There is interest concerning the energy performance of buildings in the United States. Buildings, whether residential, commercial or institutional, generally underperform in terms of energy efficiency when compared to buildings that are constructed following sustainably and energy efficiency standards. A substantial percentage of energy loss in these buildings is associated with the thermal efficiency of its envelope (exterior walls, windows roof, floors and doors). The objective of this study will evaluate the results of three energy modeling techniques developed to investigate the energy transfer through the envelope of existing campus buildings. The techniques employed are solving the heat transfer calculations using spreadsheets, using a stand-alone modeling software (OpenStudio) and using an integrated building energy modeling software (eQuest) employed in Autodesk Revit. The first technique is somewhat different from the other two because it does not require a 3D representation of the building to be generated as the first step in the modeling process. It is the application of a mathematical methodology employing heat transfer algorithms entered into the spreadsheet’s cells to estimate the heat transfer through the building envelope. Data needed for this technique are weather data of the buildings location, surface area of the building envelope, and the overall heat transfer coefficient (U-value) of each component of the building envelope. The OpenStudio technique involves a 3D representation of the building. The building is drawn on a 3D modeling computer program called SketchupPro, which communicates directly to the OpenStudio energy modelling interface. The building operations as well as the building characteristics, such as the composition and type of the elements that made up the building envelop, the thermal zone, occupancy schedule and the space type was inputted in the OpenStudio engine. The OpenStudio engine runs the simulation and generates a detail result about the energy usage and energy transfer in the building. The third method that employs AutoCAD Revit software is a standalone technique that does not require an external software for sketching the building model. Revit the ability to draw the model as well as perform the energy analysis at the same time with the aid of inbuilt eQuest modeling engine. The model in Revit is generated with the right building envelope characteristics as the existing building and the weather file. The process is somewhat similar to the OpenStudio technique; the main difference is the level of detail and limitation provided by both the energy modeling engine (eQuest and EnergyPlus). At the end of the simulation, the building energy modeling using Autodesk Revit presents a detailed result of the energy usage and energy flow in the building. The underlying reason of the comparison of three techniques is to understand the simplest, most efficient, accurate method to quantify heat transfer through the building envelope. By the end of this study, the most efficient technique for investigating the building envelope will be expected to be the EnergyPlus technique because of the usage simplicity, ability to take in a lot of details required for simulation and the periodical software updates.

No description available.

One of the important reasons for the choice of the thesis topic are increasing requirements from the persons interested in low-energy, passive or even houses with almost zero energy consumption. During decreasing of the energy demand is within the framework of the idea of sustainable construction not only required to decrease the total energy demand of the buildings, search and solve the critical spots in the building jacketing, but also to use the secondary raw materials as full-value substitutions for commonly used products from the primary raw materials. The thesis tries to contribute to the possible usage of polymeric wastes in building industry. In an early stage of the thesis the main and partial targets together with the consecutive steps leading to their fulfilment were set. Selection of the suitable secondary raw materials, discussion with the specialists, initial sample mixing, finding their thermally – technical characteristics, press mould and fire kiln acquisition was carried out during the stage. The next phase is focused on the application of the products made from the secondary raw materials to the building envelope. The products are moulded according to the thermally – technical properties. Performed moulding approved that the products are fully functional and after reaching the required value of heat conductivity coefficient products eliminate imperfections of the solutions used at present. Strapping product for the threshold door joint is registered at Industrial Property Office of the Czech Republic and at European Patent Office at the same time. Recycled materials put into production represent possibilities how to decrease number of acquired virgin materials, need of primary energy and how to decrease risks connected to the waste disposal. Society is starting positively approaching to the products that are partially or fully produced from the secondary raw materials. Nevertheless, before the products from the recycled materials enter the peop

A study to optimize insulation thickness for stock-, industrial- and office-buildings for external walls and roof in an economical perspective has been conducted on behalf of DynaMate. DynaMate’s role is to maintain all Scania’s buildings. Analysis has also included other parts of the building envelope, such as windows, exterior doors and industrial doors. In this thesis, three different types of exterior wall constructions has been investigated, these are a sandwich design consisting of sheet metal and a another one consisting of concrete, as well as a wall of concrete with a coating of plasters. Furthermore, two types of roof structures have been studied, these are TRP-sheets and a concrete structure, both of which are externally isolated. For all types of building envelopes, different standard thicknesses of insulation have been used and the U-value of the windows has been varied. To calculate the energy needed for the different kinds of buildings, the program IDA Indoor Climate and Energy has been used.  Furthermore, a sensitivity analysis of the air tightness has been implemented for the building envelope. Based on the program results LCC (Life-cycle cost) calculations have been carried out for all combinations, thus be able to form an idea of ​​the combination and what kind of structure that is most economically tenable. A thermograph study was conducted in an existing warehouse at Scania. Observations show that the connection between the sandwich material of sheet metal and the foundation wall is flawed as this has a much lower thermal resistance compared to other parts of the building envelope. An alternative connection was developed which reduces the heat loss to one-fifth of the initial connection. An analysis regarding the companies approach to the vapour barrier in roof structures for industrial buildings has been investigated from a moisture standpoint. The analysis shows that without a functioning vapour barrier the moisture content in the construction increases over time, which leads to increased heating costs. The conclusion of this study shows that a reduction of insulation thickness for all types of studied buildings is more economically tenable than increasing the thickness. This is mainly due to the high cost of capital that the company uses for these investments. This means that any savings on cooling and heating costs very quickly is overthrown by the interest rate of the additional cost of the investment.

This is a study about how to improve the building envelope from a group of housing belonging to The Million Programme, a housing programme implanted in the Sweden around 70’s. Massive buildings made of concrete, which were constructed really fast because of the pressing time Schedule and were not developed as they should. This renovation study is explained with examples and drawings and it basically shows how to add thermal insulation on the most conflictive points of the building envelope. It is done in order to improve climatic conditions inside housing, trying to make thermal bridges disappear and reducing energy loss.

No description available.

Building management system (BMS) offers a wide range of measurements and historical data about the building but few types of researches use these data to analyze the building performance. This study aims to explore the indoor climate and building insulation by taking advantage of the BMS of the study case, which 767 sensors are installed in the room and wall structures and the signal data are available at the online web application. In addition, during the inspection, several error sensors and meters are detected are discussed as feedback for the system. It is concluded that the building management system is a good tool to study the building performance in different aspects and the measurements from the sensors are helpful but need validation by conducting a further field measurement in the building.

Sweden’s building sector contributes over one third of the country’s total energy consumption and over a fifth of its greenhouse gas emissions. To achieve the energy and climate goals that have been adopted by the Parliament in Sweden, work must be done within this sector to reduce its climate impact. The climate impact of a building is generated both during its service life, known as operational carbon, and during the production and processing of materials before and after construction, referred to as embodied carbon. Historically, operational carbon has made a larger contribution to a building’s total climate impact, resulting in operational carbon being the focus for reducing a building’s total climate impact. However, with improvements in the energy mix and buildings becoming more energy efficient, the operational carbon has been reduced, causing the embodied carbon to contribute more considerably to a building’s total climate impact. A building’s envelope protects the environment within the building from outdoor conditions, thus maintaining a stable indoor climate that is comfortable for the occupants. The amount and type of materials used in the building envelope impact the building’s heat losses and gains. Consequently, the material types and amounts used influence the operational carbon as well as the embodied carbon. By adding wall and/or roof insulation, or improving the windows’ U-value, the operational carbon is reduced, while the embodied carbon increases. With insulation and window changes made to improve the building envelope and reduce heat losses, this study aimed to investigate whether there is a point at which the reduction in operational carbon no longer outweighs the increase in embodied carbon, i.e., a break-even point. This aim was achieved by using a reference building based on which in a number of different cases of insulation and window options the operational carbon was estimated using IDA ICE and embodied carbon was estimated using One Click LCA. The results showed that none of the studied cases reached a break-even point. The cases in which reaching a break-even point was closest were those in which PIR wall insulation and glass wool roof insulation were used. Each of the studied insulation cases followed the expected trend of reduced change in operational carbon nearing the increase in embodied carbon. The continued increase in insulation would be impacted by cost related benefits and limitations. / Den svenska byggsektorn står för över en tredjedel av landets totala energianvändning och en femtedel av dess växthusutsläpp. För att nå de energi- och klimatmål som har antagits i Sverige behöver byggsektorn göra krafttag för att reducera dess klimatpåverkan. En byggnads klimatpåverkan uppstår både under drifttiden, driftskedets klimatpåverkan, och under utvinning och bearbetning av material innan och efter byggnation, vilket benämns som inbyggd klimatpåverkan.  Historiskt har driftskedet haft större klimatpåverkan på en byggnads totala klimatpåverkan, vilket har gjort att driftsfasen har hamnat i fokus för att minska en byggnads totala klimatpåverkan. Emellertid har en förbättrad energimix och mer energieffektiva byggnader medverkat till att driftskedets klimatpåverkan har minskat, med resultatet att den inbyggda klimatpåverkan nu har en större inverkan på en byggnads totala klimatpåverkan. En byggnads klimatskal skyddar inomhusmiljön mot omgivningens förhållanden, vilket möjliggör bibehållandet av ett inomhusklimat som är behagligt för människorna som vistas i byggnaden. Mängden och typen av material som används i en byggnads klimatskal påverkar värmeförluster och tillförsel i byggnaden. Därmed påverkar materialmänger och typer både driftskedets och den inbyggda klimatpåverkan. Genom att öka vägg- och/eller takisoleringen eller förbättra fönster U-värdet minskar driftskedets klimatpåverkan samtidigt som den inbyggda klimatpåverkan ökar. Med förbättringarna i isolering och fönster som har gjorts för att förbättra klimatskalet och minska värmeförluster, har denna studie syftat till att utreda om minskningen i driftskedets klimatpåverkan fortfarande överstiger ökningen i inbyggd klimatpåverkan. Detta syfte uppnåddes genom att använda en referensbyggnad för att uppskatta driftskedets klimatpåverkan i IDA ICE och den inbyggda klimatpåverkan i One Click LCA.  Resultaten visade att alla studerade fall fortfarande hade en högre minskning i driftskedets klimatpåverkan jämfört med ökningen i inbyggd klimatpåverkan. De fall där minskningen i driftskedets klimatpåverkan var närmast att vara likställd med ökningen i inbyggd klimatpåverkan var för väggisolering av PIR och för takisolering av glasull.

<p>In the United States, buildings are responsible for almost 40% of the country’s total energy consumption and 38% of the total greenhouse gas emissions. Researchers are constantly seeking sustainable and efficient energy generation solutions for buildings as society continues to cope with the intensifying energy crisis and environmental deterioration. Thermoelectric technology is one such solution that potentially can lead to significant energy recovery and conversion between waste or excess thermal energy and electrical energy. One promising application is integrating thermoelectric materials into the building envelope (TBE) for power generation and building heating and cooling without transporting energy among subsystems and refrigerant use. TBE can combine structural support and thermal storage with power generation and thermal-activated cooling and heating, thereby contributing to sustainable living and energy. </p> <p>TBE technology is still in its early development stages. This dissertation aimed to develop a fundamental understanding of the characteristics, behaviors, operation, and control of TBE systems as energy-efficient measures for thermal energy harvesting and thermal comfort regulation and to address the significant research gaps concerning high-conversion efficiency materials and optimal module configuration as well as system deployment related to real-world applications. Accordingly, this dissertation focused on the following three key objectives: (1) development and characterization of new thermoelectric composite materials; (2) identification of optimal designs and controls of TBE and established mathematical models for performance simulation; and (3) quantification of the energy-saving benefits of TBE. </p> <p>The following five aspects specifically were investigated:</p> <p>(1)<em> Material development and characterization</em>. New thermoelectric cement composites were developed with cement and various additives, material concentrations, and fabrication methods in the laboratory. Their thermoelectric properties (e.g., Seebeck coefficient, thermal conductivity, electrical conductivity, power factor, and the figure of merit) were measured simultaneously and characterized at 300–350 K.</p> <p>(2)<em> Module evaluation.</em> Commercially available thermoelectric modules (TEMs) were assessed using well-designed test apparatus in both the heat pumping and power generation modes. The test results validated the numerical model, which assisted with performance comparison and material selection between cement-based and commercial TEMs for the TBE prototype.</p> <p>(3)<em> Prototype assessment. </em>A convective TBE prototype and a radiant TBE prototype were designed, assembled, and evaluated in a pair of controlled testing chambers. The TBE’s surface temperature, thermal capacity, and COP were assessed under summer and winter conditions. </p> <p>(4)<em> Prototype modeling. </em>The first-principle-based numerical models of both the convective and radiant TBE prototypes were developed in Modelica. The modeling results indicated good agreement with the experimental data. The verified models were used to study the impacts of the design parameters and operating conditions on the heat pumping performance of TBE.</p> <p>(5)<em> System simulation. </em>A TBE building system model was established by integrating the TBE prototype model within a building’s heat balance model, considering the building construction, climate condition, power control, etc. Its seasonal performance under various climate conditions was studied to identify the potential optimal operation and energy savings. </p> <p>This dissertation confirmed several key findings in the areas of material development, system design and operation, and energy savings. The TBE achieved higher efficiency with a heat pump for heating than for cooling generally. The TBE heating system performed better than a conventional electric heater (efficiency assumed at 0.9). The measures that improved TBE heating efficiency were enhancing the material’s thermoelectric properties, optimizing the geometry and number of TEMs, and improving the boundary heat transfer of TEMs. </p> <p>This dissertation concluded that the TBE system is a promising alternative to conventional heating systems in buildings. Furthermore, the knowledge gained will strengthen the understanding of thermoelectrics in the building domain and guide further development in TBE, as well as facilitate the operation of net-zero energy and carbon-neutral buildings. </p>

The purpose of this work is to contribute to a process formaking buildings with good function and to avoid prematurefaults. The design, construction and installation of low-slopedroofs are important parts of creating a durable building. Mostof the leakages in low-sloped roofs occur where materials withdifferent thermomechanical properties are joined together. Withbetter knowledge about these joints, the expected service lifecould better be estimated. Common roofing materials onlow-sloped roofs are roof membranes. To avoid damages and to minimise energy consumption thedetection of air and water leaks is essential. It can bedifficult to localise a leak in e.g. a roof since water canflow far within the construction. Leakage detection can beapplied both as a quality assurance method after installationof low-sloped roofs and as field inspection methods. Theleakage detection can also be extended to terrace slabs and thewhole building envelope. To investigate the strength of jointsbetween sheet metaland roofing membranes, several small-scale tests and somelarge-scale tests were performed. The test methods weredeveloped to match the loads that can be expected on this kindof joints. A number of water leak-detection methods were evaluatedthrough application on test roofs. Some of the methods todetect leaks on low-sloped roofs can also be used to detect airleakage in other parts of the building envelope. To develop andevaluate air leak-detection procedures, selected methods wereused in two case studies. The circumstances regarding welding of the material jointswere found to have great impact on the strength. The roofshould be designed so no long-term strain will appear since acomparatively low stress may damage the joint over time. The performance of the leak-detection methods depends on theroofing material. All methods tested were an improvementcompared to visual inspections. Different recommendedapproaches for leakage detection and quality control is given.The case studies show that air leakage detection could beperformed with good accuracy. The potential difference methodcould without doubt be a tool for leakage localisation inwaterproofing layers both on roofs and in terrace slabs. <b>Keywords:</b>Roofing, roof membrane, durability,waterproofing, leakage, wind-load, non-destructive testing,NDT, BSL4, BSL3, air leakage, building envelope