کتاب An Introduction to Zero-Energy Building

Chapter 1. Housing and Energy
Introduction
Housing is a wide-ranging and complex issue for which there is no single definition. Housing is a physical place and, as a shelter, is a basic household need. The shelter provides some of the basic needs of the family or individual, such as food, rest, and protection from the weather. Housing, in addition to physical location, refers to the entire residential environment, including all the necessary services and facilities needed for family well-being and employment, education, and health projects (Pour Mohammadi, 2008: 3).
Housing plays a special role in meeting each of the basic human needs.
A) Shelter: According to Article 31 of the Constitution of the Islamic Republic of Iran, access to adequate housing is the right of every Iranian family, a suitable shelter that can protect people from the weather and provide residents with peace and health.
B) Economically: Housing today is a kind of investment and source of income and has an economic meaning.
C) Socially: In addition to the role of housing as a shelter, its main function is to provide favorable conditions for the realization of family activities, one of the positive consequences of which is the stability and solidarity of the family.
D) Job creation: Housing construction creates employment for a large group of people. Having a proper housing creates jobs for newcomers to the city and simple workers and, therefore, effectively contributes to economic development by increasing employment and income.
E) Mentally: Proper housing can be a place for peace, recuperation, and relaxation of nerves and thoughts in people, relieve mental and physical fatigue caused by daily work, or prepare them for activities mentally.
F) Communication advances: The development of communication technology in various fields will reduce the physical presence of humans in different parts of the city and, conversely, will increase their presence in housing. Unlike in the past, citizens spend most of their day and night in their homes, and their presence in their homes and surroundings is inevitable and far greater than in other parts of the city (ibid., pp. 7-5).
Energy Consumption in Housing
According to the latest statistics, the domestic and commercial sectors account for 40.7% of energy consumption in Iran.
Not only the domestic and commercial sectors have a high share in the country’s energy consumption, but also the relative energy consumption of buildings in Iran is higher than other countries and international standards. Reducing the energy consumption of buildings in Iran is necessary because the rapid growth of energy consumption in the last two decades has posed serious problems for the security of domestic energy supply.
The Need for Energy Efficiency
In addition to the economic burden, other factors necessitate energy efficiency, such as the indiscriminate use of fossil fuels that increase environmental pollution, high population growth, higher energy demand, limited energy sources, high energy consumption growth due to incorrect energy consumption pattern, lack of energy recycling system, worn-out industries and factories, national economy dependence on oil revenues, and rising greenhouse gases and acid rain.
Types of Energy
Energy has always been in the service of human beings in various forms and types from the beginning until now and has offered a lot of well-being and comfort to them in various forms such as muscle, mechanical, thermal, chemical, electrical, radiant and so on. One of the divisions of energy is based on energy carriers. Energy carriers refer to substances that store energy. These substances usually, after one or more deformations, become a final carrier with a final energy that reaches the consumer. Energy carriers can be divided into two groups: primary energy and secondary energy.
Primary energy: This type of energy is divided into three groups: non-renewable energy, renewable energy, and nuclear energy.
Renewable energy refers to energy from wind, water, solar, gas, geothermal energy and ocean energy, called natural or renewable energy.
The Principle of Conservation of Energy in Architecture
Every building must be designed and constructed to be in the least need for fossil fuels. The necessity of accepting this principle in the past has undoubtedly been undeniable given the way buildings are constructed. Such a principle has been forgotten in buildings perhaps only because of the great variety of new materials and technologies in modern times. During this period, buildings change the environment according to the needs of users by using different materials or different combinations of them. It is also worth mentioning the theory of the residential complex, which originates from providing shelter to survive the cold or creating a cool space for people to live. So, people constructed their buildings next to each other for many mutual benefits. The buildings constructed in response to the local climate to reduce dependence on fossil fuels carry unique experiences from today’s conventional apartments and, as a result, are seen as unfinished efforts to create green architecture. Many of these experiences are the result of individual work and effort. Therefore, they are not considered as sustainable principles in design and construction in today’s society (Khayatian, 2017).
Energy and the Environment
Humans gave a new color to life and provided for their basic needs by discovering fire and lighting it. In recent centuries, the level of welfare, technology and knowledge has improved with the discovery and exploitation of oil, gas and coal mines. Humans split the atom, owned nuclear energy, and met the growing need of industrial humans for energy. Over time, energy became so socially important that per capita energy consumption became a measure of social welfare and a turning point in assessing the level of well-being. These measures gradually determined the peak of progress, prosperity, and development, but suddenly the sound of alarm bells resounded from afar and became in tune with the voices of the saviors of nature and the environment day by day until the industrialized but nearsighted man saw the depth of the tragedy with his/her own eyes and touched it with all his/her being by protesting the human conscience (Ghodrati, 2016).

Energy Management
Although the sum of the energies within a system remains constant, some or all of it may converted from one form into another due to differences in energy quality. This conversion is never complete in nature. Therefore, the tools and machines used to convert energy always have an efficiency of less than 100%. This means that part of the available energy is always out of reach in the conversion of other types of energy and, eventually, becomes lower energy (heat).
– The use of building energy management systems (BEMSs);
– The use of home control systems;
– The use of occupancy sensing;
– The use of zoning systems;
– Systematic planning for the use of energy consuming appliances (for example, the lack of synchronization of the washing machine with similar appliances) during off-peak hours (Elhadidy, 2017).
Energy Consumption for Building Construction
Although in the definitions of zero-energy buildings (ZEBs), energy consumption for building construction has been neglected, institutions active in the field of energy rating of buildings have carefully studied it and considered a special score for it. The U.S. Green Building Council, called Leadership in Energy and Environmental Design (LEED), and the UK Building Research Establishment (BRE), the Environmental Assessment Method, have carefully examined the materials used in building construction. In general, energy consumption for construction has been studied in two parts: materials such as wood, and concrete and steel structures (Rogers 2019).
The building designer must evaluate the useful life of the materials to choose low-carbon and low -energy materials for the building. In assessing the useful life of materials, all environmental effects of materials are evaluated. This assessment includes carbon footprint, embodied energy coefficient (EEC), environmental and economic impacts of construction materials from the moment of extraction from mines, during production, transportation, use, storage, until recycling (re-use) (Khayatian, 2017).
Energy Consumption in Building Use
ZEB design principles to reduce energy consumption when using the building are divided into five main categories:
– Preventing energy losses: In designing ZEBs, preventing energy losses is the most important factor in energy consumption. Less energy losses mean the need for less heat or cold to be generated by air conditioners. Energy losses in buildings usually occur through the walls. Therefore, all thermal walls, or in other words, the border of ventilated spaces with non-ventilated spaces must be specified in plans and sections and must be completely and continuously insulated. In designing the thermal walls of buildings, attention should be paid to the removal of thermal bridges. Thermal bridges are the connections of building components (usually structures) from inside ventilated sections to outside this area. These connections cause energy loss through conduction if there is no insulation and proper thermal failure (Kazemi, 2017).
– Energy-efficient appliances: The use of equipment and appliances in residential houses is not limited to electronic equipment. Restrictions based on the number of residents have been applied to control the consumption of fresh water (Kunar, 2017).
– Maximum use of solar and wind energy: Maximum use of solar and wind energy for cooling and heating and the use of natural light for home lighting are inevitable because about 50% of the energy of ordinary homes is consumed by cooling and heating systems and the share of natural light in lighting is about 80% of the total energy consumption of homes. According to standards developed by LEED, 90% of the space occupied by homes should have natural light and scenery. In this regard, designers must pay special attention to the coefficient of natural light. The minimum amount of natural light for residential spaces is 2. Cooling and heating systems play an important role in reducing the thermal load of the building (Hajseghti, 2009).
– The use of renewable energy: ZEBs are referred to as buildings that provide the small amount of energy needed to create comfort for residents through renewable energy. Although renewable energy accounts for only 16.7% of the total energy produced in the world, the increasing use of it is quite significant (Khayatian, 2017).
– Intelligent energy monitoring and control systems in buildings: According to studies, one of the main reasons for high energy consumption is careless use of equipment. Therefore, it is very difficult for residents who are not accustomed to an optimal lifestyle to comply with the standards of ZEBs. Besides, residents do not have the time to monitor all parts of the house and also do not have much information about how the installation systems work. Therefore, the need to use an intelligent network to monitor and control all parts of the house at all hours of the day and night is clear. This network is called intelligent building management. The network is connected to one or more programmable logic controllers and monitors and controls the installation parts of the building. In this system, all previous systems are connected to a central control unit that is itself connected to the web server. Subsets of intelligent building network include intelligent lighting control system, intelligent weather forecasting system, and thermal zone air control system (Bogen Bilinton, 2017).
Quality of Building Materials to Optimize Energy Consumption
Selection of materials in cold areas: The main purpose in cold areas is to maintain heat inside the building, and the main factor in this case is the thermal resistance of the side walls of the building.
Selection of materials in hot areas: The most important factors determining the characteristics of building materials suitable for hot areas are the maximum daily air temperature and the range of its oscillation. Another important factor is the amount of sunlight absorbed by the wall, which depends on the orientation and color of the outer surface of the wall. The most important feature of building materials depends on their thermal resistance (R) and heat capacity (Q). Useful materials for keeping the building cool naturally include concrete walls with high heat capacity whose outer surface is covered with a layer of thermal insulation such as rock wool or plastic, which is itself covered with anti-moisture materials.
How to Use Energy in ZEBs
In ZEBs, the available energy is used to meet the needs of electricity, heating, or cooling. In each building, different micro-generation technologies may be used to supply heat and electricity by solar cells or wind turbines for electricity, fossil fuels, or solar heat collectors connected to a seasonal thermal energy storage (STES) to heat the open space. A STES can be used for cooling in summer by storing basement cold in winter. ZEBs are often connected to the electricity grid and transmit electricity to the grid to deal with the required fluctuations. However, when there is a surplus and not enough electricity is generated, it draws electricity to itself. Other buildings may be fully automated. Energy consumption is often more efficient when done in one area but on a combined scale, for example in a group of houses, group housing, area, village, etc. instead of individual houses. One energy gain of such regional energy consumption is the virtual elimination of transmission and distribution losses. The amount of these losses is about 2.7 to 7.4% of the energy transferred. Energy consumption in commercial and industrial applications should benefit from the mapping of each area. The production of goods under zero-emission fossil fuel energy requires the position of the earth’s central heat sources, the micro-driving force of water, solar, and wind to maintain this concept. Zero-energy neighborhoods, such as the creation of Bed ZED in the UK and those that are expanding rapidly in California and China, may use distributed generation (DG) schemes. This may in some cases include the heat of the area, cold water for the people, shared wind turbines, and so on.
There are schemes to use ZEB technologies to build entire cities that use zero or grid-independent energy.
Examples of ZEBs in the World
Ecotra House in Canada
The first house constructed in Canada was recognized as one of ZE top projects in 2007. The house was designed to provide an effective energy guide for Canadian homes and minimize negative impacts on the environment by combining energy efficient construction techniques and renewable energy systems.