Modeling of Building Envelope's Thermal Properties by Applying Phase Change Materials

AbstractAll new buildings must be nearly zero-energy buildings (NZEB) by 2020, and all new buildings occupied and owned by public authorities must be NZEB after 2018. These targets are set in the European Member States according to the EU directive on the Energy Performance of Buildings [1]. It is a huge challenge is to achieve these goals in northern countries where traditional energy saving measures – insulation, window performance, heat recovery from ventilation systems - balance on the border of cost optimality. New solutions have to be implemented in the field of energy saving and storing.The biomimicry approach imitates processes found in nature to solve human problems that can provide conceptually new solutions. The example of northern mammals can serve as inspiration – fatty tissue functions as thermal insulator of the body, but phase change properties of the lipids are also used to store and release heat.Phase change materials (PCM) have received much attention as an alternative for energy saving and storing. The energy demand for heating the building and thus CO2 emissions can be reduced by the amount of latent heat stored in PCMs. Lately different concepts on PCM integration in the building envelope are emerging – built-in walls, ceilings, floors, as a thin layer or large storage tanks. In order to create new PCM integrated building components – a solar thermal façade system appropriate PCM has to be chosen. This paper reviews the selection of PCM in melting temperature range 21–22̊C

Profile of Hard-to-Reach Energy Consumers: Definitions, Needs and Barriers

According to the European Union, household energy consumption accounts for up to 30% of total energy consumption. Therefore, the household sector has great potential for reducing greenhouse gas emissions. The introduction of energy efficiency measures and the renovation of multi-apartment buildings are important solutions for reducing greenhouse gas emissions and achieving climate neutrality in Latvia. However, this potential is not being fully exploited because the renovation process in the multi-apartment building sector is extremely slow. One of the reasons for this is the lack of interest and willingness of residents to engage and agree on the implementation of energy efficiency measures in buildings. The study examines the main groups of energy consumers, their definitions, needs, as well as the most common obstacles and barriers that prevent energy consumers from fully engaging in the implementation of energy efficiency measures. To get an idea of the groups, publicly available information on the characteristics of hard-to-reach consumers was analysed, media content was analysed and interviews with energy experts were conducted. The results showed that the literature mentions different definitions, audience characteristics, barriers, and needs of hard-to-reach energy consumers. These definitions, barriers, and needs vary across countries and research contexts. There is a strong focus on overcoming barriers, but little research on the needs of the groups. Defining the audience accurately and studying the needs of the groups in depth are essential steps in developing and implementing appropriate policies for engaging hard-to-reach energy consumers. These findings highlight an important knowledge gap in this research field

Energy Efficiency Improvement Potential in Historical Brick Building

Energy efficiency in historical heritage buildings is viewed as a taboo because these buildings usually are law-protected and no energy efficiency measures that would change the appearance of building are allowed. In this paper we look at a potential of increasing energy efficiency level in historical buildings. Measurements to determine energy efficiency of a historical brick building have been done, which also give the possibility to determine the potential of energy efficiency measures in this building

Multiplayer game for decision-making in energy communities

Energy communities are widely studied from various perspectives, especially in the context of geopolitical events of recent years, when humanity is faced with the need for urgent solutions to promote climate change and alleviate the crisis of energy resources. Although citizens' interest in the use of renewable resources has gradually grown, energy policy support measures for more active participation of society in the implementation of energy efficiency measures are still being implemented with variable success, especially through mutual agreement. Serious games are a rapidly growing tool for awareness and collaboration on a single platform for gamers seeking solutions to energy resource optimization issues. The paper focuses on energy community versus energy use practices, trends, and intervention strategies in multifamily residential blocks, using serious gaming and direct user online feedback. This study uses a multi-player simulation tool to enable the modelling of scenarios for energy efficiency measures for apartment building block residents and energy community target goals for decision-making decisions. User experience and game mechanics were tested on a pre-selected group. The results indicate positive feedback, including a practical application for both energy community and professionals, and provide valuable recommendations for further research and improvement of the tool

Increasing Sustainability in Vocational Education System: Latvia Case Study

Promoting sustainability in educational systems is crucial for preserving resources and diminishing negative impacts on the environment. A key aspect of this is enhancing energy efficiency within educational institutions. By implementing energy-efficient building systems, advancing the use of renewable energy sources, and incorporating sustainable practices into the curriculum, educational institutions can decrease their environmental impact and conserve resources for future generations. Active participation from all stakeholders, including managers, teaching staff, and students, is essential for the success of these efforts. Providing students with a comprehensive education on sustainability equips them to apply this knowledge in their future professions, thus contributing to a more sustainable society. This research paper aims to explore ways to increase sustainability in Latvia's vocational education system, with a specific focus on reducing energy consumption in buildings and increasing the use of renewable energy sources. A study of 23 professional schools has been conducted to understand the current state of sustainability in the educational system, including data collection on energy consumption and surveying the schools on their current energy efficiency practices, renewable energy sources, and environmental policies. The energy efficiency and renewable energy production measures have been optimized for each school. A composite indicator has been developed to rank and compare schools based on their sustainability, promoting the use of energy-efficient and renewable energy sources within a limited budget. Results of the study show that by implementing mandatory and optional measures, the schools can significantly decrease primary energy consumption by 32% and greenhouse gas emissions by 33%

Deliberation Platform for Energy Transition Policies: How to Make Complex Things Simple

The energy transition from inefficient fossil-based to sustainable energy systems can face various lock-ins. There are no pathways that are free of stress. However, many routes are possible. A good understanding of the dynamic behavior of systems is crucial, and proper support tools are needed to assess the outcomes of every selected pathway. This study aims to develop an Internet-based interface tool for the national energy simulation model as a tool for a “hybrid forum”; study energy transition lock-ins in one of the Eastern European countries; and apply the interface tool to study different pathways to Latvia’s climate and energy goals. System dynamics are used to reach the goals of the study. A causal loop diagram is applied to study feedback loops and lock-ins, a stock-and-flow structure is used to build a simulation model, and a user interface tool is built on top of it. The results show that the developed interface tool is user-friendly and can be used as a discussion platform. The results from the case study reveal how the soft power of Russia can lock in the energy transition in Eastern European countries by creating policy choices with additive effects and what pathways towards energy transition can be used to lock-out

Eku energoefektivitates izpete. Ekonomiska un ekologiska optimizacija

Nowadays global warming and GHG emission are important concerns and an increasing attention is paid towards these issues. Kyoto protocol is one of the major documents where these questions are treated and it provides a thorough description of different cooperation mechanisms that countries may use for emission reduction. Latvia has recently signed this protocol, following its government has agreed to participate in AIJ projects and to take part at the emission trade. Reduction of energy consumption in buildings is one of the measures that implicate the attenuation of GHG emissions. Nevertheless, in Latvia there are no models, for analysing energy efficiency measures, which take into account the emission trading effect. Software tools made outside are not suitable, because their databases miss specific data for Latvian conditions. Furthermore, most of these softwares require very precise input data, which is not available for the existing buildings in Latvia. Reprogramming a database is a complicated operation and often requires input from its designer. Frequently these software tools are designed for a narrow circle of users and most of them are very complex and only specially trained customers are able to run them. One group of software tools are made for the purpose of one certain equipment manufacturer products. In this study the author has developed a quasi-static, one zone optimisation model "Maja". This model aids to determine the current energy consumption of dwelling, as well as it finds the optimal set of energy efficiency measures. The computer model consists of six modules. All these modules are interconnected to four calculation groups. The author has provided an optimisation method where two optimisation criteria have been employed: equivalent annual net costs and CO_2 emission reduction. In the course of this study, experimental data set of energy consumption for three heating seasons, building characteristics like geometry, location, building constructions, heating and hot water systems, inhabitants and climate for most widespread panel buildings built in Latvia between 1960 and 1990 has been analysed. The mathematical statistic methods, such as correlation and regression analyses, have been employed in order to define the regression equation for the current energy consumption of dwellings. In the scope of the study, author has specified the set of parameters that influence energy consumption of buildings. The test of importance in the heat balance of building of each of parameters has been carried out. Author has performed usage validity test of regression analysis including examination of normal division law for dependent variables, autocorrelation, multicolinearity and heteroscedascity. The investigations revealed that regression analysis has been used correctly. The results obtained during the examination of experimental data have shown that the computer model has adequately represented the energy consumption in buildings and it can be used to design energy efficiency measures. The computer model "Maja" can be used by several target audiences -homeowners, investors and state. Each of the groups can use different indicators and target functions depending on their particular interests. The model is approbated in dwellings in Kuldiga, Riga and Ventspils.Separate summaries in Latvian, EnglishAvailable from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi

Hygrothermal Performance Evaluation of Internally Insulated Historic Stone Building in a Cold Climate

In most cases, internal insulation is the only solution to improve the energy efficiency of historic buildings. However, it is one of the most challenging and complex energy efficiency measures due to changes in boundary conditions and hygrothermal behavior of the wall, particularly in cold climates. This study presents the long-term monitoring of the hygrothermal performance of an internally insulated historic stone wall building. The study aimed to assess the hygrothermal behavior of the dolomite wall if mineral wool insulation is applied internally on the north-east wall in the rooms with and without high internal moisture load. The measurements included temperature, relative humidity, water content, and heat flux. Monitoring results are compared with 1D hygrothermal simulations and a building energy consumption simulation. The in situ measurement results and hygrothermal assessment shows energy consumption decreased by 55% with relative humidity under the insulation staying belove 60% for most of the time, with short periods of increase over 80%. Energy consumption simulation shows an energy saving potential of up to 72% in the case of proper energy management