Check and evaluation system on heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of china based on multi-index comprehensive evaluation method

Heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China is organized and implemented in a large scale by local government in 15 provinces of North China with the unified guidance and control of central government. Firstly, this paper introduced the target of energy-saving reformation of existing residential buildings in North China and the importance of check and evaluation on this target, then pointed out the necessity of building up an evaluation system for energy-saving retrofit. According to the analytical hierarchy process (AHP), three-grade evaluation system was built up for heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China. Also, based on multi-index comprehensive evaluation method combined with life cycle assessment (LCA) theory, post-evaluation thought and successful degree evaluation method, a mathematical model was established. Finally, a set of scientific method for evaluating heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China systematically, scientifically, comprehensively and objectively was created.     

Achievements and suggestions of heat metering and energy efficiency retrofit for existing residential buildings in northern heating regions of China

In order to promote energy efficiency and emission reduction, the importance of improving building energy efficiency received sufficient attention from Chinese Government. The heat metering and energy efficiency retrofit for existing residential buildings of 0.15 billion m² in northern heating regions of China was initiated in 2007 and completed successfully at the end of 2010. This article introduced the background and outline of the retrofit project during the period of 11th five-year plan. Numerous achievements that received by retrofit such as environmental protection effect, improvement of indoor environment, improvement of heating system, investment guidance effect, promotion of relevant industries and increasing chances of employment were concluded. Valuable experience that acquired from the retrofit project during the period of 11th five-year plan was also summarized in this article. By analyzing the main problems emerged in the past, pertinent suggestions were put forward to promote a larger scale and more efficient retrofit project in the period of 12th five-year plan.     

Pattern analysis and suggestion of energy efficiency retrofit for existing residential buildings in China's northern heating region

In China, Energy Efficiency Retrofit for Existing Residential Buildings (EERFERB) is faced with a fast development status. The Central Government decided to prompt the retrofit of 1.5×10⁸ m² existing residential buildings in China's northern heating region during the “11th Five-Years Plan”. But, at present, the relative incentive policies and measurements are very insufficient. Especially, on the aspect of the retrofit pattern about the organization, retrofit content, investing and financing mode, the policy and management and other factors, no existing successful one can be spreaded into the whole northern heating region. This research not only analyzed the foreign advanced methods, drew lessons from their retrofit in Germany and Poland, but contrasted and analyzed energy efficiency retrofit demonstrations from Harbin, Tianjin, Tangshan and Baotou in China to get our domestic successful patterns and experience. Finally, some recommended retrofit patterns are presented, which can be applied for the instruction and decision-making for the Chinese local governments.     

Target-oriented obstacle analysis by PESTEL modeling of energy efficiency retrofit for existing residential buildings in China's northern heating region

According to the “Comprehensive Work Program of Energy Efficiency and Emission Reduction” of the Chinese government, during the period of the “11th Five-Year Plan”, 1.5×10⁸ m² of existing residential buildings in China's northern heating region are to be retrofitted for energy efficiency. However, at present, this “Energy Efficiency Retrofit for Existing Residential Buildings” (EERFERB) faces many obstacles. Under the current working and market system, both the central and local governments and the energy supply companies can not push on this work smoothly. Using both the results of the annual national special inspection of building energy efficiency and some case analyses, this paper examines the necessity for energy efficiency retrofit, along with the relationships among the various Political, Economic, Social, Technological, Environmental and Legal (PESTEL) factors affecting it. Furthermore, organizational, financial and technical support systems are explored to promote the development of retrofit. Finally, some primary principles to be followed toward the implementation of EERFERB are suggested.     

Individual metering of energy in existing buildings: potential and critical aspects

Individual metering of energy in flats is a real opportunity to save energy and money for the occupiers of collective-ownership buildings with centralised heating systems. The individual management of energy, through such devices, make users more responsible and also stimulates them to implement energy retrofit interventions in their flats. The use of individual metering systems in existing apartments, however, could have some critical aspects. The purpose of this paper is to analyse the application of individual energy systems in existing collective-ownership residential buildings, highlighting the critical aspects and providing practical solutions to overcome them. A study has been made of an individual metering application in an existing residential block of flats located in Milan (Italy) with poor thermal insulation between the various dwellings themselves and for the outside walls of the building. Although a net reduction of 50.4 % in the global costs for winter heating, obtained exclusively through plant-modification works, represents an optimum goal for energy savings, the study highlight some critical aspects. The savings for different apartments differ greatly and depend upon the criteria chosen for burden sharing. This study shows that the phenomenon of “heat theft” can prove to be important and provides the possibility of reducing to zero the quota of expenses from consumption whilst still benefiting from comfortable temperatures. Once the problems have been identified, the paper then proposes solutions to overcome them through a revision of the criteria for the allocation of energy costs.     

Energy efficiency outlook in China’s urban buildings sector through 2030

This study uses bottom-up modeling framework in order to quantify potential energy savings and emission reduction impacts from the implementation of energy efficiency programs in the building sector in China. Policies considered include (1) accelerated building codes in residential and commercial buildings, (2) increased penetration of district heat metering and controls, (3) district heating efficiency improvement, (4) building energy efficiency labeling programs and (5) retrofits of existing commercial buildings.Among these programs, we found that the implementation of building codes provide by far the largest savings opportunity, leading to an overall 17% reduction in overall space heating and cooling demand relative to the baseline. Second are energy efficiency labels with 6%, followed by reductions of losses associated with district heating representing 4% reduction and finally, retrofits representing only about a 1% savings.     

Analysis of ground source heat pumps with horizontal ground heat exchangers for northern Japan

Computer simulation and analysis of a ground source heat pump system with horizontal ground heat exchangers operating in heating (max 5.5 kW) and cooling (max 3.3 kW) mode was carried out for a typical residential house, with 200 m² of living space, located in Sapporo (Japan). In spite of high electricity rate, the ground source heat pump system is more beneficial alternative for space heating than an oil furnace and an electric resistance system. Besides, the heat pump technology offers relatively low thermal degradation of the ground environment, lower cost of heating and cooling, higher operating efficiency than electric resistance heating or air-source heat pump and is environmentally clean, i.e. without greenhouse gas emission, if the electricity is generated from renewable energy resources, such as wind and solar. The use of the cooling mode can provide further benefits like a shorter investment payback and human thermal comfort in summer. As a result, application of horizontal loops for new and retrofit residential and commercial use in northern Japan is feasible particularly in farmland areas.     

既有居住建筑供热计量改造技术分析与能效评估

对枣庄市某小区供热计量改造项目进行了技术分析与能效评估,为其他节能改造项目提供参考,有助于推动既有居住建筑节能改造的推广。     

The analysis of energy consumption of a commercial building in Tianjin,China

According to statistics and field investigation, the energy consumption situation and reality of commercial building is described in this paper. As the first step of large-scale public building energy efficiency supervision system encouraged by central government of China, the energy consumption of several typical commercial buildings and public buildings was analyzed in detail. The main contents of investigation are as follows: basic information of building, operational record of energy consumption equipment, energy consumption of indoor equipments, energy-efficiency assessment of energy consumption systems and equipments, investigation of behavior energy saving, etc. On this basis further analysis and diagnosis including indoor thermal and humid environment, operation state of air-conditioning water system, operation state of air-conditioning duct system and operation management of air-conditioning system were implemented. The results show that the most energy consumption of buildings in this city is commercial buildings, which can reach to about 240 W/m² per year. Further analysis tells that air conditioning systems play the major role of building energy consumption, and building energy saving has great potential in this city. In this paper, the ways of diagnosis work for building energy consumption are also described and discussed. Reasonable test, diagnosis and analysis are meaningful for building energy efficiency retrofit and management.     

Energy and behavioral impacts of integrative retrofits for residential buildings: What is at stake for building energy policy reforms in northern China?

Based upon the results from extensive building monitoring and surveys on occupant’s behaviors in a representative nine-story apartment building in northern China, building energy simulations were performed to evaluate the impacts of integrative retrofits implemented. Integrative retrofits required by the newer building energy standard produced significant heating-energy savings (i.e., 53%) when compared with baseline buildings commonly built in early 1980s. Taking into account district-heating-system upgrades as part of integrative retrofit measures, a representative apartment building was 66% more efficient than the baseline building. Contrary to expectation, little behavioral change was found in response to the provisions of monetary incentive, billing-method reform, or metering of heating energy use in individual apartment units. Yet this paper identified sizable energy savings potential if occupants’ behavioral changes were to actually happen. This indicates that provisions of financial incentives or individual metering were insufficient for triggering substantial behavioral changes leading toward more energy savings in the current buildings. It is recommended that innovative energy policies, technology upgrades, and education would be needed to promote behavioral changes toward additional energy savings. Finally, measures and strategies to further enhance thermal integrity criteria (e.g., insulations of roof and balcony) are recommended in China’s future building energy policy reforms.     

Heat prices for public buildings in Tianjin

Energy-saving awareness of heat users and heating enterprises can be stimulated by implementing heat metering for public buildings and by establishing scientific and reasonable policies for heat prices in China. In this paper, a two-part heat price for public buildings in Tianjin is introduced, which divides the heat price into a basic part and a metering part. According to the statistical analysis of information collected from two pilot heating enterprises, the specific heat load for public buildings in Tianjin is calculated, and three candidate schemes of heat price are proposed. A simulation of heat cost is also conducted, and the benefits for both heat users and heating enterprises are balanced. Finally, the two-part heat price for public buildings in Tianjin is determined: the basic heat price is recommended to be 20 CNY/m², and the metering heat price is recommended to be 76.10 CNY/GJ. Such a price could be implemented in the initial stage of heat metering for public buildings in Tianjin.     

The thermal performance of window coverings in a whole house test facility with single-glazed sash windows

The residential sector is responsible for 29% of the total energy consumption of the UK, with 62% of this energy being used for space heating. Heat loss through the fabric of building elements is a crucial factor in the energy efficiency of homes, and a wide number of studies have looked at physical interventions to improve the energy efficiency of existing buildings, commonly called retrofit. This research considers the impact of window coverings on reducing heat loss from homes, a measure that is not commonly considered an energy efficiency intervention. Although the amount of glazing varies widely between homes, all windows are a significant factor contributing to heat loss. While physical changes such as double and triple glazing can improve the energy performance of buildings, the impact of curtains and blinds is not well characterised. Previous research into window coverings has been undertaken using laboratory tests, such as hotbox and small climatic chamber environments. This study presents the impact of window coverings on heat loss within a unique whole house test facility. This allows for a better replication of a real heating system and the effects that it has on localised heat transfer. This gives a more detailed picture of in situ performance, similar to that which may be found in the field.     

Evaluation on energy and thermal performance for residential envelopes in hot summer and cold winter zone of China

As a result of rapid economic growth in the last several decades, energy issue is becoming more and more important in today’s world because of a possible energy shortage in the future; the usage of residential electricity has increased rapidly in China and building energy efficiency is included as one of the 10 key programs targeting energy efficiency improvement in the 11th Five-Year Plan. In response to the growing concerns about energy conservation in residential buildings and its implications for the environment, systematic evaluation on energy and thermal Performance for residential envelops (EETP) is put forward to assess the energy efficiency of envelop designs and to calculate the energy consumption of cooling and heating systems. Hot summer and cold winter zone of China was selected for EETP analysis because of its rigorous climatic and huge energy consumption. The correlations between EETPs and electricity consumptions in cooling season, heating season, and the whole year were built in Shanghai, Changsha, Shaoguan and Chengdu, which represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. Illustrations indicate that the algorithm is simple and effective, energy and thermal performance of residential envelopes can be evaluated easily. The maximum allowable values of EETPs were determined when just meeting the compulsory indices of Standard JGJ134-2001, the corresponding allowable EETPs were also gained when achieving different energy-saving degrees on basis of it. EETP method can suggest possible ways to improve the energy efficiency for envelope designs of new building and retrofits of existing buildings and provide governments some useful information for the establishment of new policy on energy efficiency buildings. It has important meanings to carry out sustainable residential building designs with high thermal comfort and low energy consumption.     

Energy performance of building envelopes in different climate zones in China

Energy performance of office building envelope designs in the five major climate zones – severe cold, cold, hot summer and cold winter, mild, and hot summer and warm winter – in China was investigated. A major city within each climate zone was selected. These were Harbin, Beijing, Shanghai, Kunming and Hong Kong. Generic building envelopes were developed based on data gathered from building surveys, local energy codes and the ASHRAE Standard. The overall thermal transfer value (OTTV) method and the heating degree-days technique were adopted in the analysis. Cooling and heating requirements due to heat gain/loss through the building envelopes were determined based on the respective OTTV parameters and building load coefficients. Different shape coefficients were also considered. For a typical floor, chiller load due to heat gain through the building envelope varied from 1.0 kW h/m² in Kunming to 23.5 kW h/m² in Beijing, and the heating load ranged from 2.7 kW h/m² in Hong Kong to 124.3 kW h/m² in Harbin.     

Heating energy savings potential from retrofitting old apartments with an advanced double-skin façade system in cold climate

Apartments account for over 60% of total residential buildings and consume a significant portion of primary energy in South Korea. Various energy efficiency measures have been implemented for both new apartment constructions and existing apartment retrofits. Old apartment structures have poor thermal performances, resulting in a high energy consumption. The South Korean government initiated retrofitting projects to improve the energy efficiency in old apartments. Apartment owners typically replace old windows with high-performance windows; however, there is still a demand for better and more innovative retrofit methods for a highly improved energy efficiency. This paper proposes an advanced double-skin façade (DSF) system to replace existing balcony windows in old apartments. Considering the cold climate conditions of Seoul, South Korea, it mainly discusses heating energy savings. Three case models were developed: Base-Case with existing apartment, Case-1 with typical retrofitting, and Case-2 with the proposed DSF system. The EnergyPlus simulation program was used to develop simulation models for a floor radiant heating system. A typical gas boiler was selected for low-temperature radiant system modeling. The air flow network method was used to model the proposed DSF system. Five heating months, i.e., November to March, and one representative day, i.e., January 24, were selected for detailed analysis. The main heat loss areas consist of windows, walls, and infiltration. The results reveal that the apartment with the DSF retrofit saves 38.8% on the annual heating energy compared to the Base-Case and 35.2% compared to Case-1.     

Heat planning for fossil-fuel-free district heating areas with extensive end-use heat savings: A case study of the Copenhagen district heating area in Denmark

The Danish government plans to make the Danish energy system to be completely free of fossil fuels by 2050 and that by 2035 the energy supply for buildings and electricity should be entirely based on renewable energy sources. To become independent from fossil fuels, it is necessary to reduce the energy consumption of the existing building stock, increase energy efficiency, and convert the present heat supply from fossil fuels to renewable energy sources. District heating is a sustainable way of providing space heating and domestic hot water to buildings in densely populated areas. This paper is a theoretical investigation of the district heating system in the Copenhagen area, in which heat conservation is related to the heat supply in buildings from an economic perspective. Supplying the existing building stock from low-temperature energy resources, e.g. geothermal heat, might lead to oversized heating plants that are too expensive to build in comparison with the potential energy savings in buildings. Long-term strategies for the existing building stock must ensure that costs are minimized and that investments in energy savings and new heating capacity are optimized and carried out at the right time.     

某节能住宅小区地下水源热泵系统应用的经济性及节能性分析

针对咸阳市某节能住宅小区供冷供热的需求,依据建筑节能规范指标要求,进行围护结构热工设计与计算。结合当地丰富的浅层地下水资源条件,确定了利用地下水源热泵系统对该住宅小区进行供冷供热方案。对系统经济性和节能性进行计算与分析,对比分析了建筑围护结构和空调系统对建筑节能的贡献率,指出了建筑节能集成效益的优势。     

居住建筑固定资产投资项目节能评估中综合能耗计算方法的分析与比较

结合工作实践,发现西安市居住建筑类项目存在不同评估单位计算的年综合能耗量数值差异很大的现象,经比较分析发现差异的主要原因是建筑物采暖耗能量评估计算依据的标准规范不一致。通过对比两种计算方法的内容与指标,认为《城镇供热管网设计规范》采暖热负荷推荐值与项目具体建筑物体形系数、热工性能参数等数值无关,对单体建筑物而言不具有针对性,不是唯一的。因此,建议以《严寒和寒冷地区居住建筑节能设计标准》为节能评估计算依据,方符合国家推行固定资产投资项目节能评估与审查的目的。     

合同能源管理在医院建筑节能改造中的应用

既有建筑开展节能改造是我国现阶段落实节能减排目标、实现可持续发展的关键工作内容之一。合同能源管理作为一种新兴的节能改造商业模式,可以充分调动用能单位开展节能改造的积极性,并充分利用市场资源,最终有效落实节能减排目标。对合同能源管理的概念内涵、发展现状、扶持政策、改造技术以及常见的商业模式进行概述,并以实际的医院建筑改造项目为案例,对其采用合同能源管理的改造方案、商业模式以及风险管控进行介绍,旨在为我国的公共建筑特别是医院建筑的节能改造提供参考依据。     

Residential energy use in one-family households with natural gas provision in a city of the Patagonian Andean region

Residential energy use was studied in one-family houses in the city of Bariloche, in the Patagonian Andean region of Argentina. A survey was conducted of households connected to the natural gas network to correlate use of gas, living area and number of inhabitants per house. The annual average consumption of gas was found to be 169 GJ, and consumption of electricity 8 GJ. This total energy use per household per year is almost double the average value reported for Stockholm, Sweden, although both locations have similar heating requirements. The difference was mainly due to heating energy consumption per unit living space, which in Bariloche was 1530 MJ/m² per year, while in Stockholm the average is around 570 MJ/m² per year. The high energy consumption in Bariloche is explained primarily by the construction characteristics of the buildings, and secondarily by the efficiency of the heating devices used. We were able to conclude that subsidies on natural gas tariffs given to the residential sector do not promote a rational use of the resource. Furthermore, almost 40% of the population (mostly households in poverty) are not connected to the subsidised gas resource, but pay prices for alternative fuels that are between 10- and 15 times higher. Policies to improve buildings and appliances would reduce emissions and make access to energy more equitable.