Energy-saving Renovation Research Articles

A Thematic Network-Based Methodology for the Research Trend Identification in Building Energy Management

The rapid increase in the number of online resources and academic articles has created great challenges for researchers and practitioners to efficiently grasp the status quo of building energy-related research. Rather than relying on manual inspections, advanced data analytics (such as text mining) can be used to enhance the efficiency and effectiveness in literature reviews. This article proposes a text mining-based approach for the automatic identification of major research trends in the field of building energy management. In total, 5712 articles (from 1972 to 2019) are analyzed. The word2vec model is used to optimize the latent Dirichlet allocation (LDA) results, and social networks are adopted to visualize the inter-topic relationships. The results are presented using the Gephi visualization platform. Based on inter-topic relevance and topic evolutions, in-depth analysis has been conducted to reveal research trends and hot topics in the field of building energy management. The research results indicate that heating, ventilation, and air conditioning (HVAC) is one of the most essential topics. The thermal environment, indoor illumination, and residential building occupant behaviors are important factors affecting building energy consumption. In addition, building energy-saving renovations, green buildings, and intelligent buildings are research hotspots, and potential future directions. The method developed in this article serves as an effective alternative for researchers and practitioners to extract useful insights from massive text data. It provides a prototype for the automatic identification of research trends based on text mining techniques.

Are environmental fiscal incentives effective in inducing energy-saving renovations? An econometric evaluation of the French energy tax credit

Abstract Fiscal incentives have been introduced to encourage households in many countries to undertake energy-saving renovations. This paper assesses the impact of an energy tax credit on (i) renovation rate and (ii) renovation expenditures using French data. We exploit a sharp discontinuity corresponding to the introduction of the French tax credit in 2005 to identify the policy's effects. Results indicate that the tax credit has little effect on the decision to renovate, increasing renovations by 1.09%, ceteris paribus. We find that the presence of free riding reduces the actual effect of fiscal measures. However, this fiscal policy does lead to an increase in renovation expenditures by 21.76%, all things being equal. This suggests that the energy tax credit induces households who are already determined to renovate to perform more substantial energy-saving renovations. We conduct a robustness check using the matching method, which confirms our results.

Research on Construction Technology of Ultra-Low Energy Reconstruction of Existing Buildings

Taking the renovation project of the family building of the Hebei Academy of Building Research as an example. This paper studies the construction process and construction points of the ultra-low energy transformation process, and forms a complete and refined ultra-low energy consumption of existing buildings. Reconstruction of construction technology provides a reference for the promotion and application of ultra-low energy consumption technology in the energy-saving renovation of existing buildings.

Causes of Quality Failures in Building Energy Renovation Projects of Northern China: A Review and Empirical Study

Building energy renovations can effectively improve the environmental performance and energy sustainability of existing buildings. From 2007 onwards, the Chinese government has promoted energy-saving renovations of existing urban residential buildings. Nevertheless, various quality failures happen during the construction period in energy-saving renovation projects of residential buildings. Yet, the causes and their characters remain largely unknown. Through a literature review, this paper investigates the causes of quality failures. Validated through experts’ interviews, a total of 18 causes were identified in building energy renovation projects. These causes were analyzed from two main aspects: the importance of a cause (related to impact and frequency), and the level of effort required to address a cause (related to origin and scale), using both a questionnaire survey and a focus group. The results indicate that the critical causes of quality failures are working under high-cost and high-time pressure, adverse natural conditions, fraud of construction companies, incomplete construction site survey, poor checking procedures of supervisors, poor operational skilled workers, inadequate equipment performance, lack of experienced project managers, and incomplete building information in projects. The causes were classified as external and internal causes of building energy renovation projects. The outcome of this paper should aid policy makers and project coordinators to focus on critical causes of quality failures, and to develop effective actions and policy interventions to achieve successful renovation projects with high-quality performance.

Integrated optimization study of hot water supply system with multi-heat-source for the public bath based on PVT heat pump and water source heat pump

The public bath is the emphasis target of energy-saving renovation of existing public buildings in China. In that case, the integration of the hot water supply system according to the characteristics of heat sources should be studied and optimized to improve the comprehensive energy efficiency and the hot water production of the system. This paper analyzed and remedied the deficiencies of several common hot water supply systems with multi-heat-source, introduced a novel hot water supply system with multi-heat-source based on PVT (photovoltaic and thermal) heat pump and water source heat pump, and then carried out the integrated optimization research of this new system. The main studies include: (1) Established the novel hot water supply system with multi-heat-source and the calculation model of system heating characteristic. (2) Introduced the evaluation method of the comprehensive energy efficiency and economic performance for the hot water supply system with multi-heat-source. (3) Aiming at reducing the total cost of hot water supplying, the integration optimization ideas of system were proposed. By above methods, the integrated optimization of the existing North Mountain Public Bath in Dalian University of Technology was conducted. On one hand the daily production of the existing hot water supply system in the public bath is increased from 80 t to 146 t, the supply capacity of hot water is significantly promoted. On the other the total cost of hot water supplying decreases from 9.6 RMB/(t year) to 4.9 RMB/(t year), the comprehensive energy efficiency and the economic performance of system is improved.

Indoor Temperature Improvement and Energy-Saving Renovations in Rural Houses of China’s Cold Region—A Case Study of Shandong Province

With the continuous implementation of a plan for reconstruction of “Beautiful Countryside” in China, the rural environment and appearance of rural houses have been significantly improved. However, those houses in cold areas of China have great trouble with indoor temperature and heating-related energy consumption. After investigating the current situation of the layout, building envelope, indoor temperature, and energy consumption of the rural houses renovated by the plan of “Beautiful Countryside” in Shandong Province, this paper puts forward the improvement measures of raising indoor temperature and reducing energy consumption. On this basis, a typical rural house was selected, and DesignBuilder was utilized to simulate the effects before and after the application of different renovation measures for this house. The results show that the main way to raise indoor temperature and reduce energy consumption is to improve the thermal insulation performance of the building envelope, including renovation of the roof, exterior walls, doors and windows, and attached sunspace. In addition, combined with the achievements of “Beautiful Countryside” reconstruction, this paper shall propose specific renovation practices which are suitable for different rural houses. Based on the level of economic development in rural areas, it also puts forward some feasible renovation paths for different rural areas, and further provides references for other areas to carry out relevant work in the future.

Transaction costs as a barrier in the renovation decision-making process: A study of homeowners in the Netherlands

The renovation of housing stock in the Netherlands has the potential to help achieving the country’s climate change targets. However, there are non-monetary Transaction Cost (TC) factors, such as searching for information and finding a reliable professional/contractor, that present barriers to householders when making the decision to renovate or not. This study evaluates the impact of the transaction costs on the renovation decision-making process for two groups of householders, current renovators and potential renovators, and for three types of renovations, exterior renovations, interior renovations, and energy efficiency renovations. The study analyses householder renovation decisions in relation to TC barriers at different stages of the renovation processes. The data was collected from a survey of 3,776 homeowners in the Netherlands. The main identified TC barriers were found to be at the consideration, decision, and execution phases of the renovation decision-making process, and are: finding a reliable professional/contractor to do exterior renovations, determining costs for interior renovations, and finding ways to increase the energy efficiency of the house using energy-saving renovations. The main sources of information for householders are construction stores/Do It Yourself (DIY), installations and maintenance companies for exterior and energy efficiency renovations, while for interior renovations it is construction stores/DIY companies, Internet, and recommendations from family/friends. The findings from this study contribute to more effective management and distribution of both information and financial resources in relation to the renovation of housing stock.

Younger vs. older homeowners in building energy-related renovations: Learning from the Portuguese case

There is still a little recognition in policies that homeowners cannot be assumed as one homogeneous group when it comes to their decision for energy-saving renovation. The interest in energy efficiency varies among these homeowners depending not only on personal and contextual factors but also on everyday life activities and social practices. Some studies suggest that the homeowner’s life stage have a significant role in shaping this interest. This study aims to understand the influence of the homeowner’s age on the motivation for energy-related renovations of Portuguese owner-occupied single-family buildings and how this age is linked to the home-related and social practices that may encourage these renovations. A survey and a structured observation method were used. The younger Portuguese homeowners seem to be more environmentally conscious and adopt “little-by-little” energy renovations, even if less visible to the community. For the older, despite higher incomes, usual motivational arguments do not seem to work. If energy-related renovations are associated to some particular issues about aesthetics, indoor comfort conditions and sentimental meanings given to the home, these renovations are more likely to happen. However, both can be influenced by key moments in their life that trigger the renovation process.

Heat consumption analysis and energy-saving renovation of building heating in high sunshine heating area

In order to explore the effect and influence of energy-saving renovation on buildings in high sunshine heating area, the method of visit survey is used. The main scope of reconstruction includes: building windows, walls, door joints, pipe net-work, insulation measures, etc. The heat consumption of buildings, the comprehensive effect of improvement, and the satisfaction of residents are studied. The results show that after the energy-saving renovation of buildings and equipment in the heating area, compared with before the renovation, the residents' awareness of saving heating has been greatly improved and the waste has been significantly reduced. With the decrease of heating economic expenditure, people are more satisfied with energy-saving renovation. Both heating companies and individual users have been relatively large expenditure reduction. To sum up, it is very important to improve the energy efficiency of buildings in high sunshine heating area. After the energy-saving renovation of the building, not only the awareness of saving is improved, but also the consumption of resources are reduced, so that more people can enjoy the warmth. A win-win situation in the cost of users and heating companies is achieved. This study has a positive effect on the follow-up research of building energy-saving renovation in heating area.

Renovation Measures for Energy-saving Skin of Existing Buildings

As an important part of internal and external connections, the building skin can not only beautify the appearance of the building, but also improve the energy-saving performance of the building. This article aims to sort out the specific measures of skin energy-saving renovation from three aspects: the renovation of the peripheral protection structure, the energy-saving renovation of windows and the addition of shading measures, and analyses them in combination with typical renovation cases.

Field Test and Economic Analysis of Energy-Saving Renovation for an Old Nursery Pig Building in Beijing, China

HighlightsAn old nursery pig building was retrofitted to potentially improve envelope insulation capacity.A mathematical theory based on coal consumption was established to evaluate energy efficiency of insulation renovation for a nursery pig building.The heat loss of the nursery pig house with 90-mm-thick extruded polystyrene boards was 60% lower than that without the materials.Ground source heat pump and air source heat pump are economical and environmental-friendly heating systems.Abstract. Appropriate renovation of old buildings is critical for energy-efficient pig production. Currently, energy consumption, especially coal consumption, keeps on rising in the production. Therefore, it is essential to develop energy-saving renovation methods for old nursery pig buildings and use cleaner heating energies. A mathematical theory based on coal consumption was established to evaluate energy efficiency of insulation renovation. Two nursery pig houses were tested in this experiment. One was the retrofitted house with the 90-mm-thick extruded polystyrene boards embedded onto outer walls, and the other one was served as a control house without those insulation materials. The results show that the air temperature and inside surface temperature of the retrofitted house were significantly higher than those of the control house in winter. Therefore, though adding insulation layers to walls, the envelope insulation capacity was improved. Meanwhile, the heat loss of the retrofitted house was 60% lower than that of the control house (11.08 W m-2 vs. 27.93 W m-2), when the theoretical ventilation rate was 1560 m3 h-1. In addition, with the prohibition of the coal usage in forseeable future of China, the ground source heat pump and air source heat pump can be economical solutions for heating systems with clean and renewable energy. Keywords: Air source heat pump, Extruded polystyrene board, Ground source heat pump, Heating, Thermal insulation.

Simulation and experimental study of phase change cooling and heating wall radiation air conditioning system

This paper presents a case study of phase change cooling and heating wall radiant (PC-CHWR) air conditioning system application in an energy-saving renovation project in a laboratory in Wuhan, Hubei province in China. To test the thermal performance of the system, the PHOENICS software was utilized to simulate and analyse the indoor thermal environment in the laboratory under both winter and summer operating conditions. In addition, field experiments were also conducted under winter operation condition. By comparing the results between numerical simulation and field experiment, it is found that thermal performance of the PC-CHWR air conditioning system evaluated by these two evaluation methods are quite match. Moreover, the results also show that the PC-CHWR system can meet the cooling and heating load of the building within the acceptable range.

Influence of situational factors on household’s energy consumption behaviour

PurposeThis paper aims to present a systematic scoping review of the influences of some situational factors on the energy consumption behaviour of households. Household’s energy choice and manner of utilization define its energy consumption behaviour; it is a key factor in determining the energy efficiency of households. Despite the energy-efficient technological innovations and awareness on environmental/health implications of using certain energy sources and technologies, households still use inefficient, traditional energy sources and technologies. Some researchers have attempted to use economic and psychological theories to explain the situation with the hope of achieving a change in behaviour towards sustainable energy utilization but to no avail. This is because the theories fail to consider situations beyond individuals or households. A clear understanding of situational factors and how they influence household energy behaviour will provide information that will aid deeper research and policy formulation towards sustainable energy behaviour of households.Design/methodology/approachA scoping systematic review of available literature regarding real-life cases in both developed and developing countries was carried out to determine the possibility of situational factors affecting household energy choices and utilization.FindingsThe result of the review showed that situational factors have a significant influence on household’s energy consumption. The main policy implications observed are the need for laws that will encourage energy-saving renovations in houses, make compulsory the provision of recreational facilities in residential areas to reduce in-home energy consumption. The need for increased access to electricity and other efficient energy sources and cooking technologies has also been observed. Intensive awareness campaigns are required to disabuse the minds of people about cultural issues that mitigate improved cook stove adoption.Originality/valueThe paper provides information on the influence of some of the factors, which affect energy consumption in households, which fluctuate depending on the current situation of the consumer and are time-bound (situational factors). The information will help policymakers and regulators to understand the influence of situational factors on household energy consumption, thereby enabling them to make policies that will enhance sustainable energy consumption.

Study on Comprehensive Evaluation on Green-targetedEnergy-saving Renovation Design for Existing Buildings

The renovation for existing buildings will be a trend for architectural transformation in the future. The selection of architectural design plan is a vital step for determining the effect of energy-saving renovation. Based on the analysis of renovation evaluation system for existing industrial buildings and the energy-saving renovation target for existing buildings, this paper sets up the evaluation criteria and factors and determines weight by adopting AHP to produce a quantified evaluation model, as well as makes a practical verification for a specific renovation design case.

Study on building performance considering climate characteristics for university facility in Japan

This study was investigated the building performance of each area for university facilities. The purpose is to propose optimal building performance for each area. As the background, the target building needs the energy-saving renovation. The target building has been built for 25 years and aged. In addition, the primary energy consumption of the target building is larger than the primary energy consumption of standard university facilities. Therefore, it is necessary to renovate buildings and facilities, and plans should be made to save more energy. This research method was examined changing the building performance for each area by using the Building Energy Simulation Tool (BEST) program of the energy simulation. Building performance is the thermal insulation of the outer wall and the type of glazing. As a result, In Ube, primary energy consumption tends to increase if thermal insulation performance is increased too much. In Sapporo, primary energy consumption tends to decrease as thermal insulation performance increases. In Naha, it turned out that increasing the thermal insulation performance is not effective.

Identification of Quality Failures in Building Energy Renovation Projects in Northern China

Building energy renovations contribute significantly to energy sustainability and environmental protection. These advantages have increased the importance of renovating existing residential buildings in many countries. In China, the government has supported the energy-saving renovation of existing urban residential buildings since 2007. However, quality failures, which do not meet the technical requirements, occur during construction processes in building energy renovation projects. Although quality failures are regarded as a crucial problem in building energy renovation projects, the identification of quality failures and their sources, likelihood, impacts, and causes remain mostly unknown. This paper investigates the nature of quality failures in building energy renovation projects. A total of 25 quality failures were first identified through five cases, and interviews with six experienced construction professionals in China. A questionnaire survey was further conducted to evaluate the frequency of quality failures. The results show the nature of quality failures that arise during construction and their sources, occurrence frequency, causes, and impacts. The research reveals that quality failures are caused by defaults by workers; inadequate checking procedures; incomplete construction site surveys; inaccurate design work; fraud of construction companies; and inefficient cooperation between different departments. Above all, the behaviors of the main actors are responsible for poor construction quality. Additionally, emphasis on quality control during the renovation preparation stage is critical to ensure that quality failures are reduced in numbers and severity.

Understanding and Practice of Room Temperature Control Method Based on Energy Saving Reconstruction of Public Buildings

In order to respond to national energy conservation and environmental protection policies, green building development strategies should be implemented in urban public buildings construction, and large-scale project energy-saving renovation plans should be implemented from the perspective of energy conservation. Different projects can adopt different energy-saving control methods according to actual conditions and adopt different control strategies, but the ultimate goal is to change the current situation of large energy consumption, high utilization efficiency, noise pollution, water pollution and air pollution emissions. Building energy-saving renovation and technical control, effectively improves the building energy-saving level, achieves energy-saving and consumption-reduction goals, and gives full play to the value of various resources. At the same time, the energy-saving renovation project can also help enterprises to obtain the maximum economic and social benefits and promote the sustainable development of the construction industry. In view of this, this paper will talk about how to achieve energy-saving goals in the energy-saving renovation of public buildings from the aspects of energy-saving design of indoor supporting facilities, energy-saving design of walls, energy-saving design of doors and windows and roofing energy-saving design, and how to achieve reasonable control of room temperature.

An energy planning oriented method for analyzing spatial-temporal characteristics of electric loads for heating/cooling in district buildings with a case study of one university campus

Accurate grasp of district power demand is of great significance to both sizing of district power supply and its operation optimization. In this study, an index system has been established and visualized through a Geographic Information System, for revealing both temporal and spatial characteristics of district power loads caused by heating/cooling systems, including load level and fluctuation characteristics, spatial distribution of electric loads, and load coupling relationships between individual buildings and the district. Principal component analysis was applied to identify the buildings with significant impact on district load management. Using this method, the spatial-temporal characteristics of electric loads caused by heating in one university campus in China were analyzed. The results showed that building type and the operation modes had great effects on the level and volatility of the district electric load caused by heating. Buildings with high load levels and strong coupling with the peak district electric load, such as academic buildings, often had a major impact on the power demand of the district. Therefore, they were considered as key targets for energy-saving renovation and operation optimization. Buildings with large load fluctuation, such as teaching buildings, could contribute to the peak load shaving by adjusting the heating systems’ operation.

How to evaluate the efforts on reducing CO2 emissions for megacities? Public building practices in Shenzhen city

China’ cities have made great efforts to seek effective measures to encourage and promote energy-saving building practices, for decades. Shenzhen, a fast-growing megacity in Southern China, has been one of the first practitioners to vigorously promote sustainable development in the building sector, for over 15 years. This study was therefore designed to employ the life cycle assessment approach to quantify the efforts of Shenzhen’s public building practices, and evaluate its real ‘achievement’ by quantifying the CO2 emissions (CO2e) reduction over the past decades. The results show that the total CO2e from public buildings sectors in Shenzhen city have increased rapidly, from 15 Mt in 2005 to 22 Mt CO2e in 2016, because of the fast growth of public buildings’ construction activities. However, current ‘low-carbon’ efforts have only reduced CO2e by approximately 0.5 Mt annually over the past decade, and thus could not offset the rapid growth arising from the increase in floor area. This is hardly enough to contribute proportionally to the city’s overall reduction target. In addition, we conducted a scenario analysis to determine the optimal mitigation measures. The results imply that accelerating the energy-saving renovation of existing buildings is a promising approach and could meet the pressing mitigation needs. These findings could not only inform evidence-based policies to promote the adoption of energy-saving building technologies in Shenzhen, but also shed light on sustainable transition in other megacities.

Full-scale Studies of Improving Energy Performance by Renovating Historic Swedish Timber Buildings with Hemp-lime

With an increased focus on reducing greenhouse gas emissions, energy saving is of great importance in all sectors of society. EU directives set targets for member states to reduce energy use in buildings. Energy saving in historic buildings requires special measures, balancing energy-saving renovations against the preservation of heritage values. Traditional constructions are open to vapor diffusion and generally work differently from modern constructions. Modern materials in traditional constructions sometimes damages the original material as they are usually diffusion-tight. The aim of this study was to investigate whether hemp-lime could be used as an insulation material to improve the energy efficiency of historic timber building envelopes with a rendered façade in Sweden. The objective was to determine the actual energy savings for space heating. An additional objective was to determine the actual thermal transmittance and to study thermal buffering through in-situ measurements in a full-scale wall renovated with hemp-lime. Two full-scale wall sections were constructed at the Energy and Building Design laboratory at Lund University: A traditional post-and-plank wall with a lime render (80 mm), and a post-and-plank wall with a hemp-lime render (90 mm). Energy use for space heating was monitored continuously over a period of one year. The wall with a hemp-lime render required 33% less energy for space heating than the traditional post-and-plank wall with a lime render. This was accomplished without changing the framework, appearance or material in the render and without drastically changing the hygric properties of the façade. From the gathered data, the thermal transmittance (U-values) for both walls was calculated using two different methods, one based on material properties and the other based on energy use data. For both walls, thermal transmittance based on actual energy use data during the heating period was lower than what was expected from their material properties. This indicates that more material properties than thermal conductivity and material thickness need to be taken into account when performing energy use calculations. With hemp-lime, a renovation can be accomplished without damaging the timber structure and wooden slats, and it can be done with local traditional materials and building methods with no difference in appearance to a traditional lime render. This allows for heritage values to be preserved, while also allowing the building to comply with modern standards and with increased thermal comfort and reduced energy use.