An integrated dynamic whole life costing analysis for air distribution systems

Air distribution systems are one of the major electrical energy consumers in air-conditioned commercial buildings which maintain comfortable indoor thermal environment and air quality by supplying specified amounts of treated air into different zones. The sizes of air distribution lines affect energy efficiency of the distribution systems. Equal friction and static regain are two well-known approaches for sizing the air distribution lines. Concerns to life cycle cost of the air distribution systems, T and IPS methods have been developed. Hitherto, all these methods are based on static design conditions. Therefore, dynamic performance of the system has not been yet addressed; whereas, the air distribution systems are mostly performed in dynamic rather than static conditions. Besides, none of the existing methods consider any aspects of thermal comfort and environmental impacts. This study attempts to investigate the existing methods for sizing of the air distribution systems and proposes a dynamic approach for size optimisation of the air distribution lines by taking into account optimisation criteria such as economic aspects, environmental impacts and technical performance. These criteria have been respectively addressed through whole life costing analysis, life cycle assessment and deviation from set-point temperature of different zones. Integration of these criteria into the TRNSYS software produces a novel dynamic optimisation approach for duct sizing. Due to the integration of different criteria into a well- known performance evaluation software, this approach could be easily adopted by designers in busy nature of design. Comparison of this integrated approach with the existing methods reveals that under the defined criteria, system performance is improved up to 15% compared to the existing methods. This approach is interpreted as a significant step forward reaching to the net zero emission building in future.

Decision making for HVAC&R system selection for a typical office building in the UK

Demands for thermal comfort, better indoor air quality together with lower environmental impacts have had ascending trends in the last decade. In many circumstances, these demands could not be fully covered through the soft approach of bioclimatic design like optimisation of the building orientation and internal layout. This is mostly because of the dense urban environment and building internal energy loads. In such cases, heating, ventilation, air-conditioning and refrigeration (HVAC&R) systems make a key role to fulfill the requirements of indoor environment. Therefore, it is required to select the most proper HVAC&R system. In this study, a robust decision making approach for HVAC&R system selection is proposed. Technical performance, economic aspect and environmental impacts of 36 permutations of primary and secondary systems are taken into account to choose the most proper HVAC&R system for a case study office building. The building is a representative for the dominant form of office buildings in the UK. Dynamic performance evaluation of HVAC&R alternatives using TRNSYS package together with life cycle energy cost analysis provides a reliable basis for decision making. Six scenarios broadly cover the decision makers' attitudes on HVAC&R system selection which are analysed through Analytical Hierarchy Process (AHP). One of the significant outcomes reveals that, despite both the higher energy demand and more investment requirements associated with compound heating, cooling and power system (CCHP); this system is one of the top ranked alternatives due to the lower energy cost and C02 emissions. The sensitivity analysis reveals that in all six scenarios, the first five top ranked alternatives are not changed. Finally, the proposed approach and the results could be used by researchers and designers especially in the early stages of a design process in which all involved bodies face the lack of time, information and tools for evaluation of a variety of systems.

Building a tropical-extratropical cloud band metbot

An automated cloud band identification procedure is developed that captures the meteorology of such events over southern Africa. This “metbot” is built upon a connected component labelling method that enables blob detection in various atmospheric fields. Outgoing longwave radiation is used to flag candidate cloud band days by thresholding the data and requiring detected blobs to have sufficient latitudinal extent and exhibit positive tilt. The Laplacian operator is used on gridded reanalysis variables to highlight other features of meteorological interest. The ability of this methodology to capture the significant meteorology and rainfall of these synoptic systems is tested in a case study. Usefulness of the metbot in understanding event to event similarities of meteorological features is demonstrated, highlighting features previous studies have noted as key ingredients to cloud band development in the region. Moreover, this allows the presentation of a composite cloud band life cycle for southern Africa events. The potential of metbot to study multiscale interactions is discussed, emphasising its key strength: the ability to retain details of extreme and infrequent events. It automatically builds a database that is ideal for research questions focused on the influence of intraseasonal to interannual variability processes on synoptic events. Application of the method to convergence zone studies and atmospheric river descriptions is suggested. In conclusion, a relation-building metbot can retain details that are often lost with object-based methods but are crucial in case studies. Capturing and summarising these details may be necessary to develop deeper process-level understanding of multiscale interactions.

Evaluation of malacosporean life cycles through transmission studies

Myxozoans, belonging to the recently described Class Malacosporea, parasitise freshwater bryozoans during at least part of their life cycle, but no complete malacosporean life cycle is known to date. One of the 2 described malacosporeans is Tetracapsuloides bryosalmonae, the causative agent of salmonid proliferative kidney disease. The other is Buddenbrockia plumatellae, so far only found in freshwater bryozoans. Our investigations evaluated malacosporean life cycles, focusing on transmission from fish to bryozoan and from bryozoan to bryozoan. We exposed bryozoans to possible infection from: stages of T bryosalmonae in fish kidney and released in fish urine; spores of T bryosalmonae that had developed in bryozoan hosts; and spores and sac stages of B. plumatellae that had developed in bryozoans. Infections were never observed by microscopic examination of post-exposure, cultured bryozoans and none were detected by PCR after culture. Our consistent negative results are compelling: trials incorporated a broad range of parasite stages and potential hosts, and failure of transmission across trials cannot be ascribed to low spore concentrations or immature infective stages. The absence of evidence for bryozoan to bryozoan transmissions for both malacosporeans strongly indicates that such transmission is precluded in malacosporean life cycles. Overall, our results imply that there may be another malacosporean host which remains unidentified, although transmission from fish to bryozoans requires further investigation. However, the highly clonal life history of freshwater bryozoans is likely to allow both long-term persistence and spread of infection within bryozoan populations, precluding the requirement for regular transmission from an alternate host.

The need of sustainable buildings construction in the Kingdom of Bahrain

This thesis is aimed to initiate implementing sustainable building construction in the kingdom of Bahrain, i.e. Building-Integration PhotoVoltaic (BIPV) or Wind Energy (BIWE). It highlights the main constrains that discourage such modern concept in building and construction. Three groups have been questioned using a questionnaire. These are the policy and decision makers, the leading consultants and the contractors. The main constrains of the dissemination of BIVP and BIWE, according to the policy and decision makers, are: lack of knowledge and awareness of the public in sustainable technology, low cost of electricity, low cost of gas and oil and difficulty in applying local environmental taxes. The consultants had attributed the constrains to ignorance of life cycle cost of PV and Wind turbines systems, lack of education and knowledge in sustainable design, political system, shortage of markets importing sustainable technologies and client worries in profitability and pay-back period. The contractors are found to be very enthusiastic and ready to take over any sustainable building project and prefer to have a construction manger to coordinate between the design and contracting team. Design and Build is found the favorable procurement method in Bahrain for conducting BIPV or BIWE projects.

The diurnal cycle in the tropics

A global archive of high-resolution (3-hourly, 0.58 latitude–longitude grid) window (11–12 mm) brightness temperature (Tb) data from multiple satellites is being developed by the European Union Cloud Archive User Service (CLAUS) project. It has been used to construct a climatology of the diurnal cycle in convection, cloudiness, and surface temperature for all regions of the Tropics. An example of the application of the climatology to the evaluation of the climate version of the U.K. Met. Office Unified Model (UM), version HadAM3, is presented. The characteristics of the diurnal cycle described by the CLAUS data agree with previous observational studies, demonstrating the universality of the characteristics of the diurnal cycle for land versus ocean, clear sky versus convective regimes. It is shown that oceanic deep convection tends to reach its maximum in the early morning. Continental convection generally peaks in the evening, although there are interesting regional variations, indicative of the effects of complex land–sea and mountain–valley breezes, as well as the life cycle of mesoscale convective systems. A striking result from the analysis of the CLAUS data has been the extent to which the strong diurnal signal over land is spread out over the adjacent oceans, probably through gravity waves of varying depths. These coherent signals can be seen for several hundred kilometers and in some instances, such as over the Bay of Bengal, can lead to substantial diurnal variations in convection and precipitation. The example of the use of the CLAUS data in the evaluation of the Met. Office UM has demonstrated that the model has considerable difficulty in capturing the observed phase of the diurnal cycle in convection, which suggests some fundamental difficulties in the model’s physical parameterizations. Analysis of the diurnal cycle represents a powerful tool for identifying and correcting model deficiencies.

Forest soil carbon cycle under elevated CO2 – a case of increased throughput?

Forest soils account for a large part of the stable carbon pool held in terrestrial ecosystems. Future levels of atmospheric CO2 are likely to increase C input into the soils through increased above- and below-ground production of forests. This increased input will result in greater sequestration of C only if the additional C enters stable pools. In this review, we compare current observations from four large-scale Free Air FACE Enrichment (FACE) experiments on forest ecosystems (EuroFACE, Aspen-FACE, Duke FACE and ORNL-FACE) and consider their predictive power for long-term C sequestration. At all sites, FACE increased fine root biomass, and in most cases higher fine root turnover resulted in higher C input into soil via root necromass. However, at all sites, soil CO2 efflux also increased in excess of the increased root necromass inputs. A mass balance calculation suggests that a large part of the stimulation of soil CO2 efflux may be due to increased root respiration. Given the duration of these experiments compared with the life cycle of a forest and the complexity of processes involved, it is not yet possible to predict whether elevated CO2 will result in increased C storage in forest soil.

Data uncertainty in real estate forecasting

The rapid expansion of the TMT sector in the late 1990s and more recent growing regulatory and corporate focus on business continuity and security have raised the profile of data centres. Data centres offer a unique blend of occupational, physical and technological characteristics compared to conventional real estate assets. Limited trading and heterogeneity of data centres also causes higher levels of appraisal uncertainty. In practice, the application of conventional discounted cash flow approaches requires information about a wide range of inputs that is difficult to derive from limited market signals or estimate analytically. This paper outlines an approach that uses pricing signals from similar traded cash flows is proposed. Based upon ‘the law of one price’, the method draws upon the premise that two identical future cash flows must have the same value now. Given the difficulties of estimating exit values, an alternative is that the expected cash flows of data centre are analysed over the life cycle of the building, with corporate bond yields used to provide a proxy for the appropriate discount rates for lease income. Since liabilities are quite diverse, a number of proxies are suggested as discount and capitalisation rates including indexed-linked, fixed interest and zero-coupon bonds. Although there are rarely assets that have identical cash flows and some approximation is necessary, the level of appraiser subjectivity is dramatically reduced.

The appraisal of data centres: deconstructing the cash flow

This paper analyses the appraisal of a specialized form of real estate - data centres - that has a unique blend of locational, physical and technological characteristics that differentiate it from conventional real estate assets. Market immaturity, limited trading and a lack of pricing signals enhance levels of appraisal uncertainty and disagreement relative to conventional real estate assets. Given the problems of applying standard discounted cash flow, an approach to appraisal is proposed that uses pricing signals from traded cash flows that are similar to the cash flows generated from data centres. Based upon ‘the law of one price’, it is assumed that two assets that are expected to generate identical cash flows in the future must have the same value now. It is suggested that the expected cash flow of assets should be analysed over the life cycle of the building. Corporate bond yields are used to provide a proxy for the appropriate discount rates for lease income. Since liabilities are quite diverse, a number of proxies are suggested as discount and capitalisation rates including indexed-linked, fixed interest and zero-coupon bonds.

Design and management of sustainable built environments

The United Nation Intergovernmental Panel on Climate Change (IPCC) makes it clear that climate change is due to human activities and it recognises buildings as a distinct sector among the seven analysed in its 2007 Fourth Assessment Report. Global concerns have escalated regarding carbon emissions and sustainability in the built environment. The built environment is a human-made setting to accommodate human activities, including building and transport, which covers an interdisciplinary field addressing design, construction, operation and management. Specifically, Sustainable Buildings are expected to achieve high performance throughout the life-cycle of siting, design, construction, operation, maintenance and demolition, in the following areas: • energy and resource efficiency; • cost effectiveness; • minimisation of emissions that negatively impact global warming, indoor air quality and acid rain; • minimisation of waste discharges; and • maximisation of fulfilling the requirements of occupants’ health and wellbeing. Professionals in the built environment sector, for example, urban planners, architects, building scientists, engineers, facilities managers, performance assessors and policy makers, will play a significant role in delivering a sustainable built environment. Delivering a sustainable built environment needs an integrated approach and so it is essential for built environment professionals to have interdisciplinary knowledge in building design and management . Building and urban designers need to have a good understanding of the planning, design and management of the buildings in terms of low carbon and energy efficiency. There are a limited number of traditional engineers who know how to design environmental systems (services engineer) in great detail. Yet there is a very large market for technologists with multi-disciplinary skills who are able to identify the need for, envision and manage the deployment of a wide range of sustainable technologies, both passive (architectural) and active (engineering system),, and select the appropriate approach. Employers seek applicants with skills in analysis, decision-making/assessment, computer simulation and project implementation. An integrated approach is expected in practice, which encourages built environment professionals to think ‘out of the box’ and learn to analyse real problems using the most relevant approach, irrespective of discipline. The Design and Management of Sustainable Built Environment book aims to produce readers able to apply fundamental scientific research to solve real-world problems in the general area of sustainability in the built environment. The book contains twenty chapters covering climate change and sustainability, urban design and assessment (planning, travel systems, urban environment), urban management (drainage and waste), buildings (indoor environment, architectural design and renewable energy), simulation techniques (energy and airflow), management (end-user behaviour, facilities and information), assessment (materials and tools), procurement, and cases studies ( BRE Science Park). Chapters one and two present general global issues of climate change and sustainability in the built environment. Chapter one illustrates that applying the concepts of sustainability to the urban environment (buildings, infrastructure, transport) raises some key issues for tackling climate change, resource depletion and energy supply. Buildings, and the way we operate them, play a vital role in tackling global greenhouse gas emissions. Holistic thinking and an integrated approach in delivering a sustainable built environment is highlighted. Chapter two demonstrates the important role that buildings (their services and appliances) and building energy policies play in this area. Substantial investment is required to implement such policies, much of which will earn a good return. Chapters three and four discuss urban planning and transport. Chapter three stresses the importance of using modelling techniques at the early stage for strategic master-planning of a new development and a retrofit programme. A general framework for sustainable urban-scale master planning is introduced. This chapter also addressed the needs for the development of a more holistic and pragmatic view of how the built environment performs, , in order to produce tools to help design for a higher level of sustainability and, in particular, how people plan, design and use it. Chapter four discusses microcirculation, which is an emerging and challenging area which relates to changing travel behaviour in the quest for urban sustainability. The chapter outlines the main drivers for travel behaviour and choices, the workings of the transport system and its interaction with urban land use. It also covers the new approach to managing urban traffic to maximise economic, social and environmental benefits. Chapters five and six present topics related to urban microclimates including thermal and acoustic issues. Chapter five discusses urban microclimates and urban heat island, as well as the interrelationship of urban design (urban forms and textures) with energy consumption and urban thermal comfort. It introduces models that can be used to analyse microclimates for a careful and considered approach for planning sustainable cities. Chapter six discusses urban acoustics, focusing on urban noise evaluation and mitigation. Various prediction and simulation methods for sound propagation in micro-scale urban areas, as well as techniques for large scale urban noise-mapping, are presented. Chapters seven and eight discuss urban drainage and waste management. The growing demand for housing and commercial developments in the 21st century, as well as the environmental pressure caused by climate change, has increased the focus on sustainable urban drainage systems (SUDS). Chapter seven discusses the SUDS concept which is an integrated approach to surface water management. It takes into consideration quality, quantity and amenity aspects to provide a more pleasant habitat for people as well as increasing the biodiversity value of the local environment. Chapter eight discusses the main issues in urban waste management. It points out that population increases, land use pressures, technical and socio-economic influences have become inextricably interwoven and how ensuring a safe means of dealing with humanity’s waste becomes more challenging. Sustainable building design needs to consider healthy indoor environments, minimising energy for heating, cooling and lighting, and maximising the utilisation of renewable energy. Chapter nine considers how people respond to the physical environment and how that is used in the design of indoor environments. It considers environmental components such as thermal, acoustic, visual, air quality and vibration and their interaction and integration. Chapter ten introduces the concept of passive building design and its relevant strategies, including passive solar heating, shading, natural ventilation, daylighting and thermal mass, in order to minimise heating and cooling load as well as energy consumption for artificial lighting. Chapter eleven discusses the growing importance of integrating Renewable Energy Technologies (RETs) into buildings, the range of technologies currently available and what to consider during technology selection processes in order to minimise carbon emissions from burning fossil fuels. The chapter draws to a close by highlighting the issues concerning system design and the need for careful integration and management of RETs once installed; and for home owners and operators to understand the characteristics of the technology in their building. Computer simulation tools play a significant role in sustainable building design because, as the modern built environment design (building and systems) becomes more complex, it requires tools to assist in the design process. Chapter twelve gives an overview of the primary benefits and users of simulation programs, the role of simulation in the construction process and examines the validity and interpretation of simulation results. Chapter thirteen particularly focuses on the Computational Fluid Dynamics (CFD) simulation method used for optimisation and performance assessment of technologies and solutions for sustainable building design and its application through a series of cases studies. People and building performance are intimately linked. A better understanding of occupants’ interaction with the indoor environment is essential to building energy and facilities management. Chapter fourteen focuses on the issue of occupant behaviour; principally, its impact, and the influence of building performance on them. Chapter fifteen explores the discipline of facilities management and the contribution that this emerging profession makes to securing sustainable building performance. The chapter highlights a much greater diversity of opportunities in sustainable building design that extends well into the operational life. Chapter sixteen reviews the concepts of modelling information flows and the use of Building Information Modelling (BIM), describing these techniques and how these aspects of information management can help drive sustainability. An explanation is offered concerning why information management is the key to ‘life-cycle’ thinking in sustainable building and construction. Measurement of building performance and sustainability is a key issue in delivering a sustainable built environment. Chapter seventeen identifies the means by which construction materials can be evaluated with respect to their sustainability. It identifies the key issues that impact the sustainability of construction materials and the methodologies commonly used to assess them. Chapter eighteen focuses on the topics of green building assessment, green building materials, sustainable construction and operation. Commonly-used assessment tools such as BRE Environmental Assessment Method (BREEAM), Leadership in Energy and Environmental Design ( LEED) and others are introduced. Chapter nineteen discusses sustainable procurement which is one of the areas to have naturally emerged from the overall sustainable development agenda. It aims to ensure that current use of resources does not compromise the ability of future generations to meet their own needs. Chapter twenty is a best-practice exemplar - the BRE Innovation Park which features a number of demonstration buildings that have been built to the UK Government’s Code for Sustainable Homes. It showcases the very latest innovative methods of construction, and cutting edge technology for sustainable buildings. In summary, Design and Management of Sustainable Built Environment book is the result of co-operation and dedication of individual chapter authors. We hope readers benefit from gaining a broad interdisciplinary knowledge of design and management in the built environment in the context of sustainability. We believe that the knowledge and insights of our academics and professional colleagues from different institutions and disciplines illuminate a way of delivering sustainable built environment through holistic integrated design and management approaches. Last, but not least, I would like to take this opportunity to thank all the chapter authors for their contribution. I would like to thank David Lim for his assistance in the editorial work and proofreading.

Wall materials and techniques available for low cost housing in Khartoum from a sustainability point of view

Khartoum like many cities in least developing countries (LDCs) still witnesses huge influx of people. Accommodation of the new comers leads to encroachment on the cultivation land leads to sprawl expansion of Greater Khartoum. The city expanded in diameter from 16.8 km in 1955 to 802.5 km in 1998. Most of this horizontal expansion was residential. In 2008 Khartoum accommodated 29% of the urban population of Sudan. Today Khartoum is considered as one of 43 major cities in Africa that accommodates more than 1 million inhabitants. Most of new comers live in the outskirts of the city e.g. Dar El-Salam and Mayo neighbourhoods. The majority of those new comers built their houses especially the walls from mud, wood, straw and sacks. Selection of building materials usually depends on its price regardless of the environmental impact, quality, thermal performance and life of the material. Most of the time, this results in increasing the cost with variables of impacts over the environment during the life of the building. Therefore, consideration of the environmental impacts, social impacts and economic impacts is crucial in the selection of any building material. Decreasing such impacts could lead to more sustainable housing. Comparing the sustainability of the available wall building materials for low cost housing in Khartoum is carried out through the life cycle assessment (LCA) technique. The purpose of this paper is to compare the most available local building materials for walls for the urban poor of Khartoum from a sustainability point of view by going through the manufacturing of the materials, the use of these materials and then the disposal of the materials after their life comes to an end. Findings reveal that traditional red bricks couldn’t be considered as a sustainable wall building material that will draw the future of the low cost housing in Greater Khartoum. On the other hand, results of the comparison lead to draw attention to the wide range of the soil techniques and to its potentials to be a promising sustainable wall material for urban low cost housing in Khartoum.

Customer retention management in the recession

The purpose of this article is to explore customer retention strategies and tactics implemented by firms in recession. Our investigations show just how big a challenge many organizations face in their ability to manage customer retention effectively. While leading organizations have embedded real-time customer life cycle management, developed accurate early warning systems, price elasticity models and ‘deal calculators’, the organizations we spoke to have only gone as far as calculating the value at risk and building simple predictive models.