Retrofit Projects Research Articles

Picture fuzzy multi-criteria group decision-making method to hotel building energy efficiency retrofit project selection

Building energy consumption accounts for a considerable proportion on energy consumption. To reduce building energy consumption, building energy efficiency retrofitting (BEER) based on Energy Performance Contracting mechanism is the most feasible and cost-effective method. With the increase number of BEER projects, BEER project selection has become an essential problem for energy service companies. In this paper, a multi-criteria group decision-making (MCGDM) method is proposed to deal with BEER project selection problem. First, picture fuzzy sets are employed to describe the evaluation information under the complex and uncertain environment. Subsequently, picture fuzzy weighted average operator and Laplace distribution-picture fuzzy order weighted average operator are proposed based on convex combination to aggregate individual evaluations into the overall evaluations. Furthermore, picture fuzzy TOPSIS-based QUALIFLEX method is developed to identify the optimal ranking of alternatives. Moreover, the practicality, effectiveness and advantages of the proposed MCGDM method are illustrated using a case study of hotel BEER project selection and comparative analysis. Finally, conclusions about primary contributions, and future discussions of the proposed method are demonstrated.

Energy Performance and Energy Efficiency Retrofitting in Existing Hotel Buildings – A Review

Tourism is one of the main sources of income in some of the countries around the world. The hotel industry has thus become one of the main industries. Hotels are one of the most energy intensive building categories and the hospitality industry contributes to 2% of the world’s CO2 emissions. At present, new buildings can be made energy efficient even from the design stage but existing buildings consume more energy than the new ones. Building energy efficiency retrofitting techniques should be applied, based on economics, to existing buildings to reduce the high energy consumption. This paper presents a review on energy performance and energy intensive areas of some existing hotel buildings at different tourist destinations in the world. Energy retrofitting technologies should be mainly focused on these energy intensive areas. It also provides a review of common retrofitting technologies and past studies on hotel building retrofits. Finally, it discusses the barriers for retrofit projects and a market mechanism to carry out successful retrofit projects. After seeing more than 50% of energy saving in retrofitted hotels, this paper concludes that all possible retrofitting technologies should be implemented from now on and measure the energy performance both before and after retrofitting.

Innovation in deep housing retrofit in the United Kingdom: The role of situated creativity in transforming practice

There is widespread agreement that the energy efficiency of existing UK housing will need to be improved significantly, to meet future emissions targets and to support the transformation of the energy system. But there is also a recognition of the problematic nature of innovation in the construction industry. The Retrofit for the Future Programme (RftF) was set up in 2009 to address these challenges. This paper investigates the genesis of innovation in construction through the experiences of seven retrofit project teams selected from the RftF programme. While contemporary social practice theories (SPTs) offer a framework for describing socio-technical phenomena, they are insufficient to provide an account of innovation. The conceptual framing of this exploration is therefore based on embedding the notion of situated creativity posited by the pragmatists into SPTs. Reflective focus group and in-depth individual interview methods were used for data collection. The analysis focused on the problems encountered by the project teams. The key insight is that innovation appears to be situational, emerging in the face of contextual complexity, from a combination of the project teams’ commitment to the goals of the RftF Programme and their willingness to move beyond routine, to confront problems, and re-think and re-negotiate solutions. Implications of this insight for Social Practice Theory and methodology for investigation of retrofit innovation are discussed.

Bottleneck Tree Analysis (BOTA) with green and lean index for process capacity debottlenecking in industrial refineries

This paper presents a novel Bottleneck Tree Analysis (BOTA) to cope with the increasing capacities within industrial refineries. BOTA is a clear and concise heuristic graphical debottlenecking method that can accurately pinpoint the process capacity bottlenecks. Coupled with BOTA, four multiple criteria decision-making methods are used for an ensemble with Spearman’s correlation to assess the Green and Lean Index (GLI) of industrial processes. The decision-making tool is formulated to improve operational performance with the consideration for environmental conditions. Empirically, BOTA demonstrated a debottleneck stopping mechanism which can be theoretically explained with the reversed onion model. An additional advantage is that retrofit projects can be guided by BOTA with effective scheduling. From an industrial case study, BOTA improved normalized Global Warming Potential by 94.43 %, normalized energy consumption by 93.09 % and return on investment by 58.36 %. Project implementation by scheduling also reduced payback period from 85 to 66 months.

A bi-objective optimization approach for selection of passive energy alternatives in retrofit projects under cost uncertainty

Abstract Improving energy performance of buildings is of particular importance in new construction and existing buildings. Building refurbishment is considered a practical pathway towards energy efficiency as the replacement of older buildings is at a slow pace. There are various ways of incorporating energy conservation measures in buildings through refurbishment projects. As such, we have to choose among various passive or active measures. In this study, we develop an integrated assessment model to direct energy management decisions in retrofit projects. Our focus will be on alternative passive measures that can be included in refurbishment projects to reduce overall energy consumption in buildings. We identify the relative priority of these alternatives with respect to their non-monetary (qualitative) benefits and issues using an analytic network process. Then, the above priorities will form a utility function that will be optimized along with the energy demand and retrofit costs using a multi-objective optimization model. We also explore various approaches to formulate the uncertainties that may arise in cost estimations and incorporate them into the optimization model. The applicability and authenticity of the proposed model is demonstrated through an illustrative case study application. The results reveal that the choice of the optimization approach for a retrofit project shall be done with respect to the extent of variations (uncertainties) in expected utilities (benefits) and costs for the alternative passive technologies.

Incorporating occupancy data in scheduling building equipment: A simulation optimization framework

A common energy-conservation method involves specifying a schedule in the building automation system (BAS) so that equipment enter a sleep mode or low power mode during predetermined off-shift hours generally defined based on the expected or perceived occupancy schedule. This paper proposes a binary programing optimization model that incorporates actual occupancy patterns for different zones in the building as well as equipment interdependence to systematically determine the optimal schedule for each equipment while maintaining a minimum required service level to meet occupant needs. The model is then integrated into a simulation optimization framework, where historical or simulated occupancy data are used to determine the optimal frequency of schedule updates and the best design option for new buildings or retrofit projects. Through a real-world case study of a university building, we illustrate how the proposed approach harnesses historical occupancy data to select the best option for re-purposing the zones/spaces in the building. The results provide important practical insights by showing the significant potential to improve common practice that typically uses the exact same schedule for all equipment in the BAS. The results further show that the choice of the design option depends on the minimum required service level. The paper also illustrates the importance of updating equipment schedules in response to possible seasonal changes in occupancy patterns throughout the year. All codes and datasets are made available in an open repository to facilitate adoption by practitioners and enable reproducibility of the results for researchers.

Combined Flexibility and Energy Analysis of Retrofit Actions for Heat Exchanger Networks

Retrofitting of industrial process heat recovery systems can contribute significantly to meeting energy efficiency targets for industrial process plants. One issue to consider when screening retrofit design options is that industrial heat recovery systems must be able to handle external variations, e.g. in ambient temperature, in such a way that operational targets are reached. There exist different approaches to incorporate flexibility considerations in the design process of retrofit proposals for heat exchanger networks (HEN). However, due to mathematical complexity, lack of suitable cost data, and difficulty to handle large-scale systems, the adoption of those methods in industrial retrofit projects has been limited. Therefore, this paper proposes to decouple the design and analysis steps in retrofitting processes. This allows well-proven retrofit design methods to be used in the design step to generate different alternatives. These design alternatives are thereafter evaluated in a separate analysis step in which the initial set of designs is narrowed down to one or several design options that are operable and energy efficient for a priori defined variations of operating conditions. The proposed approach is based upon traditional flexibility analysis combined with energy performance analysis. With such performance data available, a fair evaluation over different operating points can be obtained. The proposed approach is used for analysing the flexibility and energy performance of a HEN case study to illustrate its application.

Aspects of using 3-D laser scanning technology in ship retrofit projects

The number of ship retrofit and conversion projects has increased dramatically over the last couple of years, mainly as a result of new international regulations to limit environment pollution. Another driver has been conversion of oil tankers into floating production, storage and offloading (FPSO) vessels as offshore oil and gas production has moved into deeper waters. The need to accurately establish the existing location of equipment and systems onboard ships prior to a retrofit project has lead to an increasing use of 3-D laser scanning. This technology brings benefits as it increases the accuracy of the retrofit design and associated production information and it shortens the time needed for the onboard survey. The paper describes the laser 3-D technology and compares the time allocated to the classical practice of collecting input data onboard of ships with 3-D laser scanning activity, based on review of records from several onboard scanning and subsequent retrofit projects.

Air to water heat pumps for heating system retrofit in urban areas: understanding the multi-faceted challenge

Air has an important role to play as a renewable resource to supply heat in urban areas. The implementation of heat pumps in multifamily buildings represents an important and underexploited development potential. Financial comparison of heating costs depending on building size and heat production technology shows how retrofit projects with air-to-water heat pumps compare to gas. Feedback from experience based on pilot projects presents the various challenges faced and proposes solutions.

Barriers to retrofitting buildings for energy efficiency in South Africa

Literature has established the enormity of energy consumed by buildings. The processes involved in generating and distributing this energy, and most especially its usage is identified as causing a significant adverse environmental impact. As a strategy for enhancing the effectiveness and efficiency of existing buildings through the introduction of new technologies, retrofitting has become another avenue for achieving sustainability in the construction industry. This paper, therefore, seeks to identify the major barriers to retrofitting buildings for energy efficiency in South Africa. A structured questionnaire survey was used as the instrument for data collection. Data for the study were gathered from construction professionals (architects, civil engineers, quantity surveyors, project managers, construction managers, and energy engineers) with experience in building retrofit projects. A quantitative approach to data analysis was adopted using percentage, standard deviation, and mean item score. From the data analysed, the results revealed low income, high investment costs, occupant’s resistance, high upfront cost, and low consumer appeal as the top five barriers. The findings from this study will help improve and encourage retrofitting buildings for energy efficiency which is believed to have the potential of drastically reducing the long-term cost of energy consumption, greenhouse gas emissions and carbon footprint.

Organisational learning in small and medium sized South African energy project organisations

PurposeThe purpose of this paper is to explore, using fine-grained exploratory multi-case studies, organisational learning practices – and associated constraints – impacting the performance of four small- and medium-sized project organisations which deliver energy efficiency projects in South Africa and whose learning practice mixes are of wider significance for the emerging project society in the region.Design/methodology/approachThe unit of analysis is the Energy Efficiency Demand Side Management (EEDSM) programme; a US$104m grant funded the initiative directed at supporting energy efficient retro-fit projects across local municipalities in South Africa. Thematic analysis is undertaken, based on multiple exploratory interviews with project practitioners working for small- and medium-sized EEDSM project organisations.FindingsRecognising the criticality of tacit knowledge as a focus for learning, within unstructured, novel, non-routine and technically specialised learning contexts in particular, the widespread lack of organisational harnessing through linkages to strategy and performance are noted, and advocacy is offered for the development of appropriate learning cultures linked to communities of practice that bring specialists together from across regional project societies.Research limitations/implicationsThe socio-political context of the EEDSM programme, although briefly addressed for its organisational cultural implications, was not given detailed consideration in the exploratory interviews. This would have enhanced the idiographic complexity of the findings, while also reducing prospects for distilling generalisable organisational learning improvement opportunities for emerging project societies. However, the study does not seek to provide evidence for specific learning practice effects on performance as this was not something the interviewees felt able to comment on in significant detail.Originality/valueLearning practice studies for small- and medium-sized project organisations remains sparse, so are studies of business environments within developing countries, in general, or sub-Saharan Africa, in particular. Looking beyond narrow individual project views of performance, the present study’s project society-based business environment is theorised as both constraining and benefiting from the project-learning practices discussed by the respondents.

Analysis of the energy and thermal performance of a radiant cooling panel system with integrated phase change materials in very hot and humid conditions

This study evaluates the energy and thermal performance of a radiant cooling panel system with integrated phase change materials (PCMs) for application in building retrofit projects. The focus is on the energy saving potential of using two different strategies to avoid condensation in very hot and humid climate conditions. The cooling energy consumption of a DOE medium office prototype building model with a conventional all-air system is used as a baseline for comparing the proposed configurations. The results show that the radiant system yielded energy savings of around 48% compared to the all-air system for existing office buildings. Results also show that the proposed system is able to operate only during the night-time, which improves the plant efficiency. Thus, the energy savings are mainly due to a reduction in the energy consumption of the cold generation system and lower energy use for ventilation compared with conventional air systems.

Software solution to design energy-efficient retrofitting projects at district scale

The EU strategies to reduce carbon dioxide emissions highlight the importance of renovating the existing building stock. It is one of the most contributing sectors to these undesired emissions to the atmosphere. The business-as-usual practices for designing energy-efficient retrofitting projects are still too time consuming and imprecise, and their supporting tools are not interconnected, provoking a lack of trust within the sector, particularly from investors. There is a need to improve these practices by reducing the errors and the time required to evaluate retrofitting alternatives to select the most appropriate according to the stakeholders’ priorities. To address this gap, the Optimised Energy Efficient Design Platform for Refurbishment at District Level (OptEEmAL) solution enables the automatic generation of scenarios of energy conservation measures and their simulation and optimisation, based on data provided by the users. This solution automatically launches and connects the processes that the different stakeholders usually carry out in a long period of time. This allows testing a more varied set of solutions and engages stakeholders along the process supported by the integrated project delivery approach. As a result, time is reduced, as well as errors and, therefore, costs, which will lead to increase in efficiency and confidence among stakeholders.

Seismic retrofitting of Māori wharenui in Aotearoa New Zealand

The design of Māori wharenui (meeting houses), refined over the last 180 years, has given rise to a distinctive typology that demonstrates an understanding of tectonic-narrative expression. It is a visual codex designed to be read. Set within the context of pre-disaster readiness, this current study investigated the resilience of Māori buildings and communities through a dual interpretation of seismic, regulatory and historical frameworks. The literature on Māori building technologies scarcely addresses matters of resilience and there is currently no formalized methodology to guide wharenui seismic retrofit practice. Through a macro level analysis of recently completed retrofit projects, this current study identified issues present in current practice. The resulting research presented a pathway for the future development of an approach (to inform methodologies) and strategy (to build capability) founded on the recognition of wharenui as a new category of building within building regulations. It is also recommended that research continues to develop alternative engineered solutions, expert knowledge bases and best practice guidelines. This article is part of the theme issue 'Environmental loading of heritage structures'.

Systematic Simplified Simulation Methodology for Deep Energy Retrofitting Towards Nze Targets Using Life Cycle Energy Assessment

The reduction of energy consumption in the residential sector presents substantial potential through the implementation of energy efficiency improvement measures. Current trends involve the use of simulation tools which obtain the buildings’ energy performance to support the development of possible solutions to help reduce energy consumption. However, simulation tools demand considerable amounts of data regarding the buildings’ geometry, construction, and frequency of use. Additionally, the measured values tend to be different from the estimated values obtained with the use of energy simulation programs, an issue known as the ‘performance gap’. The proposed methodology provides a solution for both of the aforementioned problems, since the amount of data needed is considerably reduced and the results are calibrated using measured values. This new approach allows to find an optimal retrofitting project by life cycle energy assessment, in terms of cost and energy savings, for individual buildings as well as several blocks of buildings. Furthermore, the potential for implementation of the methodology is proven by obtaining a comprehensive energy rehabilitation plan for a residential building. The developed methodology provides highly accurate estimates of energy savings, directly linked to the buildings’ real energy needs, reducing the difference between the consumption measured and the predictions.

Green Resilient City - A framework to integrate the Green and Open Space Factor and climate simulations into everyday planning to support a green and climate-sensitive landscape and urban development

Continued urban growth, densification and the constantly increasing number of days with excessive heat provide challenging conditions for urban green infrastructure (UGI) and intensify the Urban Heat Island effect (UHI). Therefore, new approaches are required to improve the urban ecological function of buildings and to provide high-quality (urban) open spaces that affect the meso- and microclimate in a positive way. Based on the research project “Green Resilient City”, this paper shows how climate simulations can support landscape and urban planning and development. A proof of concept for a multiscale tool set for the evaluation, regulation, and optimization of green and climate-sensitive urban planning projects is the overall aim. The tool-set combines a Green and Open Space Factor, as an urban planning index and controlling instrument, as well as three climate simulation models on different scales in order to harmonize them: the GREENPASS® as an optimization instrument on parcel and neighborhood level, MUKLIMO_3 on neighborhood and city level and Cosmo-CLM as evaluation tools on mesoclimatic and regional level. Several advantages arise from the unprecedented combination of these four instruments: It transfers the use of climate models to the planning process, enables the testing and optimization of different UGIs with a focus on how they can influence the climatic performance of the proposed design of an urban development or retrofit project and serves as a scientific basis for urban planning decisions on a political level.

Opportunities for financing sustainable development using complementary local currencies

Financing building retrofit projects that contribute to climate change mitigation has always represented a significant barrier. With 28% of global emissions coming from existing buildings, it is of paramount importance to carry out retrofit measures that lead to significant reduction of these emissions. Whilst this is perfectly possible to achieve with current methods and current technology, there is no sufficient conventional finance to carry out zero carbon retrofit at scale required for climate change mitigation. The article introduces an alternative and sustainable business model that creates new opportunities for financing zero carbon retrofit of buildings. It demonstrates that the value of solar energy falling on roofs of buildings can become a driver for new local economic systems, and discusses the requirements for practical application.

Devices and strategies: An analysis of managing complexity in energy retrofit projects

Energy retrofits in households are an important means of reducing energy consumption and mitigating climate change. However, energy retrofit rates have generally been lower than expected. As a key reason behind non-adoption, the complexity of energy retrofits can be challenging for adopters to handle. In this article, we study how suppliers and retrofit adopters seek to manage the complexity of an energy retrofit purchase. Using interview and mystery shopping data, the article analyses how the complexity is managed through a variety of complexity management devices (CMD) and complexity management strategies (CMS). We identify four complexity management devices, concretizations that help deal with energy retrofit complexity: characterisations, projections, comparisons and references. In addition, we identify four complexity management strategies for managing complexity: pre-exposure, choice simplification, outsourcing and championing. The contribution of the study is in highlighting the role of complexity management in energy retrofits and how CMDs and CMSs are involved in structuring energy retrofit offerings, business models and energy information. This, in turn, provides impetus for developing measures to ease the complexity of adoption.

Electricity Production from Sugarcane Straw Recovered Through Bale System: Assessment of Retrofit Projects

Sugarcane straw has become available in large quantities in the field due to transition from manual to mechanical harvesting. Straw can be used as fuel for cogeneration systems of sugarcane mills to increase surplus electricity for commercialization. However, the exploitation of straw potential is still limited due to some challenges related to its agricultural recovery and industrial processing. The retrofit (additional installation) of existing sugarcane mills to process straw is an alternative to reduce investment and to allow a gradual utilization of this biomass. In this work, techno-economic and environmental assessment of straw recovery through bale system to increase electricity export was assessed. Two scenarios with straw recovery and processing were defined to take advantage of an existing cogeneration system, considering its operation in the season and off-season periods. An increase of up to 57% on surplus electricity was achieved. Both scenarios resulted in economically feasible alternatives. However, results were very sensitive to the variations on electricity prices and straw costs. In terms of environmental benefits, the bioelectricity presented a great potential to mitigate greenhouse gas emissions compared with natural gas–based electricity. The higher electricity surplus also affects the carbon intensity of ethanol, which can lead to indirect gains when the Brazilian program for biofuels incentive is implemented.

Case-based reasoning approach for supporting building green retrofit decisions

Building green retrofit is considered as an effective means of energy saving and achieving sustainable development goals. The success of a building retrofit is highly dependent on the retrofit strategies used. However, it remains challenging to select appropriate retrofit strategies for a specific retrofit building. There are numerous cases of building retrofit around the world, which can be collected, stored, and analysed. The knowledge gained from these cases could provide a useful reference for making decisions on new retrofitting projects. This study presents a case-based reasoning (CBR) approach to support building green retrofit decisions. A total of 71 retrofit cases in China were collected. The attributes of the retrofitting buildings were identified, including the general building information, component information, and energy and cost information. A synthetic optimisation weighting method was adopted based on both expert opinion and the attribute characteristics. A real retrofit case located in Shanghai was used as a case study to demonstrate the application of the CBR approach. The results indicate that the CBR approach can aid in identifying similar cases from the case database, and extracting valuable information from these. The experience and lessons learned from past cases can guide decision makers in making improved decisions on new green retrofit projects.