This study evaluates energy performance and economic analysis of variable refrigerant flow (VRF) systems in U.S. climate locations using widelyepted whole building energy modeling software, EnergyPlus. VRF systems are known for their high energy performance and thus can improve energy efficiency in buildings. To evaluate the energy performance of a VRF system, energy simulation modeling and calibration of a VRF heat pump (HP) type system is performed using the EnergyPlus program based on measured data collected from an experimental facility at Oak Ridge National Laboratory (ORNL). In the calibration procedures, the energy simulation model is calibrated, according to the ASHRAE Guideline 14-2014, under cooling and heating seasons. After a proper calibration of the simulation model, the VRF HP system is placed in U.S. climate locations to evaluate the performance variations in different weather conditions. An office prototype building model, developed by the U.S. Department of Energy (DOE), is used with the VRF HP system in this study. This study also considers net-zero energy building (NZEB) design of VRF systems with a distributed photovoltaic (PV) system. The NZEB concept has been considered as one of the remedies to reduce electric energy usages and achieve high energy efficiency in buildings. Both the VRF HP and VRF heat recovery (HR) system types are considered in the NZEB design, and a solar PV system is utilized to enable NZEB balances in U.S. climate locations by assuming that net-metering available within the electrical grid-level. In addition, this study conducts life cycle cost analysis (LCCA) of NZEBs with VRF HP and HR systems. LCCA provides present values at a given study period, discounted payback period, and net-savings between VRF HP and HR systems in U.S. climate locations. Preliminary results indicate that the simulated VRF HP system can reasonably predict the energy performance of the actual VRF HP system and reduce between 15-45% for HVAC site energy uses when compared to a VAV system in U.S. climate locations. The VRF HR system can be used to lower building energy demand and thus achieve NZEB performance effectively in some hot and mild U.S. climate locations.

The need to transition the global economy to net zero greenhouse gas emissions is clear. Commitments made by the majority of the world’s governments declare that a global net zero economy should be achieved by the middle of the century. What is less clear is how this transition should take place, or how these commitments impact companies. This paper explores senior management perspectives on a net zero transition, identifying drivers, enablers, and barriers to transitioning effectively. In line with Kurt Lewin’s work, we collectively refer to these as forces. Through 11 in-depth interviews and a quantitative survey to managers across several industries and geographies, we identify, rank, and visually conceptualise 26 forces that act on companies in the context of a net zero transition. The strongest driving force is ‘Societal awareness of climate change and net zero targets’, while the biggest current constraining force is ’Business priorities’. The force considered to have the single biggest potential impact is ‘government disincentives and bans’. Based on the collective analysis of our findings, there are possible policy implications that could be explored further in order to successfully manage a transition to net zero.

The road to energy-efficient housing is not without cracks and potholes. Many building stakeholders have pointed to the discrepancies that exist between simulated and measured efficiency results, where some have called it a post-occupancy gap, others have called it an energy efficiency information gap. The research presented in this thesis addresses that gap by detailing the results of two exploratory case studies of affordable housing projects in Virginia across three manuscripts. The data utilized in the first manuscript includes measured data collected at the second level through the NEXI energy monitoring and feedback device, wherein we used descriptive statistics to investigate the impact of temperature on energy use over different timeframes. We had anticipated our findings may not all be consistent with previously existing studies. We found this to be true in many cases, but we also discovered interesting contradictions to our assumptions. This study thereby investigates the gap in energy performance within net-zero buildings and contributes to the existing body of literature by presenting the findings of this unique study. The data utilized in Manuscript 2 and Manuscript 3 was utility data, which was reported as end-of-use monthly consumption values. We were able to investigate the impact of 3 different HVAC systems energy use by evaluating the energy and cost performance before and after the installation of newer, more efficient systems. We found that although all systems were performing below anticipated standards, the one-stage system outperformed in terms of efficiency, and the second-stage system outperformed in terms of cost. The findings in these studies emphasize the importance of energy education for residents to achieve greater efficiency gains. / Master of Science / Humans are complex beings; hence the buildings they inhabit are complex systems. While breakthroughs in simulating, designing, and constructing high-performance buildings as well as advanced energy use technologies have been promising, many have fallen short of their ambitious goals primarily due to the complexity of building occupant behavior. Achieving energy efficiency requires thorough research before design and construction, the use of advanced technologies, and the incorporation of behavior-driven energy use dynamics. Furthermore, with the breadth of literature to support the delivery of individualized energy information in real-time to residents comes the opportunity to investigate further the impact of advanced technologies in high performing buildings that have fallen short of their optimistic design goals. This thesis consists of three manuscripts, which describe two exploratory case studies of high-performance residential homes in Virginia's affordable housing sector. The first manuscript, a journal paper, investigates the individual HVAC energy use of six senior residents, wherein we explore the interplay between temperature, energy use, and age across different timeframes. We find that, across different timeframes, energy use for senior citizens remains relatively consistent in high-performance homes. The second and third manuscripts are conference papers, which have been presented on and published in the respective conference proceedings. We quantitively investigated the energy performance of energy-efficient HVAC systems and compared predicted results and measured results. In conclusion, we hope to contribute to the body of literature, which investigates shortcomings in achieving energy-efficiency within high-performance homes.

Buildings have a significant impact on energy usage and the environment. Much of the research in architectural sustainability has centered on economically advanced countries because they consume the most energy and have the most resources. However, sustainable architecture is important in developing countries, where the energy consumption of the building sector is increasing significantly. Currently, developing countries struggle with vaccine storage because vaccines are typically warehoused in old buildings that are poorly designed and wasteful of energy. This thesis created and studied a decision support tool that can be used to aid in the design of economically feasible Net Zero Energy vaccine warehouses for the developing world. The decision support tool used a simulation-optimization approach to combine an optimization technique with two simulation softwares in order to determine the cost-optimal design solution. To test its effectiveness, a new national vaccine storage facility located in Tunis, Tunisia was used. Nine building parameters were investigated to see which have the most significant effect on the annual energy usage and initial construction cost of the building. First, tests were conducted for two construction techniques, five different climates in the developing world, and three photovoltaic system prices to gain insight on the design space of the optimal solution. The results showed the difference between an economically efficient and economically inefficient Net Zero Energy building and the results were used to provide generalized climatic recommendations for all the building parameters studied. The final test showed the benefits of combining two optimization techniques, a design of experiments and a genetic algorithm, to form a two-step process to aid in the building design in the early stages and final stages of the design process. The proposed decision support tool can efficiently and effectively aid in the design of an economically feasible Net Zero Energy vaccine warehouse for the developing world.

abstract: Schools all around the country are improving the performance of their buildings by adopting high performance design principles. Higher levels of energy efficiency can pave the way for K-12 Schools to achieve net zero energy (NZE) conditions, a state where the energy generated by on-site renewable sources are sufficient to meet the cumulative annual energy demands of the facility. A key capability for the proliferation of Net Zero Energy Buildings (NZEB) is the need for a design methodology that identifies the optimum mix of energy efficient design features to be incorporated into the building. The design methodology should take into account the interaction effects of various energy efficiency measures as well as their associated costs so that life cycle cost can be minimized for the entire life span of the building. This research aims at developing such a methodology for generating cost effective net zero energy solutions for school buildings. The Department of Energy (DOE) prototype primary school, meant to serve as the starting baseline, was modeled in the building energy simulation software eQUEST and made compliant with the requirement of ASHRAE 90.1-2007. Commonly used efficiency measures, for which credible initial cost and maintenance data were available, were selected as the parametric design set. An initial sensitivity analysis was conducted by using the Morris Method to rank the efficiency measures in terms of their importance and interaction strengths. A sequential search technique was adopted to search the solution space and identify combinations that lie near the Pareto-optimal front; this allowed various minimum cost design solutions to be identified corresponding to different energy savings levels. Based on the results of this study, it was found that the cost optimal combination of measures over the 30 year analysis span resulted in an annual energy cost reduction of 47%, while net zero site energy conditions were achieved by the addition of a 435 kW photovoltaic generation system that covered 73% of the roof area. The simple payback period for the additional technology required to achieve NZE conditions was calculated to be 26.3 years and carried a 37.4% premium over the initial building construction cost. The study identifies future work in how to automate this computationally conservative search technique so that it can provide practical feedback to the building designer during all stages of the design process. / Dissertation/Thesis / Masters Thesis Built Environment 2016

abstract: The building sector is responsible for consuming the largest proportional share of global material and energy resources. Some observers assert that buildings are the problem and the solution to climate change. It appears that in the United States a coherent national energy policy to encourage rapid building performance improvements is not imminent. In this environment, where many climate and ecological scientists believe we are running out of time to reverse the effects of anthropogenic climate change, a local grass-roots effort to create demonstration net zero-energy buildings (ZEB) appears necessary. This paper documents the process of designing a ZEB in a community with no existing documented ZEB precedent. The project will establish a framework for collecting design, performance, and financial data for use by architects, building scientists, and the community at large. This type of information may prove critical in order to foster a near-term local demand for net zero-energy buildings. / Dissertation/Thesis / Appendix M - Simulation and Weather Data / M.S. Built Environment 2014

The Swedish government set a climate goal until the year 2045, to not produce any greenhouse gases until 2045. This study is based on the problems surrounding the climate impact from the construction and real estate sector in Sweden. The construction company Skanska has made a major contribution with the recently new project Juvelen, which today is Sweden's most sustainable building. The demand for constructing buildings with lesser environmental impacts is increasing and constructions as Juvelen may be an important factor to achieve climate goals. Purpose: This study was done to determine the carbon dioxide emissions during the construction phase of Juvelen, which includes the production phase and transports to the construction site, as well as the operational phase. Method: This study is based on a literature study, case study, and a reference object. During the case study, interviews were conducted with various people who have participated in the production of Juvelen. The carbon dioxide calculations consisted of EPD reports obtained from Strängbetong and VSAB. The carbon dioxide calculations for the operational phase were performed through different scenarios with three different scenarios types of energy. Results: The result for Juvelen's carbon dioxide emissions during the construction phase, based on the quantitative data that had obtained from Strängbetong and VSAB, was approximately 3,568 tonnes of CO2e. Renewable High had an emission of 96,472.61 kg CO2e during the 50-year analysis period. Renewable Medium received a sum of 2,519,339.7 kg CO2e and Renewable Low 11,961,913.29 kg CO2e. The 100-year analysis period for the operational phase showed the double value of the 50-year analysis period. Based on the current study and an interview with Ambjörn Gille, it appears that Skanska is making efforts to achieve climate goals by 2045. Conclusions: The conclusion that the work came to was that to achieve the climate goal of net-zero emissions, its necessary that the entire construction and real estate sector needs to adapt, apply new and innovative technology. The differences that emerged from the comparison of the production, operating phase for Juvelen were the choice of material, construction process, and method for construction of Juvelen and the choice of energy scenario.

Industries have faced challenges trying to lower carbon emissions and reach climate goals solely with energy efficiency and renewable energy sources but there are still some emissions that will not be mitigated by this. The purpose of this work has been to evaluate bio-energy with carbon capture and storage with co-combustion in a current study as a way to breach the gap and achieve net zero emissions on AstraZenecas production site Snäckviken. A carbon audit based on GHG Protocol has been performed to evaluate the total emissions at the site. Energy calculations were performed based on the possibilities of co-combustion with waste solvent and biofuel to produce process steam. With the flue gas characteristics for the combustion, calculations for a post combustion carbon capture plant using MEA solvent was made. An economic evaluation has been performed based on a reference plant and carbon captured for the current study. The results showed that the carbon capture lowered the emissions for the production site from 1 020 tons CO2 per year to - 2 400 tons CO2 at a cost of 1 360 SEK/tons CO2. The CO2 avoidance cost was high compared to other studies due to lower capacity. However, great savings could be m ade from handling the waste solvent on site instead of paying for the destruction of the waste. Therefore, a carbon capture plant could still be feasible for the current study.

In response to the ever-intensifying urgency for environmental preservation, the imperative for sectors with substantial carbon footprints to adapt and drive the transition to a low carbon economy is apparent. Sustainability transitions, signifying systemic changes towards sustainable socio-technical systems, emerge as critical in this context, especially within the banking sector. This industry, anchored by its pervasive Information Technology (IT) infrastructure, stands as a key actor in the paradigm shift towards global sustainability. This study investigates the implications of the global transition towards net-zero emissions by 2050 for the IT strategy of banks. This transition necessitates significant changes in the banking sector’s practices, with a particular focus on reducing energy consumption and promoting sustainable operations. The paper presents an in-depth investigation of the factors that banks need to address when adapting their IT strategy to align with these imminent changes. The research methodology followed a qualitative research design, with semi-structured interviews conducted among banking sector practitioners serving as the primary data collection method. Additionally, the study applied the Technological-Organizational-Environmental (TOE) framework to analyze the adoption of sustainable practices in the banking sector. This framework allowed for a comprehensive understanding of the multifaceted nature of the transition towards net-zero emissions, considering the intertwined aspects of technology, organization, and environment. The findings of this research reveal significant insights into the key drivers and strategies required for banks as they make decisions about their IT strategies, particularly in response to the transition towards net-zero emissions. The urgency of environmental sustainability and its integration into strategic planning have emerged as primary drivers, leading to the adoption of Green IT for balancing operational efficiency with environmental responsibility. This strategy has influenced banks’ responses and adaptation by prompting introspective resource management, integrating sustainability into organizational culture, and shaping an environmentally conscious workforce. In conclusion, despite facing various complexities, banks are demonstrating resilience and adaptability in their transition towards sustainability, indicating a future of continuous innovation and transformative practices firmly rooted in sustainability. The findings from this research significantly contribute to the existing body of knowledge, offering deeper insights into the interplay between banking practices and the urgent transition towards net-zero emissions. Future research could further enrich this understanding byassessing the effectiveness of banks’ sustainability initiatives, their achievements against set sustainability targets, and the evolving role of Green IT in driving sustainable banking. / Det växande behovet av miljömässig hållbarhet markerar tydligt nödvändigheten för sektorer med storakoldioxidavtryck att anpassa sig och driva övergången till en ekonomi med minskade koldioxidutsläpp. Övergången till hållbarhet, som innebär systematiska förändringar mot hållbara socio-tekniska system, framstår som avgörande i detta sammanhang, särskilt inom banksektorn. Denna bransch, förankrad av sin omfattande IT-infrastruktur, är en viktig aktör i det paradigmskifte som leder mot global hållbarhet. Denna studie undersöker vad den globala övergången mot nettonollutsläpp fram till 2050 innebär för bankernas IT-strategier. Denna övergång kräver omfattande anpassningar inom banksektorn, med särskild inriktning på att minska energiförbrukningen och främja hållbara verksamhetsmetoder. Rapporten presenterar en djupgående undersökning av de faktorer som banker behöver ta hänsyn till när de anpassar sin IT-strategi för att möta dessa förestående förändringar. Studiemetoden följde en kvalitativ forskningsdesign, med semistrukturerade intervjuer genomförda bland experter och yrkesverksamma inom banksektorn som den primära metoden för datainsamling. Studien applicerade dessutom ramverket Technological-Organizational-Environmental (TOE) för att analysera införandet av hållbara praxis i banksektorn. Detta ramverk möjliggjorde en omfattande förståelse för den flerdimensionella naturen av övergången mot nettonollutsläpp, med hänsyn till de sammankopplade aspekterna av teknik, organisation och externa faktorer. Studiens resultat ger värdefulla insikter om de huvudsakliga drivkrafterna och strategierna som bankerna behöver för att fatta beslut om sina IT-strategier, särskilt i samband med övergången till nettonollutsläpp. Det kritiska behovet av miljömässig hållbarhet och dess integrering i strategisk planering har vuxit fram som centrala drivkrafter, vilket har lett till att Grön IT har antagits för att balansera operativ effektivitet med miljömässigt ansvarstagande. Denna strategi har påverkat bankers respons och anpassning genom att stödja självgranskande resurshantering, integrera hållbarhet i organisationskulturen, och forma en miljömedveten arbetskraft. Sammanfattningsvis, trots mångfald av utmaningar, visar banker motståndskraft och anpassningsförmåga i sin övergång mot hållbarhet, vilket indikerar en framtid av kontinuerlig innovation och omformande metoder som är starkt förankrade i hållbarhet. Resultaten från denna studie bidrar till det befintliga kunskapsfältet, och erbjuder djupare insikter i samspelet mellan bankpraxis och den kritiska övergången mot nettonollutsläpp. Framtida studier kan ytterligare berika denna förståelse genom att utforska effektiviteten i bankers hållbarhetsinitiativ, deras framsteg mot uppsatta hållbarhetsmål, och den utvecklande rollen för Grön IT i att driva hållbar bankverksamhet.

It is known that the decarbonization of our economy is crucial for our quest to mitigate climate change and build a sustainable society. Governments are reviewing strategies to eliminate, or at least minimize, the release of carbon emissions into the atmosphere. These efforts are not limited to national energy networks, but also extended to industry and other carbon-intensive sectors. In general, the Pulp & Paper industry is regarded as bio-based and relatively sustainable since most of its raw materials are recycled or come from biogenic sources. However, this is an energy-intensive industry, and even though bioenergy covers most of the energy needs at pulp plants, recycled paper mills do not count on the same resources and rely heavily on fossil fuels to power their operations. This study was performed to assess and compare different decarbonization pathways available for a recycled paper mill. For this, operational data was gathered to characterize the thermal and electric demands and assess locally available resources. Simultaneously, scientific literature was consulted to assemble a technology portfolio, from which the most suitable technologies were selected. Carbon capture and storage, electrification, and hydrogen were chosen to be tested, under different scenarios, using an energy modelling software. Finally, the combinations were evaluated and compared. It was found that under ideal conditions it is possible to achieve an emissions reduction of almost 100% via electrification and hydrogen-based options. However, this would represent a significant increase in the operating cost of the energy system and would depend on the development of the necessary infrastructure. The most promising alternative for this site was a combination of electrification and green electricity purchase agreements. However, further work is needed to improve the efficiency of the energy use and generation, to achieve a carbon-neutral operation without incurring elevated costs. / Det är känt att avkarboniseringen av vår ekonomi är avgörande för vår strävan att mildra klimatförändringarna och bygga ett hållbart samhälle. Regeringar ser över strategier för att eliminera, eller åtminstone minimera, utsläpp av koldioxid i atmosfären. Dessa ansträngningar är inte begränsade till nationella energinät, utan sträcker sig även till industrin och andra kolintensiva sektorer. Massa- och pappersindustrin är biobaserad och relativt hållbar eftersom de flesta av dess råvaror återvinns eller kommer från biogena källor. Detta är dock en energiintensiv industri, och även om bioenergin täcker det mesta av energibehovet vid massafabrikerna, räknar inte återvunnet pappersbruk med samma resurser som är starkt beroende av fossila bränslen för att driva sin verksamhet. Denna studie utfördes för att bedöma och jämföra olika avkolningsvägar tillgängliga för ett återvunnet pappersbruk. För detta samlades operativa data in för att karakterisera de termiska och elektriska kraven och bedöma lokalt tillgängliga resurser. Samtidigt konsulterades vetenskaplig litteratur för att sammanställa en teknologiportfölj, från vilken de mest lämpliga teknologierna valdes ut. Kolavskiljning och lagring, elektrifiering och väte valdes ut för att testas, under olika scenarier, med hjälp av en mjukvara för energimodellering. Slutligen utvärderades och jämfördes kombinationerna. Man, fann att det under ideala förhållanden är möjligt att uppnå en utsläppsminskning på nästan 100 % via elektrifiering och vätebaserade alternativ. Detta skulle dock innebära en betydande ökning av driftskostnaden för energisystemet och skulle bero på utvecklingen av den nödvändiga infrastrukturen. Det mest lovande alternativet för denna plats var en kombination av elektrifiering och köp av grön el. Det krävs dock ytterligare arbete för att effektivisera energianvändningen och energiproduktionen, för att uppnå en koldioxidneutral drift utan förhöjda kostnader.