Assessment of innovative ventilation in the framework of the EPBD—A probabilistic approach: RESHYVENT project

The market uptake of innovative, energy efficient concepts in the building sector is to a large extent influenced by the stimuli found in building regulations. The Energy Performance of Buildings Directive (EPBD) makes the application of an EPB regulation mandatory for new buildings and for major renovations. If one is obliged to make an assessment of buildings in terms of energy performance, it is clear that one should be able to assess all kinds of building designs and of technologies. However, the EPB regulations (present or under development) clearly not cover all possible technologies. Among the technologies that are typically not covered by the standard procedures are innovative ventilation concepts, e.g. hybrid ventilation in dwellings. This paper wants to highlight the need for the development of a coherent approach, based on a mixture of European measures and national actions.     

Concentration of virus from water by osmotic ultrafiltration—II: Mass transport aspects

A membrane process is described which allows water samples to be concentrated by factors of 400 or more, without loss of viral infectivity. The requirements for effecting high ratios of initial to final volumes are examined in terms of two methods of solving the coupled transport equations. Initial volumes, membrane area, membrane transport coefficients, and osmotic coefficients are related to predict the rate and extent of concentration which can be achieved. The methods of characterizing membrane parameters to predict water transport rates are discussed. Experimental results are compared with computer predicted rates, using the two types of mathematical solutions.     

Recent progress on passive cooling techniques: Advanced technological developments to improve survivability levels in low-income households

Low-income households in developed and less developed countries suffer from serious indoor environmental problems such as heat stress, lack of comfort and poor indoor air quality. Passive cooling of buildings and in particular solar and heat protection techniques, heat dissipation and heat amortisation techniques have reached a very high degree of maturity. New technological developments have proven extremely efficient in decreasing the need for cooling and improving indoor environmental conditions. Developments on the field of solar and heat protection, such as highly reflective coatings for the urban environment and the building envelope and new knowledge and developments on the field of ground and convective cooling and ventilation, may help low-income citizens to considerably improve their quality of life during the overheating period. These new developments are characterised by low cost and are easy to apply.     

Building simulation as an assisting tool in decision making: Case study: With or without a double-skin façade?

Implementation of double-skin façades in buildings has been an object of broad application in the recent years. In this presentation, a planned office building in the city-centre of Trondheim, Norway, is used as a case for considering whether a double-skin should be applied to the east façade in order to reduce the heating demand, thus making the double-skin façade a profitable investment. The building is modeled both with and without a double-skin façade with the building energy simulation program ESP-r. This paper describes how a double-skin façade with controllable windows and hatches for natural ventilation can be implemented in the simulation program. The simulation results indicate that the energy demand for heating is about 20% higher for the single-skin façade with the basic window solution compared to the double-skin alternative. However, by switching to windows with an improved U-value in the single-skin alternative, the difference in energy demand is almost evened out. The number of hours with excessive temperatures is, in contrast to other studies on the subject, not significantly higher for the double-skin alternative. However, the predicted energy savings are not sufficient to make the application of a double-skin façade profitable.     

Comparative environmental assessment of wood transport models: A case study of a Swedish pulp mill

Wood transportation from forest landing to forest-based industries uses large amounts of energy. In the case of Sweden, where forest operations are highly and efficiently mechanized, this stage consumes more fossil fuels than other elements of the wood supply chain (such as silviculture and logging operations). This paper intends to compare the environmental burdens associated to different wood transport models considering a Swedish pulp mill as a case study by using Life Cycle Assessment (LCA) as an analytical tool.Five scenarios (the current one and four alternative reliable scenarios) were proposed and analysed taking into account two variables. On the one hand, the influence of imported pulpwood share from Baltic countries and on the other hand, the use of rail transportation for wood transport. In particular, the following impact categories were assessed: Eutrophication, Global Warming, Photochemical Oxidant Formation, Acidification and Fossil fuel extraction. The environmental results indicate that transport alternatives including electric and diesel trains, as well as the reduction in Baltic wood imports should present better environmental performance than the current scenario in terms of all the impact categories under study. Remarkable differences were identified with regard to energy requirements. This divergence is related to different long-distance transport strategies (lorry, boat and/or train) as well as the relative import of wood selected.The combination of lorry and train in wood transportation from Southern Sweden plus the reduction of wood imports from 25% to 15% seems to be more favourable from an environmental perspective. The results obtained allow forecasting the importance of the wood transport strategy in the wood supply chain in LCA of forest products and the influence of energy requirements in the results.     

Heat supply to low-energy buildings in district heating areas: Analyses of CO2 emissions and electricity supply security

In several housing development projects in Norway the requirements related to the mandatory connection to district heating plants have shown to be a barrier for building low-energy residential buildings. The developers have considered the costs related to both low-energy measures and a space heating system that can utilize district heat to be too high to give the project acceptable profitability. In these projects the developers wanted to use a cheaper electric space heating system. Based on models representative for the range of the Norwegian district heating plants, calculations show that the CO₂ emissions related to heating in residential buildings with an energy standard in accordance with the new building regulations and that are connected to the district heating grid, are lower than for similar buildings with a low-energy standard and with heating based on electricity. However, in a long term perspective the differences are marginal when considering the national annual CO₂ emissions. Similarly, increased peak power demand due to electricity-based heating may also be regarded as marginal when compared to the present maximum peak power capacity in Norway.     

Development of sustainable urban forms for high-density low-income Asian countries: The case of Vietnam: The institutional hindrance of the commons and anticommons

Urban development with sustainable urban forms in high-density low-income Asian countries is a great challenge in the context of acute land scarcity. Though the model of compact cities is a natural choice for high-density urbanizing Asia, fierce competition for limited urban land resources without effective governance often results in an unfavorable form of densification and urban compaction. From the perspective of land rights, this problematic urban form is generated in the presence of the anticommons and commons. The co-existence of the anticommons and the commons results in the under-utilization of scarce land resources and over-consumption of scarce environmental amenities, and the combination of the two constitutes a mechanism that induces a vicious cycle continuously degenerating urban environment, reducing social equity, and locking the city in an unsustainable form which exacerbates housing shortages and land scarcity. The case study of Vietnam has demonstrated that state capacity and governance should be the key factors for the city development in a sustainable urban form, as market failures of the anticommons and commons are caused by state failures.     

Do people like to feel ‘neutral’?: Exploring the variation of the desired thermal sensation on the ASHRAE scale

This analysis explores the pattern of variation of the desired thermal sensation on the ASHRAE scale, applying the method of direct enquiry. Data are from studies of thermal comfort at university lectures and in selected dwellings. Respondents reported both their thermal sensation and the sensation they would have desired at that time. The data contain 868 comparisons of the actual and the desired sensation. On 57% of occasions the desired sensation was other than ‘neutral’. The respondents did not always desire the same sensation, and the mean desired sensation differed systematically among the respondents. The mean desired sensation depended to some extent on the actual sensation, there being a positive correlation in the region from ‘neutral’ and ‘warm’ and a negative correlation outside this region. Sensations on the ASHRAE scale are shown to have more than one meaning. Adjusting the ASHRAE scale to allow for the desired sensation yields different distributions of thermal comfort and different group-optimum temperatures. The adjustment should therefore be applied whenever the ASHRAE scale is used. The implications for thermal simulation and for energy use in buildings are considered.     

Natural disaster risk in Asian megacities: A case for risk pooling?

This paper examines the characteristics of natural disaster risk in the context of megacities generally, and Asian megacities particularly. A key gap in approaches to managing megacity risk has been attention to the financial aspects, for which interest has lately been emerging in terms of exploring whether such risk may be suitable for a donor-assisted regional Asian risk pooling scheme. One suggestion concerns insuring public sector liabilities in terms of infrastructure replacement funding, liquidity support and relief to the population. Recently, this was operationalized in the Caribbean regional pooling of hurricane and earthquake risks, and by the Mexican government for earthquake risks. In both cases, central governments are the actors. We assess the rationale and applicability of such deliberations given the dynamic nature of vulnerability and risk, and discuss conditions for conducting similar transactions for Asian megacity risks. Overall, given our adopted criteria, we tentatively conclude that there may indeed be a case for risk pooling, yet the dynamics of assessing formal and informal risks as well as the specificity of conditions in respective megacities pose important hurdles that have to be overcome.     

Resistance of headed studs subjected to fatigue loading: Part I: Experimental study

In steel-concrete composite structures the transfer of longitudinal shear forces at the interface between steel and concrete is mostly realized by headed shear studs. Especially in bridges due to traffic loads these shear connectors are subjected to high-cycle loading and the fatigue resistance governs the design. In this first part of two companion papers a series of experimental work with standard EC4 push-out specimens is presented. The main purpose of these tests was to determine the fatigue life and a possible reduction of the static strength of the headed shear studs subjected to unidirectional cyclic loading. A further aspect was to examine the effects of the loading sequence and damage accumulation on the fatigue life. The results of the experimental investigations show that due to a crack initiation at the stud foot at 10%-15% of the fatigue life, an early reduction of the static strength is caused. Furthermore tests to examine the effects of the loading sequence on the fatigue life revealed that the linear damage accumulation hypothesis according to Palmgren and Miner on which the present design codes are based do not describe the real behaviour.     

Phthalate removal throughout wastewater treatment plant: Case study of Marne Aval station (France)

The fate of six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) was investigated throughout wastewater treatment processes in the wastewater treatment plant (WWTP) of Marne Aval (France). That plant treats wastewater from a highly populated area and was used as a pilot station for development of nitrification processes.In wastewater, at each step of treatment, DEHP was always the major compound (9 to 44 µg L^− 1), followed by DEP (1.6 to 25 µg L^− 1). Other phthalates averaged 1 µg L^− 1 and DnOP remained close to the detection limit in nearly all cases.In sludge, the prevailing compound was also DEHP (72 µg g^− 1) which is consistent with its tendency to get sorbed upon suspended matter (SM). DnOP came in third, in relation with its resistance to biodegradation.For the studied period, the removal efficiency of DEHP from wastewater was about 78%. That removal seemed to proceed rather from particle settling than from biodegradation. A highly significant correlation (p < 0.001) was found between DEHP and SM concentrations throughout treatment processes. The other compounds: DMP, DEP, DnBP and BBP, displayed satisfactory efficiencies ranging from 68 to over 96% for the lighter ones obviously more easily degraded.Under rainy periods, the plant discharge impact upon Marne River quality in terms of phthalate fluxes, appeared to be minor as compared to the amount brought by the storm overflows in the same area. Downstream of the WWTP discharge, DEHP concentration remained under the European norm for surface water (NQE: 1.3 µg L^− 1).Our study documents the behaviour of phthalate esters throughout a WWTP which treatment device is used by 55% of the WWTP in the river Seine basin.     

计算机模拟在建筑节能设计中的应用

依据DBJ13—62—2004《福建省居住建筑节能设计标准实施细则》,从节能率、成本、建筑热舒适性、节能方案适宜性等方面对比分析了规定性指标节能设计法与动态权衡计算设计法的优劣。得出计算机仿真模拟技术在建筑节能设计中应用的重要性。