Miljöbyggnad is a Swedish system for certifying building in regarding to energy, indoor climate and materials. Energy usage in built environment occupies more than a third of total energy consumption and greenhouse gas emissions in Sweden (SEA, 2008). Among fifteen indicators regulated by Miljöbyggnad, four indicators which consist of specific energy use, thermal climate winter, thermal climate summer and daylight have been analyzed in this report. There has two objectives for the project. The first objective is to make optimized approaches for the building according to baseline simulation model. And the second objective is to make assessment of the optimized model based on Miljöbyggnad environmental certification. As a conclusion, the implemented approaches helped to improve indoor thermal comfort and decrease demand of operational electricity for lighting. The four analyzed indicator of the optimized model have achieved GOLD level according to criteria regulated by Miljöbyggnad.

This thesis, based on a methodology borrowed from Science and Technologies Studies (STS), studies the implications of using energy modeling software for code compliance in the architectural design process. Specifically, the careful study of the development and use the of the software itself, including the assumptions and frameworks of its developers and users, is required to accurately examine the implications and practical effectiveness of using energy modeling to aid in reducing the environmental consequences of the built environment. I argue that the value in studying energy modeling software is not primarily to improve the scientific accuracy of the software. Rather, the value is to demonstrate how the assumptions used in the software’s calculation methodology can adversely influence the technological decisions made by building designers when using the software to demonstrate compliance with energy codes. To develop this hypothesis I have employed both historical and empirical methods. In my historical analysis, I find that the origins of modern building energy modeling software date back to the beginning of the air conditioning industry at the start of the 20th century. One consequence of this history is that assumptions built into the software measure the relative efficiency of building components under static and assumed average conditions, but not the dynamic rates of consumption caused by inhabitation. This, in-turn, prescribes the problem-at-hand of energy code compliance as primarily technical. However, as others have argued, dynamic social and circumstantial issues also influence energy consumption (Guy & Shove, 2000). Therefore as means to examine potential conflicts between the static and technical method of analysis employed by code compliance energy modeling software and the dynamic and circumstantial context in which buildings are designed, my empirical analysis is of a design process for a net-zero energy subdivision in Austin, Texas in which energy modeling was required and used extensively. The case study is designed to demonstrate how the problems-at-hand for each distinct group of stakeholders involved in the design process was varied and did not necessarily conform to the technical solution advocated by the energy modeling process. A primary conclusion of my analysis is that all mature technologies come to us with embedded assumptions that may subvert our intentions. A secondary conclusion is that the competing assumptions and problem definitions of building scientists and building designers tend to frustrate the goal of sustainable development. My hope in studying energy modeling, in relation to practice and code compliance, is to discover ways to better use the analytical power of energy modeling that is more directly responsive to the dynamic and contextual conditions of architectural production and real world resource consumption. / text

The building sector represents the largest energy consumer among the United States' end use sectors. As a result, the public and private sector will continue to place great emphasis on designing energy efficient buildings that minimize operating costs while maintaining a healthy environment for its occupants. Creating design-phase building energy models can facilitate the process of selecting life-cycle appropriate design strategies aimed at maximizing building energy efficiency. The primary objective of this research study is to gain greater insight into likely causes of variation between energy predictions derived from building energy models and building energy performance during post-occupancy. Identifying sources of error can be used to improve future modeling efforts that can potentially lead to greater accuracy and better decisions made during the building's design phase. My research approach is to develop a method for conducting retrospective analysis of building energy models in the areas that affect the building's predicted and actual energy consumption. This entails collecting pre-construction and post-occupancy related data from various entities that exhibit influence on the building's energy performance. The method is then applied to recently-constructed military dormitory buildings that utilized building energy modeling and now have actual, metered building energy consumption data. The study also examines how building occupancy impacts energy performance. The value of this work will provide additional insight to future building energy modeling efforts. / text

This research evaluates current home energy assessment tools and practices and investigates their applicability in terms of relevance supporting retrofit decision making in Southwest Virginia. Home energy assessments and audits are comprised of many different tools, strategies, and practices all with the same goal, to achieve accuracy in assessing performance as well as confidence in achieving energy savings from retrofit recommendations. Differing opinions, training, and standards in energy assessments have led to a reduced confidence and reliance on energy assessments, which can ultimately lead to poor retrofit decisions and undesired outcomes. This research undertook an investigation of current tools and practices as well as modeling studies to reveal insights into strengths and weaknesses, and to refine home energy assessments. The goal was to identify opportunities to increase confidence for stakeholders by analyzing energy assessments in terms of what strategies are most suitable to increase the accuracy of capturing different energy influence parameters, as well as to provide a basis for future research and development in this subject area. / Master of Science

Buildings are responsible for over a third of the energy consumption in the United States annually. This energy consumption contributes to some of the most pressing problems facing our society. Modeling of buildings and their systems is an integral part of most strategies for reduction of energy use in buildings. Modeling allows for informed building designs, optimization of systems, and greater market acceptance of new energy-saving technologies. This work addresses two particular modeling applications concerned with reduction of energy usage in buildings: convective heat transfer modeling in perimeter zones, and liquid desiccant dehumidification modeling. The first objective of this work is concerned with modeling convective transport in buildings and creation of inputs for energy modeling programs and passive pollutant removal calculations. This is accomplished through four investigations. In the first investigation, the influence of floor diffusers on convection heat transfer at perimeter zone windows in commercial buildings is measured. In the second, the impact of blinds on convection under a variety of circumstances is quantified. In the third, movement of air jets issuing from floor diffusers is predicted, and the effect of buoyancy on convective heat transfer at perimeter zone surfaces is analyzed. In the fourth investigation, convective mass transfer at indoor surfaces is investigated. Full scale experiments were conducted in support of these four investigations and semi-empirical correlations vii consistent with theory are given to predict jet movement and convective transport under a variety of circumstances. The second objective of this dissertation is concerned with modeling and analysis of liquid desiccant dehumidification systems and is pursued through three additional investigations. The first is concerned with modeling small-scale transport within the channels of a liquid desiccant absorber and regenerator. Physical and empirical models are developed which agree well with laboratory data. During the second investigation, a dynamic model of a liquid desiccant dehumidification system is developed and integrated into a full-building energy simulation. This is used to assess the potential applicability of the system in supermarkets in various climates. The models developed are used to optimize the system and develop a procedure to size components in the final investigation. / text

Accurate modeling of energy flows in buildings is necessary for optimization of mechanical systems, and architectural designs and components. One specific process which has been studied little is that of forced convection on the interior surfaces of window assemblies, which is present in the majority of newly constructed commercial buildings. To this end, energy flows associated with a specific Heating Ventilation and Air-Conditioning (HVAC) configuration- a floor register near a glass curtain wall with or without Venetian blinds- are analyzed experimentally and partially described with accepted theory. Natural convection at the same surface is analyzed as well, both to establish a baseline and to experimentally validate the experimental setup. A 60 cubic meter environmental chamber with precisely controlled interior conditions and electrical resistance heating panels is employed to study heat transfer at the interior surfaces of a building’s envelope. Convection heat transfer processes for various blind angles, HVAC regimes, surface temperatures, and window sizes are examined. Results show that convection at window and blind surfaces is highly dependent on blind angle, supply temperature and flow rate, moderately dependent on room-supply air temperature difference and HVAC regime, and weakly dependent on surface-supply air temperature difference. A simplified model of convection heat transfer in this particular situation is proposed for easy implementation in energy modeling software. / text

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this research is to analyze the overall energy consumption of an industrial compressed air system, and identify the impact of various energy saving of individual subsystem on the overall system. Two parameters are introduced for energy consumption evaluation and potential energy saving: energy efficiency (e) and process effectiveness (n). An analytical energy model for air compression of the overall system was created taking into consideration the modeling of individual sub-system components: air compressor, after-cooler, filter, dryer and receiver. The analytical energy model for each subsystem included energy consumption evolution using the theoretical thermodynamic approach. Furthermore, pressure loss models of individual components along with pipe friction loss were included in the system overall efficiency calculation. The efficiency analysis methods and effectiveness approach discussed in this study were used to optimize energy consumption and quantify energy savings. The method was tested through a case study on a plant of a die-casting manufacturing company. The experimental system efficiency was 76.2% vs. 89.3% theoretical efficiency. This showed model uncertainty at ~15%. The effectiveness of reducing the set pressure increases as the difference in pressure increase. The effectiveness of using outside air for compressors intake is close to the compressors work reduction percentage. However, it becomes more effective when the temperature difference increase. This is mainly due to extra heat loss. There is potential room of improvement of the various component using the efficiency and effectiveness methods. These components include compressor, intercooler and dryer. Temperature is a crucial parameter that determines the energy consumption applied by these components. If optimum temperature can be determined, plenty of energy savings will be realized.

Urban energy system planning can play a pivotal role in the transition of urban areas towards energy efficiency and carbon neutrality. With the building sector being one of the main components of the urban energy system, there is a great opportunity for improving energy efficiency in cities if the spatio-temporal patterns of energy use in the building sector are accurately identified. A bottom-up engineering energy model of buildings, known as urban building energy model (UBEM), is an analytical tool for modeling buildings on city-levels and evaluating scenarios for an energy-efficient built environment, not only on the building-level but also on the district and city-level. Methods for developing an UBEM vary, yet, the majority of existing models use the same approach to incorporating already established building energy simulation software into the main core of the model. Due to difficulties in accessing building-specific information on the one hand, and the computational cost of UBEMs on the other hand, simplified building modeling is the most common method to make the modeling procedure more efficient. This thesis contributes to the state-of-the-art and advancement of the field of urban building energy modeling by analyzing the capabilities of conventional building simulation tools to handle an UBEM and suggesting modeling guidelines on the zoning configuration and levels of detail of the building models. According to the results from this thesis, it is concluded that with 16% relative difference from the annual measurements, EnergyPlus is the most suitable software that can handle large-scale building energy models efficiently. The results also show that on the individual building-level, a simplified single-zone model results in 6% mean absolute percentage deviation (MAPD) from a detailed multi-zone model. This thesis proposes that on the aggregated levels, simplified building models could contribute to the development of a fast but still accurate UBEM.

Building energy usage can be derived and controlled by performing building energy modeling. BEM can be performed using numerous software tools such as DesignBuilder, OpenStudio, EnergyPlus etc. These modeling tools can be sorted into three different modeling categories: Black-box, Gray-box and White-box. It is important for a modeler to be able to quickly select the proper tool from the proper category to meet the need of the project. To validate the method of categorizing tools, the three models generated using tools from each category and the modeling outputs required were compared. Each model was designed to estimate the amount of heat transfer through building envelope elements. All the modeling tools were able to generate the required output, therefore, the method for selecting the most effective tool will be based on the output requirements and the time it takes to build the model, time it takes to generate the output and interpret the output.

L’objectif de cette thèse est d’analyser l’apport des énergies renouvelables à la transitionénergétique dans les pays en développement (PED). L’apport des énergies renouvelables à latransition énergétique dans les pays en développement se justifie à deux niveaux. Dans unpremier temps il vise à étudier les conditions, moyens et conséquences de la modification desstructures de production énergétique existantes basées sur les technologies fossiles vers cellesintégrant les technologies propres qui sont plus respectueuses de la qualité de l’environnement.Dans un second temps, l’analyse de la transition énergétique propose une architectureinstitutionnelle, technologique, sociologique, réglementaire et managériale favorisant laconvergence vers un système socio-technique soutenable à travers la diffusion et l’adoption destechnologies renouvelables. Partant des approches existantes, l’idée fondatrice de cette thèse estd’insister sur la nécessité d’une mise en place d’une approche mixte de transition énergétiquedans les pays en développement en combinant une approche décentralisée (permettant de prendreen compte les caractéristiques spatiales des zones rurales enclavées) et centralisées (permettantd’insérer les PED dans un paradigme énergétique soutenable). A partir de cette orientation, nous!6proposons une approche interdisciplinaire empiriquement basée sur l’Afrique du Sud et leSénégal afin d’analyser l’apport des énergies renouvelables à la transition énergétique. Les outilsméthodologiques ont combiné la modélisation du type bottom-up et les techniques d’optimisationà travers les algorithmes de programmation linéaire. / The objective of this doctorate thesis is to investigate the contribution of renewable technologiesto energy transition in developing nations. In the theoretical framework such a contribution couldbe justified in two points. First, it analyses conditions, means and consequences of a modificationof a fuel-based energy production scheme to a new structure based on a more sustainableorientedpathway. Second, the analysis of energy transition provides institutional, technological,sociological and managerial frameworks strengthening the convergence toward a sustainableoriented energy paradigm through a diffusion and adoption of renewable technologies. From theexisting approaches, the core of this thesis is to assume a requirement to consider a mixedapproach of energy transition in developing nations through a combination of both decentralizedand centralized options. The decentralized energy transition approach allows an insertion ofspatial and geographical characteristics of remote locations in developing nations while thecentralized approach strengthens an inclusion of developing nations in a sustainable energyparadigm. From this orientation, we propose an interdisciplinary methodology, empirically basedon South Africa and Senegal in order to investigate the possible contribution of renewabletechnologies to energy transition. To investigate these questions, we combine a bottom-up energymodeling approach with optimization techniques through a linear programming algorithm.