Estimates of the energy impact of ventilation and associated financial expenditures

Ventilation is essential for the maintenance of good indoor air quality, although there is evidence to suggest that energy loss through uncontrolled or unnecessary air infiltration is excessive. In this study, estimates are presented for air change (ventilation and infiltration) energy use in non-industrial buildings for 13 countries. Various methods are used for the estimates, but they are mainly based on calculating the total annual enthalpy change needed for the conditioning of air. The potential for reduced energy use by improved ventilation control is also briefly reviewed. Considering the non-industrial building stock of the 13 countries collectively, the total annual loss of heating energy due to air change is estimated to amount to 48% of delivered space conditioning energy (including heating equipment losses). The results emphasise that air change related energy losses are as important as conduction and equipment losses (including ‘flue’ losses) in dissipating delivered space conditioning energy from buildings.In addition, estimated financial expenditures, as well as carbon dioxide emissions associated with this energy use are indicated. The financial expenditures are derived from the air change energy estimates using published International Energy Agency (IEA) energy pricing information. The magnitudes of the carbon dioxide emissions have been based on published IEA estimates of total emissions from energy-related sources for each country.     

低碳建筑设计理念与技术

针对全球气候环境日益变暖和我国建筑二氧化碳排放量比例居高形势,该文提出低碳建筑将成为建筑界的永恒课题。对低碳建筑概念进行阐述,提出自然采光与自然通风设计和太阳能得热空间与温度梯度场房间设计的低碳建筑设计理念;剖析低碳建筑技术的利用,并试算三例住宅在使用过程中二氧化碳排放量,指出要实现整个寿命周期的低碳建筑,不仅只是实现建筑使用期间的低碳,还需要从材料的生产和建造、维护与更新、拆除和重新利用等这些方面充分考虑降低能耗和二氧化碳的排放。     

Energy and carbon dioxide implications of building construction

This paper investigates the amount of energy required to construct buildings, and the resulting carbon dioxide emissions to the atmosphere from the fossil fuel components of that energy. Energy requirements and carbon dioxide emissions are compared for typical commercial, industrial and residential buildings, using New Zealand as an example. A modest change from concrete and steel to more wood construction could lead to a substantial reduction in energy requirements and carbon dioxide emissions, but the sustainability of such a change has significant forestry implications.     

Climate change adaptation pathways for Australian residential buildings

Climate change can significantly impact on the total energy consumption and greenhouse gas (GHG) emissions of residential buildings. Therefore, climate adaptation should be properly considered in both building design and operation stages to reduce the impact. This paper identified the potential adaptation pathways for existing and new residential buildings, by enhancing their adaptive capacity to accommodate the impact and maintain total energy consumption and GHG emissions no more than the current level in the period of their service life. The feasibility of adaptations was demonstrated by building energy simulations using both representative existing and new housing in eight climate zones varying from cold, temperate to hot humid in Australia. It was found that, in heating dominated climates, a proper level of adaptive capacity of residential buildings could be achieved simply by improving the energy efficiency of building envelop. However, in cooling dominated regions, it could only be achieved by introducing additional measures, such as the use of high energy efficient (EE) appliances and the adoption of renewable energy. The initial costs to implement the adaptations were assessed, suggesting that it is more cost-effective to accommodate future climate change impacts for existing and new houses by improving building envelop energy efficiency in cooling dominated regions, but installing on-site solar PVs instead in heating and cooling balanced regions.     

Bautechnisch‐bauphysikalische Beurteilung der Wirksamkeit energetischer Sanierungen am Beispiel städtischer Wohnhausanlagen in Wien

Study on the efficiency of thermal refurbishment of residential buildings in Vienna. In the framework of the Kyoto Protocol Austria has committed to reduce its greenhouse gas emissions until 2008/2012 by 13% on the base of 1990. Therefore the Federal Government as well as the provincial governments have implemented programs for the protection of climate including several measures to reduce the emission of hazardous greenhouse gases mainly CO₂. Regarding the enormous potential reduction activities were mainly focused on residential buildings. The refurbishment of the building envelope reduces the heating costs as well as the carbon dioxide emissions and improves the indoor climate. Several investigations were taken to check the utility of thermal refurbishment under structural and physical conditions. Plenty of data available in the line of several expertises of existing residential buildings were analysed and completed by additional investigations. The economic efficiency of thermal insulations is pointed out as well as the period of repayment or the influence of the thickness of insulation on the heating energy demand or possible CO₂‐reductions.     

Examining and quantifying the drivers behind alterations and extensions to commercial buildings in a central business district

The drive to undertake building adaptation has increased in momentum, the primary reason being adaptation can be less expensive than new build and conventionally result in faster project delivery times. The issue of sustainable development is another clear driver for adaptation and collectively buildings contribute around half of all greenhouse gas emissions. At the same time governments seek effective and efficient ways of reducing the contribution of cities to climate change and building adaptation appears to offer a practical means of reducing building-related emissions. One example is the ‘1200 building program’ which aims to increase adaptation rates with a target of 1200 city centre office adaptations by 2020 as part of the strategy to achieve carbon neutrality. Through a longitudinal examination of building adaptations it is possible to identify the nature and extent of typical levels of adaptation, as well as determining the inter-relationship between different types of adaptation and building attributes. Melbourne city centre was used for a case study which analysed 5290 building adaptation events between 1998 and 2008. The findings promote the adaptive reuse of buildings in specific circumstances and are directly applicable for increasing sustainability in the built environment. The case study focused on existing buildings in a global city to ensure relevance to urban centres where existing commercial buildings can become part of the solution to mitigate climate change.     

Towards global benchmarking for sustainable homes: an international comparison of the energy performance of housing

Over the past 15 years, house building standards across the western world have begun to address ecologically sustainable development (ESD) principles. Amongst the range of environmental sustainability issues arising from housing construction and occupation, the energy demand for heating and/or cooling to maintain thermal comfort has the longest history and is most widespread in policy and regulation. Since energy in our homes is mainly fossil-derived, a key issue is global climate change impacts. Since greenhouse gas emissions can be emitted in various locations across the globe with similar results, it follows that a given greenhouse gas emission arising from residential space heating and cooling has approximately equal impact, irrespective of the location of the building. These emissions are therefore an appropriate candidate for benchmarking internationally, yet there have been few attempts to undertake this activity. This paper reports on a study undertaken in Australia which compares the thermal energy performance of housing in the United States, Canada, UK and Australia. The comparison is based on energy ratings of over 50 house designs from the comparison countries. Each design was assessed as being current and verified as complying with rather than significantly exceeding local regulatory requirements. Issues in design of both the buildings and the modelling tool used are highlighted, and the results are presented. Conclusions are drawn on the reasons for wide variations in thermal energy performance, the implications for benchmarking, and the case for globally consistent housing environmental performance policies and regulation.     

从澳大利亚绿色建筑实施现状看中国绿色建筑的未来

全球气候变化已经凸显,对人类的生产生活造成了巨大的影响,节能减排刻不容缓.建筑物的温室气体排放较高,涉及范围较广.世界各国需要推行绿色建筑,节能减排.以澳大利亚和中国的绿色建筑评价标准为出发点,重点研究两国各个部门在绿色建筑政策方面的推行情况.     

Urban climate change mitigation and adaptation planning: Are Italian cities ready?

Climate Action Planning is one of the top priorities of cities in order to reduce greenhouse gas emissions and strengthening climate-resilience, as pointed out by the New Urban Agenda and the Paris Agreement.This study aims at assessing the development of climate change mitigation and adaptation planning in Italian cities. To this end, we analysed the availability of Local Climate Plans (LCPs) in 76 cities, which are included in the Eurostat Urban Audit (UA-2015) database. In a further step, we analysed the content of the urban climate change mitigation and adaptation plans available in a smaller sample of 32 Italian cities of 2007 Eurostat Urban Audit database (UA-3), looking at the single actions undertaken for addressing mitigation and adaptation to climate change. Results show the almost total absence of comprehensive and stand-alone urban climate change adaptation plans in Italy (except for two cities, Ancona and Bologna), whereas we found that in 61 out of 76 cities municipal civil protection plans are the instruments that deal with local emergencies associated to extreme weather events. On the other hand, 56 out of 76 urban climate change mitigation plans (i.e. Sustainable Energy Action Plans) are being developed in the framework of the Covenant of Mayors, which is a transnational network of local governments created by the European Union (EU) in 2012. The results obtained on the mitigation side point out that, in absence of a national law that imposes Italian cities to develop LCPs, transnational networks are an effective boost to voluntary commitment to reach EU climate and energy objectives.     

Uncertainty and sensitivity analysis of building performance using probabilistic climate projections: A UK case study

This study explores the uncertainties and sensitivities in the prediction of the thermal performance of buildings under climate change. This type of analysis is key to the assessment of the adaptability and resilience of buildings to changing climate conditions. The paper presents a comprehensive overview of the key methodological steps needed for a probabilistic prediction of building performance in the long term future (50 to 80 years). The approach propagates uncertainties in climate change predictions as well as the uncertainties related to interventions in building fabric and systems.A case study focussing on an air-conditioned university building at the campus of the authors is presented in order to demonstrate the methodology. This employs the most recent probabilistic climate change projections for the United Kingdom (UKCP09 dataset) and takes into account facility management uncertainties when exploring uncertainties in the prediction of heating energy, cooling energy, and carbon emissions.     

为适应气候而建造:被动式建筑

以二氧化碳为代表的温室气体,导致地球不断变暖。应对气候变化、倡导低碳生活已经成为了全人类的共识。在这种共识下,被动式建筑成为继绿色建筑、低碳建筑、可持续建筑等之后备受社会各界关注的热点之一。从被动式建筑概念的提出入手,比较分析了被动式建筑与绿色建筑、节能建筑、低碳建筑、可持续建筑等概念之间的异同,指出被动式建筑是实现上述其他类型建筑的根本途径和方法。在此基础上,介绍了德国、美国及日本被动式建筑的实践,并分析了被动式建筑在我国的应用前景。     

Identification of key factors for uncertainty in the prediction of the thermal performance of an office building under climate change

There is growing concern about the potential impact of climate change on the thermal performance of buildings. Building simulation is well-suited to predict the behaviour of buildings in the future, and to quantify the risks for prime building functions like occupant productivity, occupant health, or energy use. However, on the time scales that are involved with climate change, different factors introduce uncertainties into the predictions: apart from uncertainties in the climate conditions forecast, factors like change of use, trends in electronic equipment and lighting, as well as building refurbishment / renovation and HVAC (heating, ventilation, and air conditioning) system upgrades need to be taken into account. This article presents the application of two-dimensional Monte Carlo analysis to an EnergyPlus model of an office building to identify the key factors for uncertainty in the prediction of overheating and energy use for the time horizons of 2020, 2050 and 2080. The office has mixed-mode ventilation and indirect evaporative cooling, and is studied using the UKCIP02 climate change scenarios. The results show that regarding the uncertainty in predicted heating energy, the dominant input factors are infiltration, lighting gain and equipment gain. For cooling energy and overheating the dominant factors for 2020 and 2050 are lighting gain and equipment gain, but with climate prediction becoming the one dominant factor for 2080. These factors will be the subject of further research by means of expert panel sessions, which will be used to gain a higher resolution of critical building simulation input.     

Estimating the impacts of climate change and urbanization on building performance

Over the past 15 years, much scientific work has been published on the potential human impacts on climates. For their Third Assessment Report in 2001, the United Nations International Programme on Climate Change developed a set of economic development scenarios, which were then run with the four major general circulation models (GCM) to estimate the anthropogenesis-forced climate change. These GCMs produce worldwide grids of predicted monthly temperature, cloud, and precipitation deviations from the period 1961–1990. As this period is the same used for several major typical meteorological year data sets, these typical data sets can be used as a starting point for modifying weather files to represent predicted climate change. Over the past 50 years, studies of urban heat islands (UHI) or urbanization have provided detailed measurements of the diurnal and seasonal patterns and differences between urban and rural climatic conditions. While heat islands have been shown to be a function of both population and microclimatic and site conditions, they can be generalized into a predictable diurnal and seasonal pattern. Although the scientific literature is full of studies looking at the impact of climate change driven by human activity, there is very little research on the impact of climate change or urban heat islands on building operation and performance across the world. This article presents the methodology used to create weather files which represent climate change scenarios in 2100 and heat island impacts today. For this study, typical and extreme meteorological weather data were created for 25 locations (20 climate regions) to represent a range of predicted climate change and heat island scenarios for building simulation. Then prototypical small office buildings were created to represent typical, good, and low-energy practices around the world. The simulation results for these prototype buildings provide a snapshot view of the potential impacts of the set of climate scenarios on building performance. This includes location-specific building response, such as fuel swapping as heating and cooling ratios change, impacts on environmental emissions, impacts on equipment use and longevity comfort issues, and how low-energy building design incorporating renewables can significantly mitigate any potential climate variation. In this article, examples of how heat island and climate change scenarios affect diurnal patterns are presented as well as the annual energy performance impacts for three of the 25 locations. In cold climates, the net change to annual energy use due to climate change will be positive – reducing energy use on the order of 10% or more. For tropical climates, buildings will see an increase in overall energy use due to climate change, with some months increasing by more than 20% from current conditions. Temperate, mid-latitude climates will see the largest change but it will be a swapping from heating to cooling, including a significant reduction of 25% or more in heating energy and up to 15% increase in cooling energy. Buildings which are built to current standards such as ASHRAE/IESNA Standard 90.1-2004 will still see significant increases in energy demand over the twenty-first century. Low-energy buildings designed to minimize energy use will be the least affected, with impacts in the range of 5–10%. Unless the way buildings are designed, built, and operated changes significantly over the next decades, buildings will see substantial operating cost increases and possible disruptions in an already strained energy supply system.     

Environmental performance of a naturally ventilated city centre library

To tackle climate change it is essential to reduce carbon dioxide emissions. To this end, it is important to reduce the energy demands of non-domestic buildings. Naturally ventilated buildings can have low energy demands but the strategy is difficult to implement in deep plan, urban locations. The Frederick Lanchester Library at Coventry University, UK, incorporates natural ventilation, daylighting and passive cooling strategies. By using lightwells and perimeter stacks to supply and exhaust air, it can be ventilated by natural means despite its deep plan form and sealed façade. This paper describes the building and presents the energy consumption and the internal temperatures and CO₂ levels recorded in 2004/2005. The building's performance is compared to the original design criteria and good practice guidelines. Recommendations for the design of such buildings are made and the likely performance in other UK cities is assessed. It is concluded that the building uses under half the energy of a standard air-conditioned building and yet, in summer, can keep the interior comfortable and up to 5 °C below ambient. The design would perform equally well in the typical weather conditions experienced at 13 other UK cities, but not in London. It is concluded that deep-plan, naturally ventilated buildings with sealed facades, if well designed, could maintain thermal comfort in all but a very few UK locations, whilst consuming much less energy than even good practice standards.     

对建筑楼宇碳排放量计算模型的探索

对建筑楼宇碳排放量的计算模型进行研究,将有助于评估建筑楼宇整个生命周期对环境的影响。本文对建筑的整个生命周期中各个阶段的二氧化碳排放量进行了探索,通过对建筑物材料及所耗能源数据进行收集与分析,获得不同建筑材料及能源碳排放系数。在前人研究的基础上,建立建筑物碳排放量的计算模型。通过案例分析,得到建筑使用和维护阶段中的碳排放量占到全生命周期的比例最大的结论。     

Calculation of the yearly energy performance of heating systems based on the European Building Energy Directive and related CEN standards

According to the Energy Performance of Buildings Directive (EPBD) all new European buildings (residential, commercial, industrial, etc.) must since 2006 have an energy declaration based on the calculated energy performance of the building, including heating, ventilating, cooling and lighting systems. This energy declaration must refer to the primary energy or CO₂ emissions.The European Organization for Standardization (CEN) has prepared a series of standards for energy performance calculations for buildings and systems. This paper presents related standards for heating systems. The relevant CEN-standards are presented and a sample calculation of energy performance is made for a small single family house, an office building and an industrial building in three different geographical locations: Stockholm, Brussels, and Venice.The additional heat losses from heating systems can be 10-20% of the building energy demand. The additional loss depends on the type of heat emitter, type of control, pump and boiler.     

The Carbon Cost of Work—Impacts of Office Building and Commuting Energy in Sydney Workplaces

We investigate greenhouse emissions of office workers in Sydney, drawing on census data, national building energy benchmarks as well as journey-to-work and energy data from two study buildings. Comparing work locations in the central business district (CBD) and Macquarie Park Corridor with metro-wide averages, we find that building emissions dominate over commuting emissions across the city, but commuting is increasingly important as building energy efficiency increases. Furthermore, our results indicate that efforts to improve a building's energy efficiency at Macquarie Park are largely negated by high reliance on car travel despite the introduction of the Epping–Chatswood train line. We conclude that improving building energy efficiency, office space utilisation and network connectivity (currently evident only in the CBD) delivers the best opportunity to reducing the carbon cost of workplaces.     

Impact of passive climate adaptation measures and building orientation on the energy demand of a detached lightweight semi-portable building

The building energy demand for heating and cooling is changing due to climate change. The adoption of climate change adaptation measures at the building scale aims at limiting heating and cooling demands. In previous studies on adaptation measures little attention has been paid to lightweight semi-portable buildings, which are increasingly used to temporarily house the growing number of small households (1–2 persons) in peripheral and derelict areas. In this paper the impact of passive climate adaptation measures and building orientation on heating and cooling demands is assessed for a detached, lightweight, semi-portable residential building by means of building energy simulations (BES), considering two climate scenarios for the Netherlands: current climate and a future climate (2050). The results show that the most efficient adaptation measure consists in a combination of exterior solar shading and an increase of thermal resistance of the building envelope, which reduces the annual heating and cooling demand–averaged over eight building orientations – by 11% for the current climate and 15% for the future climate. The impact of building orientation varies according to the climate scenario. Compared to the average over the eight orientations considered, the annual cooling demand for a single orientation varies between about ?31% and +22% and between about ?24% and +18% for the current and future climate, respectively. For the case without adaptation measures, optimizing the building orientation leads to annual total energy savings of about 4% for the current and 3% for the future climate.     

Energy consumption and potential energy savings in old school buildings

Energy and indoor environmental audits of energy consumption and indoor air quality were taken in 24 school buildings in Slovenia. The audits show that these buildings are high energy consumers and have poor indoor air quality, as expressed by 60% of the surveyed pupils. This article deals with energy consumption in the analysed schools. The nominal heating power of boilers, and heat exchangers, which are used in district heating, show a 57% overcapacity. The heat losses of the school buildings are 89% higher than the recommended values. According to our analysis of the possible measures to improve the situation in the school buildings, it will not be possible to ensure rational energy use and good indoor air quality with low investment costs. Should we change from hot-water heating systems and natural ventilation to energy efficient blown air systems with which one device provides the comfort of both heating and air conditioning?     

基于DeST-h软件的严寒、寒冷地区既有居住建筑绿色改造能耗分析

城镇既有居住建筑绿色改造是实现我国能耗总量控制、单位GDP二氧化碳排放量削减、绿色建筑建设的重要途径。通过选取严寒、寒冷地区气候子区典型城镇,并根据典型城镇历年人口、人均住宅面积以及相关设计规范等建立各气候子区典型城镇居住建筑模型;同时,采用建筑能耗模拟软件DeST-h模拟分析了严寒、寒冷地区历年既有居住建筑节能改造后的能耗情况,从而得到既有居住建筑绿色改造对严寒、寒冷地区的居住建筑能耗的影响,对同类既有居住建筑绿色改造具有一定的参考价值。