The rapid exhaustion of the finite reserves of fossil-fuels adds to the woes on all walks of the society, and especially on the policy-makers, scientists and engineers to devise means to mitigate the consequences. Reducing energy demand and grid-dependency by decentralized energy production can help improve energy security of a nation. A holistic approach to achieve these goals in the building sector could be through a shift towards fostering near zero-energy communities. This project is an initiative taken by the residents in Van Maanenblok, an urban residential block constructed in early 1930’s and situated at the heart of North-Rotterdam, to try to achieve self-sustainability in terms of energy consumption of the block through renovation. The objective of this study is to analyze the energy consumption of the block over the past three years and using the ‘Trias Energetica’ approach, investigate the extent to which self-sustainability is possible. This study also includes an overview on financial feasibility of this initiative together with identification of innovation opportunities. Passive energy reduction measures such as insulation, LED lighting-retrofits have been explored. Active renewable energy systems (RES) like solar photovoltaic (PV) systems, micro-windmills were designed and sized. Also, energy potential from Organic Fraction of Municipal Solid Waste (OFMSW) from within the block, and use ground-source heat pump to meet thermal energy has been investigated. The aforementioned technologies have been compared over certain financial parameters like net present value (NPV), payback period (PBP), and levelised cost of energy (LCOE) based on installation costs obtained from actual figures quoted by the installers and also general indicative market figures. Results of the study indicate that nearly 54% of present gas demand and 9% of electricity demand can be reduced by passive energy reduction measures alone. It would be possible to meet 42% and 54% of reduced electricity and gas demand respectively from RES. User-behaviour plays an important role in energy consumption and social factor largely determines the metamorphosis of projects with such complex setup. Renovation projects towards near zero energy buildings opens up several innovative opportunities and extended benefits to various actors, however stimulus from government is needed on financial and technical front in order to realize such ambitious initiatives.

Samtidigt som kraven på energieffektivitet inom byggbranschen blir allt hårdare har klimatskalets utformning stor betydelse. Författarens uppgift är att utreda åt Sigma Civil AB hur ett verktyg som beräknar U-värden utformas samt att med hjälp av den göra en jämförande studie på yttertak och ytterväggar, med avseende på klimatskalets påfrestningar.   Andra delar som ingår i klimatskalet är grundkonstruktioner men eftersom det är ett arbete som omfattar 10 veckor avgränsas arbetet till yttertak och ytterväggar. För att arbetet skulle kunna utföras på ett bra sätt som möjligt har författaren genom litteraturstudier i form av böcker, internetbaserade sidor och olika rapporter tagit del av information som hjälpt både vid utförande av beräkningsverktyget men också vid jämförelsen av byggdelar.   Resultatet för den här studien visade att koljerntekniken på grund av sin täta struktur fungerar bäst av de takkonstruktioner som jämfördes i studien. I den analys som gjordes för väggkonstruktioner var det en yttervägg med PIR-isolering som klarade sig bäst. En av de slutsatser som jag drar av studien är att bättre isoleringsmaterial krävs för att klara framtidens krav på klimatskalet. Det andra som är viktigt att ta med sig från studien är att byggbranschen bör vara öppen för nya tekniker, som till exempel koljerntekniken och PIR-isoleringen. / While requirements increasingly become harder in the construction industry that it will be built energy efficient, buildings envelope design plays a very large part. My task is to investigate for Sigma Civil AB how a tool that calculates the U-value is formed as well as using it to make a comparative study on the roof and exterior wall, with respect for the building envelope external influences.   Another part of the building envelope is the basic designs, but because it is a work where is only 10 weeks I need to delimit to the roof and exterior walls. In order that the work could be carried out in the best possible way I did literature study in form of books, internet based pages and various reports to receive information that helped me both when I was performing the calculation tool but also doing the comparison of the building parts.   The result of this study showed that the koljern-technique because of its dense structure works best as a roof, compared to the other roofs in the study. In the analysis made for wall constructions, it was an exterior wall with PIR-insulation that worked best. One of the conclusions that I draw from this study is that better insulation needs to meet future requirements for the building envelope. The other thing that is important to take from the study is that the construction industry should be open to new technologies, such as the koljern-technique and PIR-insulation.

Purpose: Production and utilization of buildings contributes immensely to global carbon dioxide emissions. The construction sector today accounts for over a third of global energy use will increase as the world population increases. According to the EU Directive from 2010, all new buildings in EU member countries as of December 31, 2020 are to be classified as near-zero energy buildings (NZEB). The goal is to investigate the various energy-affecting measures of the involved architects, structural engineers and planners that can improve the energy performance of a kindergarten to be closer to near-zero and identify obstacles that make it more difficult to achieve NZEB. Method: The investigation strategies for the project are qualitative methods in the form of semi-structured interviews with architects, planners and ventilation engineers for six different kindergartens. The interviews were conducted by telephone in which the questions were sent in advance to those interviewed. Mail interviews were conducted early on which resulted in either short answers or not answers at all. The energy performance documents of the different kindergartens were analyzed to get information about the different energy performances. Findings: The result does not contain a solution as to what the near-zero energy definition is or how to define it, but is more like guidance concerning what factors you can influence to get closer to near-zero energy for a kindergarten. Recurring problems surfacing in the interviews is that not all the involved roles have been able to influence predetermined choices of shape and space that, among other things, contribute to a limited space for services that planners are having difficulty influencing afterwards. Implications: The result helps contribute to making sure buildings are built in a more energy-efficient way and by such reducing the construction sector's share of the global energy consumption. The building's energy efficiency may not contribute to poor indoor climate in such a way that it affects children's health in a negative manner. This results in a need for careful planning where all parties can contribute with their best energy efficiency solutions without being too limited by the architectural constraints of shape and space. Alternatively, better communication between planners and architects in the earlier stages. Good planning contributes to a better result. Limitations: The result is based on Swedish kindergartens in a Nordic climate and should not be applied in countries without a Nordic climate. The result is not only applicable to kindergartens but is largely applicable to most similar buildings. Contact with more architects, constructional engineers, planners and more kindergartens would have given a better result.

The European Parliament Buildings Directive (EPBD) obliges Sweden to develop plans to enhance the amount of NZEB. Define what NZEB for them exactly constitutes - technical definitions and system boundaries for energy performance calculations. The National Board of Housing, Building and Planning in Sweden has received an assignment from the Swedish government to propose the definition and quantitative approach on energy requirements for NZEB. NBHBP suggest the system boundary should be the delivered (bought) energy. The delivered energy divide into two different energy form. The set system boundary to calculate the specific energy performance with the introduced weighted factor. Makes it possible to compensate the specific energy performance by using renewable energy generators on site. The risk is inefficient buildings can use renewable energy technologies on site to compensate the delivered energy to achieve the 80 kWh/m2, year (the proposed energy requirements for NZEB). This results to high energy cost along with large investments in renewable technologies on site, or the need to add fossil fuels to make up the high-energy demand. The both reference houses Circuitus and Bright Living are NZEB, per the Swedish definition proposal of NZEB from NBHBP. The most significant difference is Circuitus has better heat exchanger and building envelope than Bright Living.

<p>Research on net-zero energy buildings (NZEBs) has been largely centered around improving building energy performance, while little attention has been given to indoor air quality. A critically important class of indoor air pollutants are nanoaerosols – airborne particulate matter smaller than 100 nm in size. Nanoaerosols penetrate deep into the human respiratory system and are associated with deleterious toxicological and human health outcomes. An important step towards improving indoor air quality in NZEBs is understanding how occupants, their activities, and building systems affect the emissions and fate of nanoaerosols. New developments in smart energy monitoring systems and smart thermostats offer a unique opportunity to track occupant activity patterns and the operational status of residential HVAC systems. In this study, we conducted a one-month field campaign in an occupied residential NZEB, the Purdue ReNEWW House, to explore how energy use profiles and smart thermostat data can be used to characterize indoor nanoaerosol dynamics. A Scanning Mobility Particle Sizer and Optical Particle Sizer were used to measure indoor aerosol concentrations and size distributions from 10 to 10,000 nm. AC current sensors were used to monitor electricity consumption of kitchen appliances (cooktop, oven, toaster, microwave, kitchen hood), the air handling unit (AHU), and the energy recovery ventilator (ERV). Two Ecobee smart thermostats informed the fractional amount of supply airflow directed to the basement and main floor. The nanoaerosol concentrations and energy use profiles were integrated with an aerosol physics-based material balance model to quantify nanoaerosol source and loss processes. Cooking activities were found to dominate the emissions of indoor nanoaerosols, often elevating indoor nanoaerosol concentrations beyond 10⁴ cm^-3. The emission rates for different cooking appliances varied from 10¹¹ h^-1 to 10¹⁴ h^-1. Loss rates were found to be significantly different between AHU/ERV off and on conditions, with median loss rates of 1.43 h^-1 to 3.68 h^-1, respectively. Probability density functions of the source and loss rates for different scenarios will be used in Monte Carlo simulations to predict indoor nanoaerosol concentrations in NZEBs using only energy consumption and smart thermostat data.</p>

Construction and operation of commercial and residential buildings in the United States have been identified as the single largest sector of energy consumption and contributor to greenhouse gas emissions. Subsequently, buildings must be a primary target for reductions. From short-term incentives, to long-term milestones, building energy efficiency, specifically net zero energy buildings, have emerged as a significant and unprecedented objective for a variety of public and private organizations in the United States. Altering the practices of the building culture requires not only technological innovation, but also an understanding of how practitioners within the building culture see their role in transforming it. Consequently my research seeks to understand how building industry professionals comprehend their capacity to influence the cultural boundaries of their profession in order to account for and mitigate the impacts of energy and emissions in the built environment. Ultimately, this study is an investigation into the social construction of technological change. The AIA+2030 Professional Series offered by the Denver Chapter of the American Institute of Architects has served as the single case study for this investigation. By limiting local conditions to the Denver-based Series and defining advocates as the self-selected group of participants, I’ve narrowed this analysis to reflect a workable microcosm of practitioners who are committed to the investigation and integration of net zero energy design, construction, and building operation practices. In order to substantiate this empirical analysis, I employed a triangulated series of data collection and interpretation consisting of: participant observation, interviews, and a survey. Data analysis involved an iterative process of coding and categorizing the primary key words and themes that emerged throughout my investigation. Each of the perspectives offered during this investigation indicate that architects who are advocates of net zero energy building design perceive that consequential opportunities for fundamental change exist within the social and cultural facets of the building culture. Ultimately, by preferencing social and cultural activism over technological manipulation, these advocates have corroborated the notion that technological change is fundamentally rooted in social change. / text

In this dissertation, we leverage predictive and prescriptive analytics to develop decision support systems to promote the use of renewable energy in society. Since electricity from renewable energy sources is still relatively expensive, there are variety of financial incentive programs available in different regions. Our research focuses on financial incentive programs and tackles two main problem: 1) how to optimally design and control hybrid renewable energy systems for residential and commercial buildings given the capacity based and performance based incentives, and 2) how to develop a model-based system for policy makers for designing optimal financial incentive programs to promote investment in net zero energy (NZE) buildings. In order to customize optimal investment and operational plans for buildings, we developed a mixed integer program (MIP). The optimization model considers the load profile and specifications of the buildings, local weather data, technology specifications and pricing, electricity tariff, and most importantly, the available financial incentives to assess the financial viability of investment in renewable energy. It is shown how the MIP model can be used in developing customized incentive policy designs and controls for renewable energy system.

The aim of the diploma thesis is to prepare documentation for construction. The building is partially basement and in terms of building physics is designed as a building with almost zero energy consumption. For the purpose of the work is chosen multifunctional object, which consists of veterinary clinic and shop with pet supplies. The building land is located in the cadastral area of Brno-Královo Pole in a built-up area designated for mixed areas of trade and services on a relatively flat plot no. 4800/28 on Edisonova Street. The new building is located on the southeast side of the property, which is followed by parking from the northwest side. The purpose, appearance and volume of the building do not interfere in any way with the character of the territory. Veterinary clinic is partially basement with two floors. In the basement is a technical background for the whole multifunctional building. On the first floor is a waiting room with a reception and two examination rooms, an office and a changing room for employees. On the floor are specialized workplaces, X-ray, ultrasonographic, otoscopic, laboratory and operating room together with hospitalization for animals. The shop with pet supplies is designed as a single storey, consisting of a sale area with a warehouse and facilities for employees. The southeast facade is covered with expanded metal. The construction system of the building is wall-mounted, made of ceramic bricks for thin-layer mortar. Ceiling constructions are designed from large-area filigree panels. The roof is vegetational.

This research paper examines possible solutions for the problems that warm air heating is suffering in Nearly Zero Energy Buildings. These NZEBs are passive houses constructed to have high energy efficiency where the quantity of power used is equal to the power created annually, produced locally or in the surroundings by renewable energy sources. The problem is that this type of houses are facing problems when it comes to the heating system, where temperature of air in the ceiling is greater than on the floor, so temperature stratification happens and thermal comfort is not reached in the occupied zone. For this reason, this study is carried out and tries to find optimal solutions for warm air heating. To accomplish the investigation, an experimental study has been performed using water as the working fluid in a small-scale model. Here, paddles moved horizontally located in the center of the model at the inversion level have been used to simulate the effect that the diffuser does in the air when heating. Measurements with different paddles were made to analyze the importance of the size in the mixing and one of the paddles has been positioned on a side, next to the wall, to analyze the influence of an obstacle. It has been concluded that the area of the paddle does not have a great influence on the mixing rate, but the height of it. Also, the obstacle introduced when having the paddle next to the wall showed good results in the mixing rate. Finally, the potential energy of the water tank has not suffered any change at the surface but it has decreased at the bottom for all of the paddles, so it has been wound up that the area does not have influence on the change of potential energy. All in all, two main conclusions have been reached. On the one hand, the configuration of the air inlet diffuser significantly influences the rate of mixing. Specifically, a greater vertical size of the diffuser leads to a higher speed of mixing attainment. On the other hand, it is recommended to position the diffuser towards an obstacle, such as the adjacent wall, in order to induce turbulence. As a consequence, these findings can be investigated later in a real scale model using air as the working fluid. In this way, a solution for problems of warm air heating could be found.

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.