A user-centric space heating energy management framework for multi-family residential facilities based on occupant pattern prediction modeling

Space heating is the highest energy consumer in the operation of residential facilities in cold regions. Energy saving measures for efficient space heating operation are thus of paramount importance in efforts to reduce energy consumption in buildings. For effective functioning of space heating systems, efficient facility management coupled with relevant occupant behaviour information is necessary. However, current practice in space heating control is event-driven rather than user-centric, and in most cases relevant occupant information is not incorporated into space heating energy management strategies. This causes system inefficiency during the occupancy phase. For multi-family residential facilities, integrating occupant information within space heating energy management strategies poses several challenges; unlike with commercial facilities, in multi-family facilities occupant behavior does not follow any fixed activity-schedule pattern. In this study, a framework is developed for extracting relevant information about the uncertainties pertaining to occupant patterns (i.e., demand load) in multi-family residential facilities by identifying the factors affecting space heating energy consumption. This is achieved using sensor-based data monitoring during the occupancy phase. Based on the analysis of the monitoring data, a structure is defined for developing an occupant pattern prediction model that can be integrated with energy management strategies to reduce energy usage in multi-family residential facilities. To demonstrate the developed framework, a multi-family residential building in Fort McMurray, Canada, is chosen as a case study. This paper shows that integrating the developed occupant pattern prediction model within space heating energy management strategies can assist facility managers to achieve space heating energy savings in multi-family residential facilities.     

Transport,Housing and Urban Form: The Life Cycle Energy Consumption and Emissions of City Centre Apartments Compared with Suburban Dwellings

Buildings in cities and the activities carried out therein use a significant proportion of a nation's energy consumption and produce substantial quantities of greenhouse gases in the process. Residential buildings are a large contributor, partially as a result of the transport and housing activities of households. In this study, life cycle analysis is used to calculate the total transport and housing energy and emissions from a sample of 41 households in apartment buildings in the city centre of Adelaide, Australia and compare them with suburban households. The purpose of this is to determine whether the urban density option of higher rise dwellings offers a lower environmental impact than conventional housing. The analysis includes delivered energy and greenhouse gas emissions generated by motorised travel and activities within the dwellings, and the energy and emissions embodied in household motor vehicles and the apartment buildings. The total delivered energy consumption of apartment households was found to be lower than suburban households due mainly to higher car usage, particularly in the outer suburbs. However, the analysis of total greenhouse gas emissions provided a somewhat different comparison especially when they were considered on a per capita basis. The total per capita emissions for apartment households varied considerably but, on average, exceeded those of both the inner and outer suburban households. This resulted from lower occupancy rates and higher emissions arising from higher dwelling operational and embodied energy consumption. Overall, it cannot be assumed that centralised, higher density living will deliver per capita emission reductions for residents, once the combined per capita life cycle emissions from housing and transport have been accounted for. A more vigorous educational, promotional and regulatory approach is required to achieve greater operational and embodied energy efficiency in apartment buildings to fully realise the emissions-reducing potential of such buildings in centralised locations.

     

Case studies of energy consumption in residential buildings in Russia's middle belt area

This paper describes the analytical results of heating energy consumption monitoring and the determination of heat protection levels for both single-family and multi-family buildings in Russia. Experiments have been jointly conducted by Russian and American researchers from the Research Institute for Building Physics, Gosstroy of Russia, and the Natural Resources Defense Council. The paper describes qualimetric methods which provide a quantitative estimation of thermal and energy performance by using instrumental facilities and non-destructive methods.

The first Section gives a brief methodological summary for determining on-site building energy and thermal performance. The second part reviews the field results of energy monitoring to determine techniques that may result in the highest energy conservation effect for standard single-family houses in Russia. The third Section presents a comparative energy analysis of the use of highly insulating windows in a multi-family apartment building in field conditions. The experiments conducted prove that it is possible to ensure a 20–25% reduction in energy consumption for residential buildings under actual conditions existing in Russia. Finally, a methodology for assessing whole-building energy consumption for multi-family buildings is described.     

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.     

Behavioural Patterns and User Profiles related to energy consumption for heating

The difference between the actual and predicted energy consumption for heating in housing is thought to be partly attributable to the use of HVAC systems. More reliable data on energy consumption could help in determining the actual energy performance of dwellings and in the search for the most adequate design for housing and home amenities. Further reductions on energy consumption might also be achieved if energy-saving policy programmes were geared to different household groups. The aim of this paper is to statistically determine Behavioural Patterns associated with the energy spent on heating and to identify household and building characteristics that could contribute to the development of energy-User Profiles. This study had two outcomes: it identified Behavioural Patterns to be used in energy calculations and it discerned User Profiles with different behaviours. Five underlying groups of behavioural variables were found, which were used to define the Behavioural Patterns and User Profiles. The groups showed statistically significant differences in the scores for most of the behavioural factors. This study established clear relationships between occupant behaviour and household characteristics. However, it seems difficult to establish relationships between energy consumption and Behavioural Patterns and household groups.     

Theoretical and experimental thermal performance assessment of an innovative external wall insulation system for social housing retrofit

The UK building stock,being amongst the oldest in the developed world,is also one of the least energy efficient and accounts for approximately 45% of UK carbon emission. Energy use from housing alone was responsible for 13% of total UK carbon dioxide and greenhouse gas emissions in 2015. Therefore,achieving the national target of an 80% reduction in carbon emissions by 2050 against 1990 baseline conditions is highly dependent on the reduction of energy consumption in dw ellings. The complexity of the problem of retrofitting energy saving measures in the extensive and diverse aging housing stock is further compounded due to the number of "hard to treat " properties that comprise over 40% of homes in the UK. In this article,the authors present an evaluation of the theoretical and experimental performances of a novel prototype external wall insulation system,developed to improve energy efficiency in "hard to treat"housing. The system was designed to be primarily used to retrofit social housing,w hich comprises up to 18% of the current UK housing stock.A thorough testing regime was undertaken to test the suitability and effectiveness of the new product in the most common social housing construction typologies. This included: an investigation of the theoretical thermal performance of the prototype product through steady state modelling,a laboratory based prototype test,an analysis of empirical data collected from a cross section of social housing properties in Nottinghamshire,UK used to inform whole house dynamic modelling,and the development of dynamic simulations to assess the energy and carbon reduction impacts of the new product. The theoretical modelling suggested that the integration of the system resulted in thermal performance improvements for all construction types with space heating demand reduced by up to 42%. The results of the whole house dynamic modelling assessment also suggested that the addition of the system resulted in a reduction of heating energy demand of up to 49%. The prototyping testing show n that the system is easy to install requirement minimum building skills.The findings suggest that the new product not only meets the performance of existing external wall insulation systems,but also provides unique selling points with respect to easy installation and non-reliance on weather conditions. The project finished with a pilot study when one house was retrofitted using the novel product.     

Addressing climate change in comfort standards

According to the Buildings Energy Data Book published by the U.S. Department of Energy, in 2006 the building sector consumed 38.9% of the total primary energy used in the United States. Of this energy, 34.8% is used by buildings for space heating, ventilation, and air conditioning. This energy often involves the combustion of fossil fuels, contributing to carbon dioxide emissions and climate change. Even if greenhouse gas concentrations are stabilized in the atmosphere, extreme climate events and sea level rise will continue for several centuries due to inertia of the atmosphere. Therefore, adaptation will be a necessary compliment to carbon dioxide mitigation efforts. This paper argues that both mitigation of greenhouse gases and adaptation to climate change should be added to our building codes and standards. Since space heating, ventilation, and air-conditioning utilize a large amount of energy in buildings, we should begin by redefining our thermal comfort standards and add strategies that mitigate carbon dioxide emissions and adapt to predicted climate variability.     

Development of a framework of key performance indicators to identify reductions in energy consumption in a medical devices production facility

The consumption of energy in manufacturing operations is growing in significance and approaches to reduce the resulting environmental impacts are necessary. Whilst companies have focused on reducing energy at a facilities level, research indicates that specific production processes generate significant environmental impact through energy consumption and greenhouse gas emissions. Potential energy savings have been identified in production processes; however the necessary tools are missing. The development of energy performance indicators have been described in theory but there is little evidence of their successful application in practice. This research proposes the application of a normalised co-efficient to view production and energy data and the development of a rolling energy performance co-efficient to provide alerts to ‘out-of-control’ production operations. Implementation of the approach in a large medical devices manufacturing facility has identified significant savings. Key consideration in the development of energy key performance indicators for production operations are described.     

Environmental implications of water efficient microcomponents in residential buildings

The Code for Sustainable Homes (CSH) in England sets out various water efficiency targets/levels, which form part of environmental performance criteria against which the sustainability of a building is measured. The code is performance based and requires reduction in per capita water consumption in households. The water efficiency related targets can be met using a range of water efficient microcomponents (WC, showers, kitchen taps, basin taps, dishwashers, washing machines, and baths). However, while the CSH aims at reducing the adverse environmental implications associated with the dwellings by promoting reduction in water consumption, little is known about the energy consumption and the environmental impacts (e. g. carbon emissions) resulting from water efficient end uses. This paper describes a methodology to evaluate the energy consumption and carbon emissions associated with the CSH's water efficiency levels. Key findings are that some 96% and 87% of energy use and carbon emissions, respectively associated with urban water provision are attributable to in-house consumption (principally related to hot water), and that achieving a defined water efficiency target does not automatically save energy or reduce carbon emissions.     

The effect of occupancy and building characteristics on energy use for space and water heating in Dutch residential stock

As a consequence of the improved quality of thermal properties of buildings due to energy regulations, overall energy use associated with building characteristics is decreasing, making the role of the occupant more important. Studies have shown that occupant behaviour might play a prominent role in the variation in energy consumption in different households but the extent of such influence is unknown. The impact of the building's thermal characteristics on space heating demand has been well studied. There is however, little work done that incorporates the impact of consumer behaviour. This study aims to gain greater insight into the effect of occupant behaviour on energy consumption for space heating by determining its effect on the variation of energy consumption in dwellings while controlling for building characteristics. The KWR database from the Ministry of Housing in the Netherlands was used. This study showed that occupant characteristics and behaviour significantly affect energy use (4.2%), but building characteristics still determine a large part of the energy use in a dwelling (42%). Further analysis showed that some occupant behaviour is determined by the type of dwelling or HVAC systems and, therefore, the effect of occupant characteristics might be larger than expected, since these determine the type of dwelling.     

成都地区太阳能与燃气锅炉耦合系统的节能研究

本研究以成都地区某住宅热水系统为例,应用了一种太阳能辅助燃气锅炉供热水的系统。通过TRNSYS软件模拟分析了该系统的燃气消耗量、水泵能耗以及相应的温室气体排放量。结果表明,在保证相同温度热水输出的情况下,应用太阳能集热器辅助加热燃气锅炉可以明显地减少燃气消耗量;在此基础上,可以相应地减少CO2等温室气体的排放,得出了该耦合系统具有明显节能效益和较好的减排效益。     

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.     

基于全生命周期分析的北方农村住宅被动式集热墙体的环境影响分析

该文采用全生命周期的分析方法,比较在采用相同保温措施的情况下,与普通保温墙体相比,三种形式的被动集热墙在全寿命周期的范围内的采暖能源消耗、温室气体及固体废弃物排放情况.通过比较分析可以看出,直接受益式和附加阳光间式集热墙体在能源消耗、温室气体和固体废弃物的排放量上均小于对比房,在环境影响上具有明显的优越性;集热蓄热墙的...     

Performance gaps in energy consumption: household groups and building characteristics

ABSTRACT

The difference between actual and calculated energy is called the ‘energy-performance gap’. Possible explanations for this gap are construction mistakes, improper adjusting of equipment, excessive simplification in simulation models and occupant behaviour. Many researchers and governmental institutions think the occupant is the main cause of this gap. However, only limited evidence exists for this. Therefore, an analysis is presented of actual and theoretical energy consumption based on specific household types and building characteristics. Using a large dataset (1.4 million social housing households), the average actual and theoretical energy consumptions (gas and electricity) of different household types and characteristics (income level, type of income, number of occupants and their age) were compared for each energy label. Additionally, the 10% highest and lowest energy-consuming groups were analysed. The use of combinations of occupant characteristics instead of individual occupant characteristics provides new insights into the influence of the occupant on energy demand. For example, in contrast to previous studies, low-income households consume more gas per m² (space heating and hot water) than households with a high income for all types of housing. Furthermore, the performance gap is caused not only by the occupant but also by the assumed building characteristics.     

Comparison of environmental impacts of two residential heating systems

This paper presents a comparison of environmental impacts of two residential heating systems, a hot water heating (HWH) system with mechanical ventilation and a forced air heating (FAH) system. These two systems are designed for a house recently built near Montreal, Canada. The comparison is made with respect to the life-cycle energy use, the life-cycle greenhouse gas (GHG) emissions, the expanded cumulative exergy consumption (ECExC), the energy and exergy efficiencies, and the life-cycle cost. The results indicate that the heating systems cause marginal impacts compared with the entire house in the pre-operating phase. In the operating phase, on the other hand, they cause significant environmental impacts. The HWH systems with a heat recovery ventilator (HRV) using either electricity or natural gas have the lowest life-cycle energy use and lowest ECExC. The HWH and FAH systems using electricity as energy source have the lowest GHG emissions. Finally, the FAH systems have, on the average, a lower life-cycle cost than the HWH systems.     

Towards a universal energy efficiency index for buildings

The growing worldwide demand for energy is basically satisfied through natural resources such as oil or natural gas generally acknowledged as being responsible for climate change through greenhouse gas emissions. The building sector accumulates approximately a third of the final energy consumption. Consequently, the improvement of the energy efficiency in buildings has become an essential instrument in the energy policies to ensure the energy supply in the mid to long term, and to meet the targets stated in the Kyoto Protocol. During the last decade and being sensitive to this fact, many national governments and international organizations have developed new regulations to achieve those targets. One of these regulations is the European Energy Performance of Buildings Directive but, to date this certification does not follow a standard procedure which is universally accepted.This paper aims to contribute to this standardization, proposing an energy efficiency index for buildings that relates the energy consumption within a building to reference consumption. The proposed energy index can be obtained in a simple manner by combination standard measurements of energy consumption, simulation and public databases. Furthermore, the index is upgradable whenever new data are available.     

Computational intelligence techniques for HVAC systems: A review

Buildings are responsible for 40% of global energy use and contribute towards 30% of the total CO2 emissions. The drive to reduce energy use and associated greenhouse gas emissions from buildings has acted as a catalyst in the development of advanced computational methods for energy efficient design, management and control of buildings and systems. Heating, ventilation and air-conditioning (HVAC) systems are the major source of energy consumption in buildings and ideal candidates for substantial reductions in energy demand. Significant advances have been made in the past decades on the application of computational intelligence (CI) techniques for HVAC design, control, management, optimization, and fault detection and diagnosis. This article presents a comprehensive and critical review on the theory and applications of CI techniques for prediction, optimization, control and diagnosis of HVAC systems. The analysis of trends reveals that the minimisation of energy consumption was the key optimization objective in the reviewed research, closely followed by the optimization of thermal comfort, indoor air quality and occupant preferences. Hardcoded Matlab program was the most widely used simulation tool, followed by TRNSYS, EnergyPlus, DOE-2, HVACSim+ and ESP-r. Metaheuristic algorithms were the preferred CI method for solving HVAC related problems and in particular genetic algorithms were applied in most of the studies. Despite the low number of studies focussing on multi-agent systems (MAS), as compared to the other CI techniques, interest in the technique is increasing due to their ability of dividing and conquering an HVAC optimization problem with enhanced overall performance. The paper also identifies prospective future advancements and research directions.     

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.     

Understanding embodied greenhouse gas emissions in the water and sewerage sectors

Embodied (or embedded) greenhouse gas emissions are commonly overlooked in corporate carbon accounting, although they can represent a large proportion of overall emissions. In this paper, we utilise embodied emission data submitted to Ofwat, the economic regulator of water and sewerage companies in England and Wales, as part of their review of price limits. This is the first time that water and sewerage companies have presented embodied emissions associated with their capital programmes. In total, embodied emissions add an extra 50% on top of companies' operational greenhouse gas emissions. We consider the drivers for embodied emissions and show that capital maintenance programmes are the largest source. We highlight the relationship between capital expenditure and embodied emissions, and discuss why there are significant differences in embodied emission intensities between companies. Many of the differences arise from the way the common methodology for estimating embodied emissions is applied.     

房屋住宅中降低建筑能耗的节能设计及应用

当今,低碳技术发展迅速,新技术、新工艺、新材料层出不穷。将低碳技术成功地运用到房屋住宅中,可以节约能源、控制温室气体排放,改善当地的建筑环境质量,对应对全球气候变化有着重要的意义。通过低碳技术在房屋住宅中的应用,积极创新思路和管理模式,努力降低建筑建造和使用过程中的能源消耗,引导房屋住宅和建筑节能的健康发展。