Passive solar systems for heating, daylighting and ventilation for rooms without an equator-facing facade

Spaces without northerly orientations have an impact on the ‘energy behaviour’ of a building. This paper outlines possible energy savings and better performance achieved by different zenithal solar passive strategies (skylights, roof monitors and clerestory roof windows) and element arrangements across the roof in zones of cold to temperate climates typical of the central and central-southern Argentina. Analyses were undertaken considering daylighting, thermal and ventilation performances of the different strategies. The results indicate that heating,ventilation and lighting loads in spaces without an equator-facing facade can be significantly reduced by implementing solar passive strategies. In the thermal aspect, the solar saving fraction reached for the different strategies were averaged 43.16% for clerestories, 41.4% for roof monitors and 38.86% for skylights for a glass area of 9% to the floor area. The results also indicate average illuminance levels above 500 lux for the different clerestory and monitor arrangements, uniformity ratios of 0.66–0.82 for the most distributed arrangements and day-lighting factors between 11.78 and 20.30% for clear sky conditions, depending on the strategy. In addition, minimum air changes rates of 4 were reached for the most extreme conditions.

Developing a vision for an nD modelling tool

The design of a building is a complicated process, having to formulate diverse components through unique tasks involving different personalities and organisations in order to satisfy multi-faceted client requirements. To do this successfully, the project team must encapsulate an integrated design that accommodates various social, economic and legislative factors. Therefore, in this era of increasing global competition integrated design has been increasingly recognised as a solution to deliver value to clients.----- The ‘From 3D to nD modelling’ project at the University of Salford aims to support integrated design; to enable and equip the design and construction industry with a tool that allows users to create, share, contemplate and apply knowledge from multiple perspectives of user requirements (accessibility, maintainability, sustainability, acoustics, crime, energy simulation, scheduling, costing etc.). Thus taking the concept of 3-dimensional computer modelling of the built environment to an almost infinite number of dimensions, to cope with whole-life construction and asset management issues in the design of modern buildings. This paper reports on the development of a vision for how integrated environments that will allow nD-enabled construction and asset management to be undertaken. The project is funded by a four-year platform grant from the Engineering and Physical Sciences Research Council (EPSRC) in the UK; thus awarded to a multi-disciplinary research team, to enable flexibility in the research strategy and to produce leading innovation. This paper reports on the development of a business process and IT vision for how integrated environments will allow nD-enabled construction and asset management to be undertaken. It further develops many of the key issues of a future vision arising from previous CIB W78 conferences.

An evolutionary framework for enhancing design

A computational framework for enhancing design in an evolutionary approach with a dynamic hierarchical structure is presented in this paper. This framework can be used as an evolutionary kernel for building computer-supported design systems. It provides computational components for generating, adapting and exploring alternative design solutions at multiple levels of abstraction with hierarchically structured design representations. In this paper, preliminary experimental results of using this framework in several design applications are presented.

Positive development

net sustainability. At best they reduce relative resource consumption. They still consume vast quantities of materials, energy, water and ecosystems during construction. Moreover, green buildings replace land and ecosystems with structures that, at the very best, only 'mimic' ecosystems<'). Mimicking nature is little compensation when we have lost a third of species that are integral parts of our life support system. Already, development has exceeded the Earth's ecological carrying capacity, so even 'restorative' design is not enough. Urban areas must be retrofitted to increase net bioregional carrying capacity - just to support existing or reduced population levels in cities. The eco-retrofitting of our built environment is therefore an essential precondition of achieving a sustainable society. But we need to eco-retrofit cities in ways that increase net sustainability, not just relative efficiency.

Challenging 'best practice' subtropical design

Genuine sustainability would require that urban development provide net positive social and ecological gains to compensate for previous lost natural capital and carrying capacity. Thus far, green buildings do not contribute to net sustainability. While they reduce relative resource consumption, they consume vast quantities of materials, energy and water.i Moreover, they replace land and ecosystems with structures that, at best, ‘mimic’ ecosystems. Elsewhere, the author has proposed a‘sustainability standard’, where development would leave the ecology, as well as society, better off after construction than before.ii To meet this standard, a development would need to add natural and social capital beyond what existed prior to development. Positive DesignTM or Positive DevelopmentTM is that which expands both the ecological base (life support system) and the public estate (equitable access to means of survival). How to achieve this is discussed in Positive Development (Birkeland 2008). This paper examines how net positive gains can be achieved in a ubtropical as well as temperate environment.

Sound radiation characteristics of a box-type structure

The finite element and boundary element methods are employed in this study to investigate the sound radiation characteristics of a box-type structure. It has been shown [T.R. Lin, J. Pan, Vibration characteristics of a box-type structure, Journal of Vibration and Acoustics, Transactions of ASME 131 (2009) 031004-1–031004-9] that modes of natural vibration of a box-type structure can be classified into six groups according to the symmetry properties of the three panel pairs forming the box. In this paper, we demonstrate that such properties also reveal information about sound radiation effectiveness of each group of modes. The changes of radiation efficiencies and directivity patterns with the wavenumber ratio (the ratio between the acoustic and the plate bending wavenumbers) are examined for typical modes from each group. Similar characteristics of modal radiation efficiencies between a box structure and a corresponding simply supported panel are observed. The change of sound radiation patterns as a function of the wavenumber ratio is also illustrated. It is found that the sound radiation directivity of each box mode can be correlated to that of elementary sound sources (monopole, dipole, etc.) at frequencies well below the critical frequency of the plates of the box. The sound radiation pattern on the box surface also closely related to the vibration amplitude distribution of the box structure at frequencies above the critical frequency. In the medium frequency range, the radiated sound field is dominated by the edge vibration pattern of the box. The radiation efficiency of all box modes reaches a peak at frequencies above the critical frequency, and gradually approaches unity at higher frequencies.

Improving daylighting performance of mirrored light pipes

This paper assesses and compares the performances of two daylight collection strategies, one passive and one active, for large-scale mirrored light pipes (MLP) illuminating deep plan buildings. Both strategies use laser cut panels (LCP) as the main component of the collection system. The passive system comprises LCPs in pyramid form, whereas the active system uses a tiled LCP on a simple rotation mechanism that rotates 360° in 24 hours. Performance is assessed using scale model testing under sunny sky conditions and mathematical modelling. Results show average illuminance levels for the pyramid LCP ranging from 50 to 250 lux and 150 to 200 lux for the rotating LCPs. Both systems improve the performance of a MLP. The pyramid LCP increases the performance of a MLP by 2.5 times and the rotating LCP by 5 times, when compared to an open pipe particularly for low sun elevation angles.

Evaluation of valuation of noise amelioration treatments within and outside the road reserve

In urban environments road traffic volumes are increasing and the density of living is becoming higher. As a consequence the urban community is being exposed to increasing levels of road traffic noise. It is also evident that the noise reduction potential of within-the-road-reserve treatments such as noise barriers, mounding and pavement surfacing has been exhausted. This paper presents a strategy that involves the comparison of noise ameliorative treatments both within and outside the road reserve. The noise reduction resulting from the within-the-road-reserve component of treatments has been evaluated using a leading application of the CoRTN Model, developed by the UK Department of Transport 1988 [1], and the outside road reserve treatment has been evaluated in accordance with the Australian Standard 3671, Acoustics – Road traffic noise intrusion – Building sitting and construction [5]. The evaluation of noise treatments has been undertaken using a decision support tool (DST) currently being developed under the research program conducted at RMIT University and Department of Main Roads, Queensland. The case study has been based on data from a real project in Queensland, Australia. The research described here was carried out by the Australian Cooperative Research Centre for Construction Innovation [9], in collaboration with Department of Main Roads, Queensland, Department of Public Works, Queensland, Arup Pty. Ltd., Queensland University of technology and RMIT University.

Combination strategies for a factor analysis phone-conditioned speaker verification system

This work aims to take advantage of recent developments in joint factor analysis (JFA) in the context of a phonetically conditioned GMM speaker verification system. Previous work has shown performance advantages through phonetic conditioning, but this has not been shown to date with the JFA framework. Our focus is particularly on strategies for combining the phone-conditioned systems. We show that the classic fusion of the scores is suboptimal when using multiple GMM systems. We investigate several combination strategies in the model space, and demonstrate improvement over score-level combination as well as over a non-phonetic baseline system. This work was conducted during the 2008 CLSP Workshop at Johns Hopkins University.