenance and energy management methods are commonly used; and more proactively operated and managed buildings require the interdependent link between energy maintenance management to be better understood. Research limitations/implications – The three case studies were located in California. Although the case study results can be generalized, determination of how to generalize and apply the results to commercial buildings outside of the USA is beyond the scope of this paper. Practical implications – Detailed discussion of the needs of the three facility management teams are discussed by identifying a current challenge, developing a solution and documenting lessons learned using the research cycle. Originality/value – The paper seeks to demonstrate the interdependencies of energy and maintenance management, two topics which are often researched interdependently. Additionally, the paper provides insight about maintenance management, a topic often cited as being under researched.
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143, 147, omitted in numbering.
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Mode of access: Internet.
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"ILENR/BE-87/01."
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Issued Feb. 1977.
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Includes index.
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Includes index.