The use of energy in buildings is a complex problem, but it can be reduced and alleviated by making appropriate decisions. Therefore, architects face a major and responsible task of designing the built environment in such a way that its energy dependence will be reduced to a minimum, while at the same time being able to provide comfortable living conditions. Today, architects have many tools at their disposal, facilitating the design process and simultaneously ensuring proper assessment in the early stages of building design.
The purpose of this book is to present ongoing research from the universities involved in the project Creating the Network of Knowledge Labs for Sustainable and Resilient Environments (KLABS). This book attempts to highlight the problem of energy use in buildings and propose certain solutions. It consists of nine chapters, organised in three parts. The gathering of chapters into parts serves to identify the different themes that the designer needs to consider, namely energy resources, energy use and comfort, and energy efficiency.
Part 1, entitled “Sustainable and Resilient Energy Resources,” sets off by informing the reader about the basic principles of energy sources, production, and use. The chapters give an overview of all forms of energies and energy cycle from resources to end users and evaluate the resilience of renewable energy systems. This information is essential to realise that the building, as an energy consumer, is part of a greater system and the decisions can be made at different levels.
Part 2, entitled “Energy and Comfort in the Built Environment”, explain the relationship between energy use and thermal comfort in buildings and how it is predicted. Buildings consume energy to meet the users’ needs and to provide comfort. The appropriate selection of materials has a direct impact on the thermal properties of a building. Moreover, comfort is affected by parameters such as temperature, humidity, air movement, air quality, lighting, and noise. Understanding and calculating those conditions are valuable skills for the designers.
After the basics of energy use in buildings have been explained, Part 3, entitled “Energy Saving Strategies” aims to provide information and tools that enable an energy- and environmentally-conscious design. This part is the most extensive as it aims to cover different design aspects. Firstly, passive and active measures that the building design needs to include are explained. Those measures are seen from the perspective of heat flow and generation. The Passive House concept, which is explained in the second chapter of Part 3, is a design approach that successfully incorporates such measures, resulting in low energy use by the building. Other considerations that the following chapters cover are solar control, embodied energy and CO2 emissions, and finally economic evaluation. The energy saving strategies explained in this book, despite not being exhaustive, provide basic knowledge that the designer can use and build upon during the design of new buildings and existing building upgrades.
In the context of sustainability and resilience of the built environment, the reduction of energy demand is crucial. This book aims to provide a basic understanding of the energy flows in buildings and the subsequent impact for the building’s operation and its occupants. Most importantly, it covers the principles that need to be taken into account in energy efficient building design and demonstrates their effectiveness.
Designers are shaping the built environment and it is their task to make energy-conscious and informed decisions that result in comfortable and resilient buildings.
Energy Flows and Energy CycleFrom Resources to End Users
Energy resources are classified as renewable and non-renewable. Renewable energy sources include wind, solar, and hydro energy; while Non-renewable energies include nuclear fission materials and fossil fuels. Renewable and Non-renewable energies are regarded as primary energy sources that supply energy straight from raw fuels. The increasing price of oil constantly reminds us of the fact that all resources, except renewable ones, are depleting. Prices of energy will constantly increase, while energy reserves will weaken. It is well known that the efficient use of energy and resources is a fast and painless way of reducing energy costs and decreasing adverse impacts on the environment. There is huge pressure from the public and governments to act in a socially responsible way and to use resources efficiently. Special attention should be paid to energy use in buildings, keeping in mind that these man-made structures are one of the biggest energy consumers. The building sector uses 40% of all primary energy worldwide. Because of that, and the emphasis on efficient energy use there must be changes in this energy sector, by implementation of various energy efficiency strategies. This paper, basically divided in two parts, gives an overview about all forms of energies based on level of transformation, energy cycle from resources to end users, and basics of the energy balance of buildings.
Resilience of Renewable Energy Systems
Resilience is the ability of a system to resist unwanted influences and effects during its proper operation. The concept of resilience provides a new framework for how to “measure” the vitality/adaptability of systems and analysis systems, which faces many challenges (predictable and/or sudden changes). The resilience index of a defined energy system with the selection of the specific indicators reflects specific constraints, namely the change of individual indicators with other indicators being constant. The paper in the analysis of renewable energy systems (PV-solar and wind-based power plants) takes into consideration the following indicators: change of electricity costs, change of energy consumption of the system, change of the energy costs, change of electricity, change of concentration pollution gases for solar power plant, and change of wind power density, change of efficiency of wind power plant, change of frequency and change of electricity costs for wind power plant.
Material Aspect of Energy Performance and Thermal Comfort in Buildings
Modern design and construction strives to establish an appropriate relationship between three characteristic poles: man – the user, the building, and the environment. This chapter seeks to highlight this problem by considering the relevant characteristics of the building’s thermal envelope, i.e. the impact that the choice of materials has on the behaviour of the building as a whole. Today, we are intrigued by the behaviour of a building as a system, mostly through the prism of the amount of energy it consumes during its existence. On the one hand, this leads us to the need for adequate knowledge of the basic principles of building physics, and on the other, to the awareness of the relevant properties of the materials that we use in the construction process, in order to meet the comfort requirements of the user. Although this chapter emphasises the problem of meeting the thermal comfort requirements, in the example of the review and analysis of characteristic types of residential buildings in the Belgrade area, the scope of meeting the overall comfort requirements has been considered, as well as the interdependence that exists between different types of comfort (thermal, indoor air, sound, and light).
Embodied and Operational Primary Energy Content and CO2 EmissionsOptimising the Efficiency of the Building Envelope
Buildings are major energy consumers. The embodied energy and operational energy account for the largest share of the total energy use. Increased energy efficiency of the buildings, which results in reduced operational energy, entails an increase in embodied energy. For this reason, when improving the energy efficiency of buildings, the decisions and measures to be taken need to be properly balanced.
Embodied and operational energy and their environmental impact are evaluated with the environmental parameters PECn.r. (non-renewable primary energy content), GWP100 (global warming potential in 100 years), and AP (acidification potential). The energyenvironmental impact of the built-in energy is shown. The values of the above three environmental parameters, according to their thermal conductance coefficient λ, are presented for specific structural sections of the building envelope (walls, roof, floor to ground, windows). The most common construction sets for building envelope, composed of different materials - brick, wood, and aerated concrete, with added thermal insulation of synthetic, mineral, and natural origin, were analysed. The analysis of the building envelope structure also includes windows with different frames.
The advisability of thermal insulation improvement depends on the payback period. For the energy efficiency improvement measures of each individual construction set, the expected payback period is presented. The improvement of thermal insulation is achieved by additional thermal insulation, resulting in increased cost of investment.
Building Simulations and Modelling: Energy
The quest to achieve high standards in energy efficiency has resulted in the development of complex simulation tools that aim for a precise calculation of energy performance, thus supporting building design as well as the management process.
Common questions regarding the simulation of performance address several issues: during what stage is simulation being conducted (preliminary design, main design, dimensioning of the systems, certification), how complex is the procedure, what resources are needed (data and computational) etc.
In everyday practice we are confronted with a variety of available software options, each of which is advertised as the right choice for building energy performance simulation. With regard to the approach towards modelling, complexity, and simulation processes, we can distinguish several application levels, each having certain advantages and disadvantages. The starting point for an adequate simulation procedure relies on the available legislation and professional standards, calculation procedures, and computational logic. Depending on the desired outcome or goal of the process, an adequate simulation strategy must be applied. A comparison between the two most commonly used pieces of simulation software in Serbia, KnaufTerm2 and Ecotect, has been conducted, illustrating the differences in procedure and the results gained.
Environmental Design Principles for the Building Envelope and MorePassive and Active Measures
Given the need to reduce building sector related energy consumption and greenhouse gases (GHG), passive and sustainable buildings are a focal point. Simple methods and techniques, which use appropriate building design, material and systems selection, and reflect consideration of the local environmental elements, such as air and sun, provide thermal and visual comfort with less non-renewable energy sources. These techniques are referred to as environmental or bioclimatic design. There are two types of measures to be taken: passive and active. Passive principles exploit the design and properties of the building envelope to minimise or maximise the heat losses and heat gains respectively, to reduce the energy demand. In addition to passive, active measures such as heating systems and solar power technologies are used to produce and distribute the energy needed to achieve comfort of the occupants.
The present chapter aims at giving an overview of design principles that result in more comfortable and energy efficient buildings. Passive and active design principles are in line with the environmental design concepts. The environmental design principles can be beneficial to the building performance, whether the design ambition is to have a comfortable and functional building with reasonable energy demand or goes as far as achieving sustainable standards such as zero-energy or passive house.
The Passive House ConceptAn Energy, Environmental and Economic Optimum
The heating requirements of a passive house are up to 15 kWh/(m2∙a) of energy. Due to a good thermal and airtight envelope without thermal bridges, the building shows low transmission heat losses, while ventilation heat losses are reduced through a built-in system of controlled ventilation with heat recovery of the exhaust air. At their maximal load during peak heating season, heat losses do not exceed 10 W/m2 and can be compensated with hot air heating. In such buildings, conventional heating systems are no longer required. Increasingly, heat pumps are used as heat generators.
Such optimal results were made possible with considerable engineering knowledge and implementation experience, as the required rational concept can only be achieved by design optimisation, which must also be reflected in economic and environmental terms. Architectural and technological concepts to be included in the passive house design are presented. Using a model of a two-storey single-family house, five configurations are presented and evaluated with the parameters of energy efficiency (QNH/Au), primary energy consumption (PECn.r.), CO2 emissions (GWP100), cost (Cost) and living environment (LE).
Methods for Design of Static Solar Shading Devices
The existing condition of energy and environment requires that contemporary architecture pays particular attention to the exact parameters of energy optimisation, persistence, and sustainability of buildings and the built environment. One basic premise of sustainable development in architecture is the fulfilment of the requirement for luminous ambience – visual comfort in internal space, along with the optimisation of energy requirements. It is highlighted that it is important to integrate daylighting studies in the early design phases. Analyses and research have proved a connection between daily illuminance and heat losses/gains by emphasising the significance of the use of shading devices in the reduction of electrical energy consumption. In this way, the building envelope becomes unique and adaptable to climate, since it unifies and combines a myriad of specific patterns and methods of the location itself.
This work tackles the significance of the usage of daily illuminance in office buildings in Podgorica (capital of Montenegro) and daylight performance, in relation to an overview of the existing norms in this field. The second part of the paper will present basic formal typologies of external static shading devices and distribution of daily luminance and their use in office buildings, through the use of different software tools for the design and modelling of buildings. Conclusions are provided either as guidelines for the design of new projects, as general parameters, or as a verified method of adjustment of existing office buildings. The use of software has verified the respective research via simulations.
Economic Evaluation of the Energy Efficiency Improvement Projects
The process of adaptation of the buildings in architectural projects is codified by a set of energy efficiency regulations that are mandatory and which affect designers. To fulfil these requirements certain investments are necessary, which influence the economic performance of the project in construction phase, as well as in the long run over the building’s exploitation period. Therefore, an analysis of the economic effectiveness of the project is needed, which would also take into consideration the operation phase of the project, to include the whole life cycle. The methodology of the life cycle costs and savings analysis is presented in the following sections, which would be adjusted to the specific preconditions of the energy efficiency improvement projects, availability and possibility to gather relevant input data, as well as the perspective and understanding of architects as prospective analysis practitioners. The format of the proposed study is created to comprise several steps or phases, and their contents would be further elaborated. The methods that are applied include analytical procedure, comparisons, deduction and elaboration of the existing tools, and techniques and methods in the field of economic analyses in architecture and building construction. The resulting procedure allows for practical and theoretical implementation in actual projects. It is simple and straightforward to conduct, easy to understand, and open for expansion.
Copyright NoticeCopyright (c) 2018 Thaleia Konstantinou, Nataša Ćuković Ignjatović, Martina Zbašnik-Senegačnik
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