Interventions for large-scale carbon emission reductions in future UK offices

Previous work by the authors has shown the effect that changing climate and small power/lighting equipment can have on heating and cooling loads of typical existing UK offices, for a 2005 baseline. This follow-on study uses an improved office, with reduced cooling loads, and performs retrofit fabric and HVAC measures to further reduce the energy and CO₂ emissions associated. The effect of heat recovery on the proposed “2030 office” is then quantified, showing that such an office can tend towards being “passively heated”. With adaptive comfort also applied, the office CO₂ emissions are estimated for various UK locations. The measures suggest CO₂ emissions relating to heating, cooling and ventilation (HVAC) can be reduced by 61% for the specific office-type studied. The proposed measures are carried out while allowing for a change in activity between 2005 and 2030. When all factors leading to changes in energy use are accounted for, namely small power, lighting, HVAC and climate change, total CO₂ savings of 65% are estimated when compared to the 2005 baseline. In achieving these theoretical savings, the relationship between internal activity and HVAC is studied, and identified as being a crucial area if challenging CO₂ emission targets are to be reached.     

The performance of air-source heat pumps in current and future offices

A typical UK office is used as an exemplar for office energy use in the UK. The effect of replacing existing boilers and air-conditioning systems with air-source heat pumps (ASHPs) is investigated for a “current” version of the office, with typical equipment/lighting usage, fabric and internal gains, and also for a “2030” office, where fabric is improved, equipment/lighting made more efficient and, as a result, internal gains reduced. The ASHPs, as a potential carbon-saving technology, performs slightly differently for the two office scenarios. Furthermore, after removing the boiler, it is found to be important whether electric hot water or gas hot water point-of-use heaters are adopted with the ASHPs (assuming that the existing boiler would not be used if the ASHPs is satisfying all space heating requirements). This can be the difference between ASHPs reducing and increasing the carbon emissions of the office. Finally, the carbon intensity of the grid has a large effect on the success of ASHPs technology. This is quantified through a sensitivity analysis, indicating the external conditions for which ASHPs might reduce CO₂ emissions for office buildings. The results suggest that an ASHPs has the potential to reduce CO₂ emissions for certain conditions, but should not be seen as a guaranteed low-carbon technology for all scenarios. As well as assessing the ASHPs as a carbon-saving technology, potential economic benefits are also estimated based on running costs and predicted reduction in energy bills.     

Assessment of Portuguese thermal building legislation in an energetic and environmental perspective

The aim of this study is to assess the consistency of Portuguese thermal building legislation in terms of energy and environmental performance.To illustrate this, a case study has been carried out for different scenarios of a dwelling home located in an extreme climate zone (I3, V1 north) in Portugal with a T3 typology: four occupants and net floor area of 150 m², modelled according to Regulation Thermal Performance Characteristics of Buildings and a Life Cycle Assessment approach.The results show that the Portuguese thermal building legislation can be considered consistent in terms of energy efficiency and environmental performance if we take the damage categories into account - “human health” or “ecosystem quality” or the impact category - “emission into air”. It cannot be considered consistent if we take the damage category into account - “resources” or the impact category - “CO₂ eq” (equivalent carbon dioxide emissions)/“climate change”/“global warming”.     

Application of energy rating methods to the existing building stock: Analysis of some residential buildings in Turin

The objective of this work is to contribute to the recent standardisation activity, finalized to apply the Energy Performance of Buildings Directive (EPBD). Through the energy assessment of some residential buildings in Turin (Italy), the work investigates the application of the calculation methods that have been specified in the recent European standard for the so-called “standard energy rating”. A comparison of the “calculated energy rating” with the “measured energy rating” is used to investigate the effect of user behaviour and weather conditions. Moreover, in order to draft the energy certificate and make an appropriate classification, the last part of the work investigates the way to find energy reference values of the building stock, through the study of the correlation between the input and the output data of an energy rating and the comparison of the analysed buildings.     

The strategic siting and the roofing area requirements of building-integrated photovoltaic solar energy generators in urban areas in Brazil

Building-integrated photovoltaic (BIPV) generators are typically small and distributed solar power plants that occupy virtually no space because they are part of the building envelope, and they generate power at point of use. A more widespread use of grid-connected photovoltaics (PV) is hindered by a number of reasons which include the declining, but still high costs of the photogenerated kilowatt hour, and the lack of knowledge about the benefits of distributed generation with PV in the urban environment. When strategically sited, PV generators integrated to building façades and rooftops in urban areas at limited penetration levels can benefit local feeders with these distributed “negative loads”. A number of studies have been published, with learning curves demonstrating the cost-reduction potential of large-scale PV production, and in some markets the cost of PV electricity is approaching residential tariffs, the so-called grid parity. Due to the intermittent nature of the solar radiation resource, PV is considered non-despatchable power, but under some conditions, in sunny urban areas with electricity load curves dominated by air-conditioning loads, there is a high correlation between PV generation and feeder loads. In these situations, a considerable fraction of a given PV generator can be considered despatchable power. In this work we assess the potential of building-integrated, grid-connected PV generation in the state capital Florianópolis, in South Brazil. The deployment of six different commercially available PV technologies is compared with total roof area availability, solar generation profiles, and local feeder load curves for a selected number of urban areas in the city. Our results demonstrate the advantages of strategically siting PV generators in the urban environment.     

Turbulence generated by a wind tunnel of multi-fan type in uniformly active and quasi-grid modes

In an attempt to simulate atmospheric turbulence at high-Reynolds numbers, an innovative wind tunnel of “multi-fan type” is developed. The airflow is driven by an array of fans (9 columns × 11 rows), each of which is independently controlled by a computer. A driving mode (“uniformly active mode”) is applied, which has been typically used for turbulence modeling using a smaller wind tunnel. Another mode with grid-like distributed fans that are driven steadily (“quasi-grid mode”) is introduced and found to produce turbulence characteristics similar to the conventional grid turbulence. Comparison of turbulence characteristics of the two modes reveals the turbulence structure of the uniformly active mode.     

Reconstruction of the thermal environment evolution in urban areas from underground temperature distribution

It is possible to estimate the ground surface temperature (GST) history of the past several hundred years from temperature profiles measured in boreholes because the temporal variation in GST propagates into the subsurface by thermal diffusion. This “geothermal method” of reconstructing GST histories can be applied to studies of thermal environment evolution in urban areas, including the development of “heat islands.” Temperatures in boreholes were logged at 102 sites in Bangkok, Jakarta, Taipei, Seoul and their surrounding areas in 2004 to 2007. The effects of recent surface warming can be recognized in the shapes of most of the obtained temperature profiles. The preliminary results of reconstruction of GST histories through inversion analysis show that GST increased significantly in the last century. Existing temperature profile data for the areas in and around Tokyo and Osaka can also be used to reconstruct GST histories. Because most of these cities are located on alluvial plains in relatively humid areas, it is necessary to use a model with groundwater flow and a layered subsurface structure for reconstruction analysis. Long-term records of subsurface temperatures at multiple depths may demonstrate how the GST variation propagates downward through formations. Time series data provide information on the mechanism of heat transfer (conduction or advection) and the thermal diffusivity. Long-term temperature monitoring has been carried out in a borehole located on the coast of Lake Biwa, Japan. Temperatures at 30 and 40 m below the ground surface were measured for 4 years and 2 years, respectively, with a resolution of 1 mK. The obtained records indicate steady increases at both depths with different rates, which is probably the result of some recent thermal event(s) near the surface. Borehole temperatures have also been monitored at selected sites in Bangkok, Jakarta, and Taiwan.     

Rethinking dichotomization: A critical perspective on the use of “hard” and “soft” in project management research

This paper elaborates on the categorization – dichotomization – between “hard” and “soft” in project management research. This categorization is becoming more increasingly used in project management research for example by stating that some projects are “hard”, while other projects are “soft”, that some project skills are “hard”, while other project skills are “soft” etc. The aim is to discuss this dichotomization as an example of hierarchization – a power struggle between opposites – within project management research and literature and acknowledge the effects for project management research and practice of unreflective upholding of this dichotomy. We provide a critical review and discussion of stage-gate models as an example of “hard” project management approaches, and agile methods as an example of “soft” approaches to project management and acknowledge that in project management practice, it seems as if “hard” and “soft” approaches are most often combined. Hence, this dichotomy seems to be upheld by the research community while practitioners show a more holistic perspective to project management.     

Spatial and temporal dynamics of suspended load at-a-cross-section: the lowermost Ebro River (Catalonia, Spain)

Suspended load dynamics were analyzed for the period 2007-2009 in a semi-meandering cross-section under different hydrological conditions. Samples were collected at four different points of the cross-section. During “low discharges” (≤600 m³/s) suspended load samples were collected at-a-monthly basis, whereas at “high discharges” (>600 m³/s) sampling was conducted intensively (at-a-daily basis during the first stages of the flood event). Results indicated that during low discharges, both organic and inorganic suspended load concentrations tended to be uniformly distributed across the fluvial section; but during high discharges, two distinct areas were found: an area extending from the “Inner-bank” to the “Channel centre” (Area-I) with higher suspended concentrations (organic and inorganic) than those recorded in the “Outer bank” (Area-II). This phenomenon was likely related to the formation of secondary flow velocity cells and the activation of new sources of sediment. In addition, a non-significant relationship between organic suspended load and water flow was observed in the outer-bank. At-a-monthly basis, the analysis of the suspended load showed the existence of an intra-annual cycle of the inorganic concentrations, with a progressive increase from October to March followed by a decrease from March to September. Nevertheless, the organic suspended load did not show any trend, being equally distributed along the year, suggesting that other sources of organic matter besides phytoplankton are predominant.     

Adapting aspects of GBTool 2005—searching for suitability in Taiwan

One of the main areas of activity in the concept of Sustainable Building (SB) is the development of methods and tools used to assess the environmental performance of buildings. GBTool is the software implementation of the Green Building Challenge (GBC) assessment method, which has been under development since 1996 by International Initiative for a Sustainable Built Environment (iiSBE) and participating teams from more than 20 countries. The method also places emphasis on the ability of local users to adjust the system to suit regional technical and cultural issues. This study seeks to explore regional customization of GBTool2005. That is, we will utilize the AHP method to investigate the priority of the so-called “Issues” and “Categories” of the GBTool2005, by compiling and completing an experts’ questionnaire. This questionnaire is aimed at proposing a separate set of feasible weightings for Issues and Categories of GBTool2005 by the AHP method, and to present the “critical” assessment factor for Taiwan.     

Systems Engineering to improve the governance in complex project environments

Projects delivered in complex environments are often late, over-budget and provide fewer benefits than what were originally expected. Systems Engineering is the emerging paradigm in complex project environments to transform the governance from “project based” to “system based” and thereby increase the chance of holistic success. Systems Engineering is a multidisciplinary approach to enable the successful delivery of systems in complex environments through a comprehensive set of approaches, techniques and tools, initially developed in the USA after the Second World War. This paper focuses on how Systems Engineering can transform the governance from “project governance” to “system governance”, improving the performance of projects delivered in a complex environment. This paper presents Systems Engineering tools and techniques focusing, in particular, on the most relevant for project management, project governance and stakeholder management. At the end it provides a rich research agenda for further studies.     

Observations on FORM in a simple geomechanics example

This technical note studies the First Order Reliability Method (FORM) applied to a plane strain Mohr-Coulomb drained (c′, tan ?′) element test. The influences of distribution types and linear correlation between random variables are studied. The approximation of assuming a “first order” limit state function is assessed by comparison with direct integration of the probability distribution function in the failure region. The results indicate that FORM overestimates p_f when random variables are lognormally distributed and underestimate p_f when random variables are normally distributed.     

Elemental composition and oxidative properties of PM2.5 in Estonia in relation to origin of air masses — results from the ECRHS II in Tartu

Fine particulate matter (PM_2.5) was sampled at an urban background site in Tartu, Estonia over one-year period during the ECRHS II study. The elemental composition of 71 PM_2.5 samples was analyzed for different chemical elements using energy-dispersive X-ray fluorescence spectrometry (ED-XRF). The oxidative activity of 36 samples was assessed by measuring their ability to generate hydroxyl radicals in the presence of hydrogen peroxide.The origin of air masses was determined by computing 96-hour back trajectories of air masses with the HYSPLIT Model. The trajectories of air masses were divided into four sectors according to geographical patterns: “Russia,” “Eastern Europe,” “Western Europe,” and “Scandinavia.”During the study period, approximately 30% of air masses originated from “Scandinavia.” The other three sectors had slightly lower values (between 18 and 22%). In spring, summer, and winter, higher total PM levels originated from air masses from continental areas, namely “Russia” and “Eastern Europe” (18.51 ± 7.33 and 19.96 ± 9.23 µg m^− 3, respectively). In autumn, the PM levels were highest in “Western Europe”. High levels of Fe, Ti, and AlCaSi (Al, Ca, and Si) were also detected in air masses from the Eurasian continent. The oxidative properties were correlated to the origin of air masses. The ⋅OH values were approximately 1.5 times higher when air masses originated from the direction of “Eastern Europe” or “Russia.”The origin of measured particles was evaluated using principal component factor analysis. When comparing the PM_2.5 elemental composition with seasonal variation, factor scores, and other studies, the factors represent: (1) combustion of biomass; (2) crustal dust; (3) traffic; and (4) power plants and industrial processes associated with oil burning.The total PM_2.5 is driven mainly by biomass and industrial combustion (63%) and other unidentified sources (23%). Other sources of PM, such as crustal dust and traffic, contribute a total of 13%.     

Optimising the installation costs of renewable energy technologies in buildings: A Linear Programming approach

This paper demonstrates how Linear Programming (LP) can be applied to assist in the choice of renewable energy technologies for use in buildings to meet CO₂ emissions reduction targets. Since there are many possibilities for combining different renewable technologies, the capital costs associated with the installation of one or more renewables can vary widely. In terms of capital investment the preferred solution will be the one at least cost, and LP provides an effective way to find this minimum through the so-called “objective function”. This project has used “lp_solve”, a free-source Mixed Integer Linear Programming solver that has been embedded in a Microsoft Excel application called Carbon emissions And Renewables for Building OPtimisation Toolkit (CARB-OPT) developed by RES Ltd in collaboration with London South Bank University (Renewable Environmental Services Ltd. (RES) is the environmental consultancy of Long and Partners Engineering Group. RES is currently involved in a Knowledge Transfer Partnerships (KTP) project in conjunction with the Faculty of Engineering, Science and the Building Environment (ESBE) at London South Bank University). This paper reports the application of this LP optimisation process for an office building case study with four alternative combinations of renewables. The process showed the technology mix that would lead to the smallest investment needed to comply with UK Building Regulations requirements and regional planning targets. In addition, the process offers a robust methodology to test the impact that the key assumptions may have upon the optimum solution.     

A critical analysis of recent advances in the techniques for the evaluation of renewable energy projects

Renewable energy investment is an integral part of sustainable economic development agenda. Whereas some important advances have been made in recent years to assist project investors in making better use of financial risk management instruments and taking into consideration real options embedded in renewable energy projects, this research asserts that, owing to failure to consider both behavioural uncertainty and the limit of risk transfer, these approaches may still lead to a biased evaluation result. Drawing on a novel concept of “risk-bearing capacity”, the research suggests developing a new approach whereby investors can incorporate the choice of financial protection measures into investment evaluation in a coherent way.     

Determination of bioclimatic comfort in three different land uses in the city of Erzurum,Turkey

This study was carried out to determine the human bioclimatic conditions in rural, urban and urban forest areas in the conditions of the city of Erzurum, where an extreme continental climate type prevails. Data were obtained over a 10-month period and human bioclimatic conditions in these three different land-use types were evaluated using human bioclimatic indices, suitable for the data obtained. In the study, thermohygrometric index (THI), which assesses air temperature and relative humidity, and “beer garden days” index, which uses the days when temperature at 21:00 is over 20 °C, were used. While in these three areas “hot” and “comfort” ranges were determined to be 10% of the period, the number of “beer garden” days was only 20 days in rural, 15 days in urban forest and 18 days in urban areas of Erzurum. Consequently, it has been determined that the most suitable area for the human comfort in the conditions of Erzurum is in the urban area which is followed by the urban forest and the rural areas, both for each observation time and across the whole period.     

Defining relational contracting from the Wittgenstein family-resemblance philosophy

There has been an increasing interest in the concept of relational contracting (RC) in construction starting from the late 1990s. RC embraces and underpins different forms of collaborative approaches, including partnering, alliancing, joint venture and other collaborative working arrangements and better risk sharing mechanisms. By applying Nyström's and Yeung et al.'s similar approaches to define construction partnering and construction alliancing respectively, this paper focuses on RC and family-resemblance. A significant contribution to new knowledge is believed to have been made in providing a concise and comprehensive approach in defining the similar and yet different key components of RC by using a Sunflower Model. The development of this innovative Model is based on the German philosopher, Ludwig Wittgenstein's family-resemblance philosophy. His idea is that a complex concept can be understood as a network of overlapping similarities. Based on the reported literature, it is concluded that there are always five core elements included in construction RC. They are “commitment”, “trust”, “cooperation and communication”, “common goals and objective”, and “win–win philosophy”. In addition to these core elements, a number of different non-core elements, or called petals, can be added to constitute a specific variant of RC in construction. The contribution can be of paramount importance to both the research community and the construction industry. By using this innovative theoretical framework to define construction RC, industrial practitioners may find the Sunflower Model useful in the procurement of a construction RC project. The Sunflower Model can be applied to explain the underlying concepts and as a common starting point for discussions between a client and a contractor on how to procure a RC project, thus avoiding any misinterpretations of what a RC project is.     

An investigation of the existing situation and trends in building energy efficiency management in China

According to the Chinese State Council's “Building Energy Efficiency Management Ordinance”, a large-scale investigation of energy efficiency (EE) in buildings in contemporary China has been carried out in 22 provincial capitals and major cities in China. The aim of this project is to provide reliable information for drawing up the “Decision on reinforcing building energy efficiency” by the Ministry of Construction of China. The surveyed organizations include government departments, research institutions, property developers, design institutions, construction companies, construction consultancy services companies, facility management departments, financial institutions and those which relate to the business of building energy efficiency. In addition, representatives of the media and residents were also involved. A detailed analysis of the results of the investigation concerning aspects of the current situation and trends in building energy consumption, energy efficiency strategy and the implementation of energy efficiency measures has been conducted. The investigation supplies essential information to formulate the market entrance policy for new buildings and the refurbishment policy for existing buildings to encourage the development of energy efficient technology.     

A life-cycle energy analysis of building materials in the Negev desert

Environmental quality has become increasingly affected by the built environment—as ultimately, buildings are responsible for the bulk of energy consumption and resultant atmospheric emissions in many countries. In recognizing this trend, research into building energy-efficiency has focused mainly on the energy required for a building's ongoing use, while the energy “embodied” in its production is often overlooked. Such an approach has led in recent years to strategies which improve a building's thermal performance, but which rely on high embodied-energy (EE) materials and products. Although assessment methods and databases have developed in recent years, the actual EE intensity for a given material may be highly dependent on local technologies and transportation distances. The objective of this study is to identify building materials which may optimize a building's energy requirements over its entire life cycle, by analyzing both embodied and operational energy consumption in a climatically responsive building in the Negev desert region of southern Israel—comparing its actual material composition with a number of possible alternatives. It was found that the embodied energy of the building accounts for some 60% of the overall life-cycle energy consumption, which could be reduced significantly by using “alternative” wall infill materials. The cumulative energy saved over a 50-year life cycle by this material substitution is on the order of 20%. While the studied wall systems (mass, insulation and finish materials) represent a significant portion of the initial EE of the building, the concrete structure (columns, beams, floor and ceiling slabs) on average constitutes about 50% of the building's pre-use phase energy.     

人本需求视角下基于乡镇单元主导功能的 特大城市半城市化地区生态系统服务优化 研究——以上海为例

已有对城市生态系统服务功能优化的研究通常是"供给"导向下的增量研究,很少考虑到当地的人类价值取向变化下的实际需求对生态系统造成的负面效应,这些当地"需求"的负面效应直接影响城市生态系统服务提供的"供给"效益质量,使其在空间地域上的"供给-需求"错位、失衡,造成地方规划管理上的被动性和盲目性,这一现象在生态用地和建设用地交错的特大城市郊区的半城市化地区最为显著。以上海为例,探讨基于人本需求的特大城市半城市化地区生态系统服务主导功能优化思路;以乡镇街道为基本单元对半城市化地区进行解构,评价其供给、调节、支持、文化娱乐游憩等生态系统服务的功能现状,通过人本需求视角的聚类分析定位乡镇单元的生态主导功能,并据此提出生态系统服务的优化思路;旨在通过支持空间规划决策来有效控制半城市化的负面效应,使局部单元的生态服务价值优化与总体城市生态系统服务提升的目标达成一致。