COSMO—Software for designing smoke control systems in high-rise buildings

A differential computer model specifically designed to quantify smoke movement during a fire in a high-rise structure is described. The basic conservation equations are transformed into a computer code which can be used to determine the paths that smoke will take during a fire. The program is a tool for fire protection engineers to design a smoke management plan with the ultimate goal of improving occupant safety in the event of a fire. The computer code is based on a modified and improved differential smoke control model for the conditions in the floor spaces, stairwells and elevator shafts and it considers a complete set of variables that influence the motion of smoke throughout the building. Program output suggests ways to alter the pressure distribution within the building by using air handling equipment, so that occupants will have smoke-free areas on the floors and inside of the fire escape stairwells. Results for several example cases are provided, and the results are used to illustrate how smoke movement can be managed in order to mitigate dangerous conditions within the building.     

Thirty years of action for energy efficiency in buildings: what are the results?

In the autumn of 1973 a first energy crisis swept over the industrialized world. In 1979 a second followed. The first reactions in the West reflected panic, but soon a correcting policy emerged with rational use of energy as one of the corner stones. From the beginning, buildings got special attention. Their share in the annual national end energy consumption, in fact, was unexpectedly high, while less consumption of highly valued energy sources looked affordable without jeopardizing building usability. On the contrary, better was possible with less. One may expect that three decennia later, the results of such policy should be visible in terms of less energy consumed in buildings. This is not the case, at least not in Flanders, Belgium. Many reasons explain that anomaly. The average principal, designer, builder and contractor is not interested in energy efficiency. Investment costs and not future annual costs are the main concern. Legislation has been introduced reflecting a far too optimistic view on citizenship and thus, without any enforcement policy. The housing and tertiary building stock still expands, with a clear prosperity‐linked trend towards detached dwellings with low compactness and large floor area. Urban planning remains business as usual. And finally, policy makers forgot to consider rebound effects and the impact of lazy workmanship when predicting the efficiency of fabric and building services related measures, resulting in an overestimation of future avoided energy use, while at the same time they underestimated the inertia of such large system as the existing building stock, given the low retrofit and substitution rate.     

Environmental efficiency in residential buildings – A simplified communication approach

For all actors involved with planning, developing and managing buildings, the environmental impact relating to energy use and the quality of the indoor environment are both aspects of major concern. It is crucial that a reduction in the environmental impact of a building is not achieved through compromising the indoor environment. This paper presents a method to assess user satisfaction related to the indoor environment and the environmental impact related to the energy use of the building, i.e. the environmental efficiency of the building. This environmental efficiency comprises two indices that are calculated separately but displayed in the same diagram to facilitate communication of complex information. This approach forms part of the Swedish life cycle based environmental assessment tool for buildings, EcoEffect. The present paper presents and exemplifies the environmental efficiency of buildings using data from 26 Swedish multi-family residential buildings and proposes a number of reference values. The concept can be used as an overarching objective for environmental management of a property firm's building stock or for evaluating targets set in the planning process for a new building. It can also be used for environmental rating of buildings, which would probably increase the communication value further. The aggregated indices are rough but proportionately straightforward to calculate and easily communicated. In addition, they address the environmental impacts of buildings in a much more comprehensive way than the current practice.     

LCA benchmarks for residential buildings in Northern Italy and Denmark – learnings from comparing two different contexts

ABSTRACT

This study provides LCA reference benchmarks for residential buildings in Northern Italy and Denmark. Furthermore, the benchmark derivation process is analysed to highlight the trade-offs that relate to the methodological choices made by benchmark developers, considering the objectives of the stakeholders. Reference benchmarks for the two contexts are calculated based on national samples of residential buildings. A comparative analysis pinpoints the methodological factors regarding system boundaries, inventory requirements and databases that, from a calculation aspect, affect the benchmarks. Results thus highlight the uniqueness of each benchmarking system put into practice, and emphasize the need for clear calculation rules and transparency within each benchmark system. The identified trade-offs from the derivation process furthermore indicate the inherent need to balance the different interests relating to the stakeholders’ roles when applying the benchmark. The mapping of different trade-offs presented in this study provides benchmark stakeholders with an overview that allows for open discussion about which priorities and choices will fit a specific context of benchmark application.     

Thermal comfort in residential buildings – Failure to predict by Standard model

A field study, conducted in 189 dwellings in winter and 205 dwellings in summer, included measurement of hygro-thermal conditions and documentation of occupant responses and behavior patterns. Both samples included both passive and actively space-conditioned dwellings. Predicted mean votes (PMV) computed using Fanger's model yielded significantly lower-than-reported thermal sensation (TS) values, especially for the winter heated and summer air-conditioned groups. The basic model assumption of a proportional relationship between thermal response and thermal load proved to be inadequate, with actual thermal comfort achieved at substantially lower loads than predicted. Survey results also refuted the model's second assumption that symmetrical responses in the negative and positive directions of the scale represent similar comfort levels. Results showed that the model's curve of predicted percentage of dissatisfied (PPD) substantially overestimated the actual percentage of dissatisfied within the partial group of respondents who voted TS > 0 in winter as well as within the partial group of respondents who voted TS < 0 in summer. Analyses of sensitivity to possible survey-related inaccuracy factors (metabolic rate, clothing thermal resistance) did not explain the systematic discrepancies. These discrepancies highlight the role of contextual variables (local climate, expectations, available control) in thermal adaptation in actual settings. Collected data was analyzed statistically to establish baseline data for local standardized thermal and energy calculations. A 90% satisfaction criterion yielded 19.5 °C and 26 °C as limit values for passive winter and summer design conditions, respectively, while during active conditioning periods, set-point temperatures of 21.5 °C and 23 °C should be assumed for winter and summer, respectively.     

Controlling sewer systems – a critical review based on systems in three EU cities

The term Real Time Control (RTC) is widely used to describe all types of control systems in sewer systems. Today the term covers everything from the simplest to the most advanced types of control systems, making it difficult to communicate about sewer system control in a precise manner, as well as search and find specific types of control systems for comparison. Through a survey of implemented control systems in three EU cities today and with the perspectives of current research within the field of sewer system control, the needs for a new control system design framework is identified. With the basis of existing frameworks for control system design, a new time-scale dependent framework is proposed. We believe this comprehensive time-scale dependent framework can help water utilities to retrofit and design new control solutions and facilitate knowledge sharing about existing designs.     

Perforated SIFCON blocks – An extraordinarily ductile material ideal for use in compression yielding structural systems

Compression yielding (CY), an innovative structural concept, has recently been introduced to offset the ductility deficiency of concrete structures reinforced with fiber-reinforced polymer. The CY structural scheme employs a ductile material to replace concrete in the compression side of a plastic hinge, thus allowing the ductile flexural deformation of the member to be achieved through the compressive, rather than tensile, yielding of that member. The CY system makes an extraordinarily high ductility demand on the compression yielding material. Although slurry infiltrated fiber concrete (SIFCON) is a very ductile material, it is still unable to satisfy the excessive ductility demand of this system. However, through the extensive experimental testing reported in this paper, it is found that the high ductility demand of the CY material can be satisfied by providing perforations inside a SIFCON block. This paper reports the experimental testing and its results. From analyses of the test results, a methodology for the design and construction of an adequate CY block is proposed.     

Smart partition system – A room level support system for integrating smart technologies into existing buildings

We proposed a support system called the “Smart Partition System” for infill elements that integrate smart technologies according to the Open Building principles. The design requirements were collected from design practitioners. These design requirements consisted of both architectural and information subsystems. The Smart Partition System was composed of the following multiple levels of smartness: the foundation/core level with an embedded design knowledge in the support system and the utility level with a modular infill that integrate smart technologies. We constructed functional prototypes to demonstrate the feasibility of our proposed support system and some of the possibilities of the smart infill elements. Furthermore, the prototypes were evaluated by design practitioners. We compared our approach with current practices of smart building developments, and we also discussed some future prospects.     

Harnessing buildings’ operational diversity in a computational framework for high-resolution urban energy modeling

To achieve computational efficiency, efforts toward developing urban-scale energy modeling applications frequently rely on various domain simplifications. For instance, heat transfer phenomena are captured using reduced order models. As a consequence, specific aspects pertaining to the temporal dynamics of energy load patterns and their dependency on transient phenomena (e.g., weather conditions, inhabitants’ presence and actions) cannot be realistically represented. To address this circumstance, we have conceived, implemented, and documented a two-step urban energy modeling approach that combines cluster analysis and sampling techniques, full dynamic numeric simulation capability, and stochastic methods. The paper describes the suggested urban energy modeling approach and the embedded cluster analysis supported sampling methodology. More particularly we focus on the aspects of this approach that explicitly involve the representation of inhabitants in urban-scale energy modeling. In this regard, the potential to recover lost dynamic diversity (e.g., in computation of temporal load patterns) due to the deployed reductive sampling is explored. Parametric runs based on stochastic variations of underlying building use profiles facilitate the generation of highly realistic load patterns despite the small number of buildings selected to represent the simulation domain. We illustrate the utility of the proposed urban energy modeling approach to address queries concerning the energy efficiency potential of behaviorally effective instruments. The feasibility of the envisioned scenarios concerning inhabitants and their behavior (high-resolution temporal load prediction, assessment of behavioral variation) is presented in detail via specific instances of district-level energy modeling for the city of Vienna, Austria.     

Informal settlement upgrading in South Africa: beneficiaries’ perceptions over nearly twenty-five years

Research on informal settlement upgrading tends to focus on one-off case studies. This article investigates the changing experiences, over nearly 25 years, of people living in an upgraded informal settlement. We sought to determine how the perceptions of the residents of Freedom Square changed. Our latest survey (2014) included responses from 199 household representatives and followed earlier surveys. Firstly, we find that the upgrading of Freedom Square represents a first step towards ensuring the housing rights of black people in urban South Africa. Secondly, spatial infilling and locational advantage continue to play valuable roles. Thirdly, dweller control, in terms of which residents themselves are able to design extensions to their houses, remains important. Fourthly, social cohesion among community members is proving to be more important than access to a stand. Fifthly, urban management remains an important long-term requirement. Lastly, elements of informality persist in the area.     

Direct chiller power limiting for peak demand limiting control in buildings—Methodology and on-site validation

Large electricity consumers are often charged of a high price for their peak demand for the purpose of reducing the capacity and cost, as well as the operation reliability of electricity transmission facilities. As a result, even one spike in the monthly demand profile would result in a significant increase in electricity bill. Peak demand limiting techniques provide an effective and efficient means to reduce such cost. For instance, the methods to utilize cooling/heating stored in building thermal mass by resetting space air temperature set-point have been proofed effective in many studies. This study proposes a direct chiller power limiting control strategy for peak demand limiting control in buildings, particularly during the period of chiller starting when the peak demand occurs mostly. Validation tests were conducted on-site in a super high rise building and on a dynamic simulation platform. Results showed the strategy was effective in reducing the peak demand during chiller starting periods.     

Study on seismic base shear factor in Chinese ＇Code for seismic design of buildings＇

介绍了基底地震剪力的影响因素及美国、新西兰、加拿大及欧洲抗震规范采用振型分解反应谱法进行分析时的基底地震剪力最小需求,并从中美规范剪力系数所考虑因素的对比及高阶振型对长周期结构基底地震剪力影响的分析中发现,剪力系数应满足2个必要条件：剪力系数应与反应谱形状（由场地类型等因素决定）相关;剪力系数应反映高阶振型的影响,即满足单调性条件。根据SEAOC的研究报告,针对我国GB 50011—2010《建筑抗震设计规范》剪力系数计算式存在的不足,提出了修正建议。对比分析表明,修正后的剪力系数计算式更符合基底地震剪力的特性,且工程适用范围更广,可为抗震规范今后的修订提供参考。     

La Perla – 100 years of informal architecture in San Juan,Puerto Rico

La Perla, Puerto Rico's most famous informal settlement, developed since the early 1900s outside the fortifications of San Juan's colonial Old Town, the country's main tourist attraction. In the mid-twentieth century, La Perla was a symbol of the poverty and deprivation that development and scientifically informed planning attempted to remove. Since the 1970s, La Perla has been a subject of various improvement plans by the local authority with varying degrees of inhabitant participation. Thus, La Perla is connected with the great hopes and fears of the twentieth century: the promise of modernization and progress and the ensuing disappointments, the limitations of top-down decision-making and expert planning, the distress of poverty and marginalization, the opportunities of self-organization and informality, and the threat of forced relocation imposed by gentrification cycles. Based on previously unpublished archival materials, this article presents an architectural and planning history of La Perla. It compares building types, ownership structures, and municipal policies throughout the 100 years of La Perla's existence. The article challenges the distinction that legitimizes formal housing as the rule and informal abodes as an environment that is fundamentally different from the formal city. In La Perla, formal and informal did not constitute polar opposites, but have to be regarded as two aspects of the same urbanization process. In this sense, La Perla is an intrinsic part of San Juan's architectural heritage.     

Cost–benefit analysis for optimal distributed generation placement in distribution systems

This paper presents an optimisation method to determine optimal allocations of distributed generation (DGs) and capacitors based on maximisation of a profit/worth analysis approach. The optimal locations and sizes of DGs and capacitors have been determined by minimising the power distribution loss. This method considers various technical and economic factors such as line losses, sizes of DGs and capacitors at optimal locations, investment costs, operating costs and maintenance costs of DG and capacitor to achieve the objective for a predetermined number. The electricity market price of grid power has been considered to recover initial investment in a specified time period. The improvement in the voltage profile of the system has also been considered in this work. The particle swarm optimisation technique has been used to solve the optimal placement of DGs and capacitors to maximise the profit. The proposed technique is tested on 33-bus and 69-bus test systems.     

‘But that is a systems solution to me’ – negotiations in IT design

In this paper we argue that it is not self-evident how ‘requirements’ are defined, but that ‘requirements’ are enacted differently by differently situated actors, and that this has consequences in design practices. The purpose of the paper is to explore the consequences of prototyping practices in a local IT design project. The empirical material was gathered through the use of ethnographic methods, and analysed diffractively. Graphical user interface prototypes were tools for formulating business requirements in a business process analysis. Through a reading of a discussion which took place in a work meeting about the prototypes, we discuss how business requirements were enacted. This is discussed in relation to divergent and convergent approaches in IT design. One consequence was a risk that the prototyping process moved too fast to solutions, and another was the risk that the business process analysis method reproduced the dominant story of women's absence in IT design.     

Impacts of climate change on urban drainage systems – a case study in Fredrikstad,Norway

Norway has frequently encountered flood damage in urban areas during recent years. In this paper the authors, taking Veumdalen catchment in Fredrikstad as an example, simulated the possible consequences in the sewer system, in the present, predicted and artificial climate scenarios. Indicators that describe (1) surface flooding, (2) surcharging sewers, (3) basement flooding and (4) combined sewer overflow (CSO) are defined to represent the adverse effects of climate change. It is concluded from the annual-based simulation that the total volume of water spilling from the flooding manholes will increase 2–4-times the increase in precipitation, and the total CSO will increase 1.5–3-times as much as the increase in precipitation. The simulation results also show that the number of flooding manholes and number of surcharging sewers may change dramatically and irregularly with a slight change of precipitation, and vary with events and durations.     

Landscape dynamics of Mediterranean montane grasslands over 60 years and implications for habitats conservation. A case study in the northern Apennines (Italy)

Widespread trends of abandonment have strongly affected Mediterranean mountains after the Second World War, triggering spontaneous recolonisation of forests. A diachronic analysis of the landscape in a Natura 2000 site (Tuscany, Italy) was carried out using digital aerial photographs (1954, 2013) and a GIS-based methodology, focusing on territories above 1300 m a.s.l. The detected variations of total areas, patch shape, patch dimensions and selected metrics showed a notable shift of the vegetation towards woody types and a drastic reduction of open grasslands, some with high conservation value, accompanied by a strong increase in patch number, surface and edge. A decrease of SDI and SEI diversity indices was also observed. Considering that fragmentation is one of the main causes threatening habitats and species, our results point out a clear necessity for a monitoring programme and suitable actions aimed at improving the status of biodiversity-rich montane grasslands.     

Validation of numerical predictions for liquefaction phenomenon – Lateral spreading in clean sands

During the last few decades, important efforts and developments in the computational modeling of geo-materials have contributed to an increase in the accuracy of the predictions of the dynamic responses of soil systems. Due to their catastrophic consequences, special emphasis has been placed on liquefaction-induced ground failures. However, the numerical tools for liquefaction modeling need to be continually assessed and validated in order to enhance their reliability and enable them to be included in design practices.Within that context, the main objective of this paper was to present a complete validation exercise that explores the capabilities of the numerical predictions to simulate the lateral spreading phenomenon in clean sands under a diverse range of densities and input motions. The validation exercise used the “Strain Space Multiple Mechanism Model” to simulate the lateral spreading phenomenon (although the methodology presented here might be applicable for the validation of other numerical tools as well), and was based on multiple, cross-checked, and high-quality physical models (centrifuge models) and element tests (hollow cylinder cyclic shear tests).Special focus was placed on the quantification of the median response and the associated variability of both physical and numerical models, including an analysis of the importance of the proper selection of validation metrics.The comparison showed that the numerical model is able to predict the displacements for the median trend and the 95% probability confidence bounds for PGA < 0.25 g.     

Optimized maintenance and renovation scheduling in multifamily buildings – a systematic approach based on condition state and life cycle cost of building components

Proactive maintenance strategies in principle are devised to control degradation and sustain optimal performance of building components. While realizing the technical necessities, they also serve as an instrument towards multiple and often conflicting objectives during financial constraints. An optimal proactive maintenance strategy therefore should comprise a multiannual maintenance action plan optimized on different criteria corresponding to owners’ objectives under existing constraints. This study offers a systematic approach based on a condition-deterioration model to address the complexity involved in decision making regarding optimized maintenance and renovation planning. Life-cycle cost analysis in form of Equivalent Annual Cost (EAC) is used for the economic assessment of maintenance/renovation scenarios. In this paper, the model is used to compare the economy of different maintenance/renovation plans in a chosen scenario in order to determine the optimal maintenance interval for a single and a combination of building components. Two façade elements, windows and façade rendering, are used to illustrate the application of the proposed method. This method is intended to help decision makers at both design and post-construction phases in the choice of both building components and maintenance/renovation strategies.