Environmental impact of building-related and user-related energy consumption in dwellings

Energy consumption in dwellings contributes significantly to their total negative environmental impact. This paper quantitatively assesses the environmental impact of building-related and user-related gas and electricity consumption in a Dutch apartment dwelling using life cycle assessment (LCA) methodology. Several scenarios for gas and electricity consumption are compared to assess what effect changes in building characteristics and user behaviour have on the environmental impacts of energy consumption. This study shows that gas consumption significantly contributes to four environmental impact categories, which can be most effectively countered by reducing the heat demand of the dwelling. A 23% reduction in gas consumption leads to up to 13% less overall environmental impacts. Particularly in buildings with low heat demand, electricity consumption dominates all environmental impact categories. These can most effectively be reduced by changing the electricity demand of the user: 47% less electricity consumption leads to a 9–45% reduction in the total environmental impact. However, since electricity consumption continues to rise, the environmental effects of electricity use may be better reduced by changing the environmental impact of the electricity supply. Theoretically, when electricity consumption remains the same, over 90% less environmental impact could be reached by using 100% wind power to generate electricity.     

住宅建筑地下室顶板对采暖能耗的影响研究

本文在分析我国居住建筑能耗特点及现状的基础上,阐述了降低居住采暖能耗的必要性;鉴于我国建筑节能技术的应用现状,针对济南市某住宅楼,分析了四种地下室顶板对采暖能耗的影响,求出了满足节能50%目标地下室顶板应具备的最小热阻及构造做法.     

The impact of consumer behavior on residential energy demand for space heating

Besides technical parameters, consumer behavior is the most important issue with respect to energy consumption in households. In this paper, the results of a cross-section analysis of Austrian households are presented. The impact of the following parameters on residential energy demand for space heating have been investigated: (i) thermal quality of buildings; (ii) consumer behavior; (iii) heating degree days; (iv) building type (singleor multi-family dwellings). The result of this investigation provides evidence of a rebound-effect of about 15 to 30% due to building retrofit. This leads to the conclusion that energy savings achieved in practice (and straightforward the reduction in CO₂ emissions) due to energy conservation measures will be lower than those calculated in engineering conservation studies. Straightforward, the most important conclusions for energy policy makers are: (i) Standards, building codes, respectively, are important tools to increase the thermal quality of new buildings; and (ii) Due to prevailing low energy prices, a triggering tool has to be implemented which may be rebates or loans.     

Climatic exposure and fuel consumption in high rise dwellings

The hypothesis tested is whether fuel consumption returns for individual dwellings in a high rise building reflect the varying degrees of climatic loading to which such buildings are subjected. A multi-storey block has been chosen in order to study the effects of change of climate with height.The method of investigation and analysis is based simply on the assumption that changes in the climatic envelope around buildings are experienced within the buildings by the occupants who, in order to maintain levels of thermal comfort, adjust the internal environment by regulating the heat load. Fuel consumption returns are the means by which changes in the heat load and hence in the external environment are demonstrable.Statistical and wind tunnel analyses are compared.     

Quantifying the extent of space shortages: English dwellings

Lack of internal space is a problem in UK homes, and is often linked to a lack of space standards for housing in the UK. Although previous studies have examined new-build housing, this paper uses a new method to study 16 000 dwellings in the English Housing Survey (EHS) 2010 to examine existing housing and compare them with a modern space standard in an attempt to quantify the extent and magnitude of the problem. Dwellings in the survey were compared against a slightly modified version of the London Housing Design Guide 2010 internal space standard. It was found that between 21% and 55% of dwellings failed to meet the standard; and that flats and small terraced houses were most commonly below the standard. Dwellings were also frequently found to be under-occupied in comparison with the number of bedrooms. This research hypothesized that this was a result of the lack of space. To illustrate the use of this new analysis method, a recent change to the Housing Benefit system (colloquially known as the ‘Bedroom Tax’) has been considered. Households receiving Housing Benefit were more likely to be undersized, suggesting that the policy to withdraw housing benefits from these households may be misguided.     

Uptake of energy efficiency interventions in English dwellings

Little detailed evidence has previously been available regarding the uptake rate or prevalence of energy efficiency interventions among specific household groups. This study uses the Home Energy Efficiency Database (HEED) to investigate both the combination of measures that have been installed, and in which dwellings, according to key neighbourhood socio-demographic variables, including income and tenure. Analysis of 2000–07 data indicates that approximately 40% (9.3 million) dwellings in England had approximately 23.7 million efficiency measures installed, with an average of 2.5 measures per dwelling. Building fabric-related measures were the most frequent (e.g. cavity wall insulation, loft insulation and glazing) with an average of 2.1 million installed each year. Dwellings with the highest number of fabric interventions (the top 20%) were more likely to be found in areas with low income, with more owner-occupied dwellings, experiencing lower winter temperatures, having a lower proportion of flats, and having a slightly higher proportion of older adults and children. Energy efficiency installations have tended to occur among specific types of households or parts of the building stock. These findings have implications for the design of future government programmes for targeting energy efficiency measures to specific household groups or dwelling types.     

The impact of building-integrated photovoltaics on the energy demand of multi-family dwellings in Brazil

Brazil faces a continuous increase of energy demand and a decrease of available resources to expand the generation system. Residential buildings are responsible for 23% of the national electricity demand. Thus, it is necessary to search for new energy sources to both diversify and complement the energy mix. Building-integrated photovoltaic (BIPV) is building momentum worldwide and can be an interesting alternative for Brazil due its solar radiation characteristics. This work analyses the potential of seven BIPV technologies implemented in a residential prototype simulated in three different cities in Brazil (Natal, Brasília and Florianópolis). Simulations were performed using the software tool EnergyPlus to integrate PV power supply with building energy demand (domestic equipment and HVAC systems). The building model is a typical low-cost residential building for middle-class families, as massively constructed all over the country. Architectural input and heat gain schedules are defined from statistical data (Instituto Brasileiro de Geografia e Estatística—Brazilian Institute for Geography and Statistics (IBGE) and Sistema de Informações de Posses de Eletrodomésticos e Hábitos de Consumo—Consumer Habits and Appliance Ownership Information System (SIMPHA)). BIPV is considered in all opaque surfaces of the envelope. Results present an interesting potential for decentralized PV power supply even for vertical surfaces at low-latitude sites. In each façade, BIPV power supply can be directly linked to local climatic conditions. In general, for 30% of the year photovoltaic systems generate more energy than building demand, i.e., during this period it could be supplying the energy excess to the public electricity grid. Contrary to the common belief that vertical integration of PV is only suitable for high latitude countries, we show that there is a considerable amount of energy to be harvested from vertical façades at the sites investigated.     

The impact of energy externalities on the cost effectiveness of energy efficiency measures applied to dwellings

European Union and UK energy policy recognise the potential contribution the domestic housing sector can make in reducing energy consumption. In the UK, improvements to existing dwellings are likely to play a critical role in realising such potential. The need to consider both the value and uncertainty of external environmental and social costs in developing effective policy is also made explicit.This analysis investigates the impact of such values and uncertainties on the relative performance of a range of insulation measures applied retrospectively to an existing residential dwelling.Results from a case study suggest that large variations in capital cost, energy saving potential and the value of externalities have a significant impact on the relative cost effectiveness of these measures. However, in general, current investment decision-making based on normal market energy prices and today's climate is likely to deliver solutions that remain effective under significant levels of uncertainty.     

供热采暖系统能耗分析及节能措施探讨

通过对我国地方供热采暖系统的能耗原因分析,提出在围护结构、热源、管网、室内采暖系统及其他途径等方面的节能措施,从而使节能技术步入良性循环轨道,促进建筑节能的发展。     

Further investigations relating to climatic exposure and fuel consumption in high rise dwellings

Primary heating fuel consumption by banks of dwellings in a high-rise block has been analysed previously by the author. The studies confirmed that consumption differences between dwellings were the result of dissimilarities in the climatic loading at any one time. More particularly these consumption differences were seen to be the direct result of heat loss caused by differential airflow on and around the building.

This paper extends the earlier studies by analysing secondary heating consumption returns in a similar manner and making comparisons with previous results.     

The impact of climate change uncertainties on the performance of energy efficiency measures applied to dwellings

European Union and UK energy policy recognise the potential contribution the domestic sector can make in reducing energy consumption. In the UK, improvements to existing dwellings are likely to play a critical role in realising such potential.There is growing evidence that the global climate is changing. In the UK, projected climate changes could have a considerable impact on the thermal performance of the built environment and on measures implemented to improve such performance.Building simulations designed to investigate the potential impact of climate change uncertainties on the performance of insulation measures, applied retrospectively to an existing residential dwelling, suggest their effect could be considerable. Thermally, double glazing is the best option because although it is more sensitive than the others to climate change, it still delivers the highest savings in heating energy demand for the lowest induced cooling load. Loft insulation is the worst option in thermal terms.     

Occupant behaviour in energy efficient dwellings: evidence of a rebound effect

The energy required for space heating has been significantly reduced in recent decades by making use of insulation and more efficient heating and ventilation systems. Even so, wide variations in energy consumption are still observed between similar dwellings and between actual and predicted levels. It is thought that these variations stem from differences in occupant behaviour, the structural quality of the building, and a rebound effect. This paper statistically examines differences in occupant behaviour in relation to the building characteristics of the housing stock in the Netherlands and explores the possible existence of a rebound effect on the consumption of energy for space heating. Rebound effect can be defined as the increase on energy consumption in services for which improvements in energy efficiency reduce the costs. We found that although energy consumption is lower in energy efficient dwellings, analysis of the behaviour variables indicates their occupants tend to prefer higher indoor temperatures and to ventilate less. This finding might be related to a rebound effect on occupant behaviour. However, the improvement of thermal properties and systems efficiency still lead to a reduction on energy consumption for heating.     

发展多元化采暖技术 降低采暖能耗

大家好!林润泉同志曾经向我汇报《低温辐射电热膜》标准的编制工作,我对这项工作非常支持。我们国家经济发展模式要转型,要提高到一个新的历史阶段。在这个历史阶段里,用科学发展观来指导我们的一切工作,要发展科学技术,进行科技革命。新的科技革命将对经济     

缓冲空间对拉萨市居住建筑冬季采暖能耗的影响

冬季现场调研与热环境测试表明,拉萨市现有居住建筑的缓冲空间能明显改善室内热环境。但当地非采暖房间冬季热环境仍较差,居住建筑采暖需求明显。当地采暖能耗与环境负荷增长趋势明显。以拉萨市常见的单元式住宅为基础建立了热工计算模型,模拟分析了南北向缓冲空间进深设计对冬季采暖能耗的影响规律。结果表明:南北向缓冲空间均能有效降低模型的采暖能耗,其中,随着南向缓冲进深增大,模型采暖能耗呈递增趋势;随北向缓冲空间进深增大,模型采暖能耗呈先降后增趋势,北向缓冲空间模型之间能耗差很小。缓冲空间优化设计模型与基础模型的能耗对比分析显示,合理设置的南北向缓冲空间能够大幅降低采暖能耗。     

发热电缆地面辐射供暖系统在节能住宅中的能耗分析

本文对发热电缆地面辐射供暖系统的能耗进行理论和实际应用工程相结合的分析,并与集中供热收费标准进行了对比,提出了该系统节能并应推广的观点。     

窗墙比对居住建筑的冷热耗量指标及节能率的影响

以高层公寓式居住建筑为对象,利用特征温度法研究了对建筑采取相同改进措施时窗墙面积比对建筑冷热耗量和能耗相对变化率的影响,并分析了当建筑体形系数不同时,窗墙面积比对全年空调与供暖冷热耗量指标以及采取相同节能措施建筑的全年空调与供暖节能量及节能率的影响。     

建筑气密性对供暖能耗的影响

以哈尔滨、北京、上海三个地区为例,分析了提高建筑气密性对供暖能耗的影响.研究发现,在严寒和寒冷地区,提高建筑气密性能有效减少渗风带来的供暖能耗,但当建筑气密性过高时,需要采用机械通风保证室内通风设计要求,风机能耗随着通风量增大而增大;在夏热冬冷地区,提高建筑气密性同时需要采用机械通风,增加了风机能耗,总能耗增加.采用机械通风的同时,对排风进行热回收可以减少供暖能耗,在严寒和寒冷地区节能效果明显.     

Movers and stayers: The resident's contribution to variation across houses in energy consumption for space heating

A general method is proposed that identifies the contribution of resident-dependent effects to the observed variability of energy consumption in similar houses. The method presumes that in addition to records of energy consumption over time, one has access to information about the date of change of occupants. For Twin Rivers data, the role of resident-dependent effects is seen to dominate the role of effects that depend on structural variations over which the resident has no effective control.     

The potential of energy flexibility of space heating and cooling in Portugal

This study assesses the potential of energy flexibility of space heating and cooling for a typical household under different geographical conditions in Portugal. The proposed approach modifies the demand through the optimization of the thermostat settings using a genetic algorithm to reduce either operational costs or interaction with the grid. The results show that the used energy flexibility indicator expresses the available potential and that flexibility depends on several factors, namely: i) thermal inertia of the archetypical household; ii) the time of use electricity tariffs; iii) users’ comfort boundaries; and iv) the geographical location of the houses.     

Simulation of the impact of financial incentives on solar energy utilization for space conditioning and water heating: 1985

Financial incentives designed to accelerate the use of solar energy for heating, cooling, and water heating of buildings have been proposed by both state and federal legislative bodies in the U.S.A. Among the most frequently mentioned incentives are sales and property tax exemptions, tax deductions and credits, rapid amortization provisions, and interest rate subsidies. At the present time there is little available information regarding the ability of such incentives to advance the rate of solar energy utilization. This paper describes the derivation and use of a computer simulation model designed to estimate solar energy use for space conditioning and water heating for given economic, climatic, and technological conditions. When applied to data from the Denver, Colorado metropolitan area, the simulation model predicts that sales tax exemptions would have little impact over the next decade, interest rate subsidies could more than double solar energy use, and the other proposed incentives would have an intermediate impact.