When considering the global population increase by another 2 billion by 2050 and with 70 % of the world’s population living in cities, there will be an unprecedented demand for energy across the planet. The opportunity for architects and concerned parties to create buildings which reduce energy consumption has never been more apparent. But can energy efficiency be achieved based on the architectural intent only? One of the key challenges for architects is working in any way that is inclusive to others so that energy performance can be achieved. Once they overcome this challenge, it’s possible to look at the needs to be achieved in terms of design and energy performance, and then endeavor to make it happen. Energy‐saving buildings are good attempts in this field, involving the importance of social, cultural and economic. The structural elements of the building (foundation, wall, roof, openings) are of special concern in this paper, with respect to climate.
Keywords: energy efficient, building structure, architectural design, global warming
Потребность в использовании энергии увеличилась во много раз как при эксплуатации зданий, так и в инфраструктуре.
Энергоэффективность зданий может быть достигнута путем использования изоляционных материалов, улучшения строительной техники и модификации методологии строительства. Для создания энергоэффективных и устойчивых объектов в будущем, необходимо снижать потребность зданий в энергии без ущерба для комфортности проживания и производимых услуг. Чтобы внедрить энергоэффективный проект в коммерческих, жилых и промышленных зданиях, нужно изменить их архитектуру, дизайн и планировку.
Наблюдение и эксперимент проводились для четырех существующих зданий и основывались на используемых строительных материалах, типе конструкции, архитектурных методах, а также учитывали непосредственное назначение объектов. В этой статье объясняются элементы дизайна для энергоэффективности.
Ключевые слова: энергоэффективность, структура здания, архитектурный дизайн, глобальное потепление
Introduction: We live in such busy times that facing a problem, we don’t stop to think whether someone may have already solved it before us. And so when we are asked to design a building which reduces energy loss to a minimum we quickly reach for a 19th century handbook, while the problem may had already been solved way back in the 10th century{1}.
It has taken us a while, but we have finally realized at the cost of the air we breathe that in recent decades, architecture has been far from adaptation to the environment in its urge for standardization. It is not possible to use the same type of building everywhere in the world and expect it to be efficient and sustainable, and yet that is precisely what we have been doing for the last 100 years.
Perhaps we should stop for a moment, look back at traditional architecture, and ask ourselves why no climate control devices were necessary back then. Or we could perhaps even name it bioclimatic architecture to make it look more attractive.
Buildings, as they are designed and used today, contribute to serious environmental problems because of excessive consumption of energy and other natural resources. The close connection between energy use in buildings and environmental damage is because energy intensive solutions aimed at constructing a building and meet its demands for heating, cooling, ventilation & lighting cause severe depletion of invaluable environmental resources. However, buildings can be designed to meet residents' need for heat and visual comfort at reduced energy and resources consumption. Energy efficiency in new constructions can be effected by adopting an integrated approach to building design. The primary steps in this approach would be to{2}:
- Incorporate passive solar techniques in a building design to minimize load on conventional systems (heating, cooling, ventilation and lighting). Passive systems provide heat and visual comfort by using natural energy sources and sinks, e. g. solar radiation, outside air, sky, wet surfaces, vegetation, internal gains etc. Energy flows in these systems are provided by natural means such as radiation, conduction, convection with minimal or no use of mechanical means. Passive solar systems thus, vary depending on the climate, e. g. in a cold climate an architects aim would be to design a building in such a way as to maximize solar gains, but in a hot climate the primary aim would be to reduce solar gains, maximize natural ventilation, and so on.
- Design energy-efficient lighting and HVAC (heating, ventilation and air-conditioning) systems. Once the passive solar architectural concepts are applied to the design, the load on conventional systems (HVAC and lighting) reduces. Further, energy conservation is possible by rational design of the artificial lighting and HVAC system using energy efficient equipment, controls and operation strategies.
- Use renewable energy systems (solar photovoltaic systems/solar water heating systems) to support a part of building load. The load on the earth’s nonrenewable resources can be alleviated by the expedient use of earth’s renewable resources i. e. solar energy. Using solar energy to meet electrical needs of a building can further reduce consumption of conventional forms of energy.
- Use low energy materials and methods of construction and reduce transportation energy. An architect should also aim at efficient structural design, reduce the use of high-energy building material (glass, steel etc.) and transportation energy, and use low-energy buildings materials.
Thus, in brief, an energy efficient building balances all aspects of energy use in a building: lighting, air conditioning and ventilation, by providing an optimized mix of passive solar design strategies, energy-efficient equipment and renewable sources of energy. The use of materials with low embodied energy also provides a major component in energy-efficient building design.
Design elements:
(a) landscaping
(b) the ratio of built area to open spaces
(c) location of water bodies
(d) orientation
(e) platform
(f) building envelope and fenestration.
However, in extreme climatic conditions, one cannot achieve comfortable indoor conditions by these design considerations only. There are certain proven and established concepts which, if applied to a design in such climatic conditions, may largely satisfy the heat comfort criteria. These are classified as advanced passive solar techniques. The two broad categories of advanced concepts are:
1. Passive heating concepts (direct gain system, indirect gain system, sunspaces, etc.), and
2. Passive cooling concepts (evaporative cooling, ventilation, wind tower, earth-air tunnel, etc.) {3}.
Landscaping: Landscaping is an important element in altering the microclimate of a place. Proper landscaping reduces direct sun from striking and heating up building surfaces. It prevents reflected light carrying heat into a building from the ground or other surfaces. Landscaping creates different airflow patterns and can be used to direct or divert the wind advantageously by causing a pressure difference. Additionally, the shade created by trees and the effect of grass and shrubs reduce air temperatures adjoining the building and provide evaporative cooling. Properly designed roof gardens help to reduce heat loads in a building.
Building shape / surface-to-volume ratio: The volume of space inside a building to be heated or cooled and its relationship with the area of the envelope enclosing the volume affects the thermal performance of the building. This parameter, known as the S/V (surface-to-volume) ratio, is determined by the building shape. For any given building volume, the more compact the shape, the less wasteful it is in gaining/losing heat. Hence, in hot, dry, regions and cold climates, buildings have compact shape with a low S/V ratio to reduce heat gain and losses respectively. The building shape also determines the airflow pattern around the building, directly affecting its ventilation. The depth of a building also determines the requirements for artificial lighting the more the depth, the higher the need for artificial lighting.
Location of water bodies: Water is a very good modifier of microclimate. It takes up a large amount of heat in evaporation and causes significant cooling especially in a hot and dry climate. On the other hand, in humid climates, water should be avoided as it facilitates to more humidity. Water has been used very effectively as a modifier of microclimate in the WALMI building complex at Bhopal {4}.
Orientation: Building orientation is a significant design consideration, mainly with regard to solar radiation and wind. In predominantly cold regions, buildings should be oriented to maximize solar gain; the opposite is advisable for hot regions. In regions where seasonal changes are very pronounced, both may be the case periodically. For a cold climate, an orientation slightly east of south is favored (especially 15° east of south), as this exposes the structure to more morning than afternoon sun and enables the house to begin to heat during the day.
Building envelope and fenestration: The building envelope and its components are key determinants of the amount of heat gain and loss, and wind that enters inside. The primary elements affecting the performance of the building envelope are
(a) Materials and construction techniques
(b) Roof
(c) Walls
(d) Fenestration and shading
(e) Finishing
Energy efficient buildings: environmental impact can be minimized with energy efficient buildings that reduce greenhouse gas emissions and are environmentally sound while selecting the materials and waste management. In addition, these energy efficient buildings contribute to a better indoor and outdoor air quality leading to healthy environment. Further, efficient buildings can improve the quality of life of millions of people because they provide better comfort and proper ventilation. Energy efficiency can expand the existing electricity resources further by providing better energy access, reliability and safety in remote areas.
Sustainable development offers us the triple benefits of social equity, environmental protection and economic progress today and the generations to come. Building efficiency is vital for sustainable development as it aligns economic, social and environmental objectives by increasing energy productivity, greening urbanization, water and materials efficiency, mitigating greenhouse gas emissions, and improving the building quality. Energy efficient buildings help in achieving sustainable development goals through the cooperation of industries and governments{5}. By adopting policies prioritizing life-cycle and performance metrics and engaging in more integrated planning processes, design and construction of buildings can contribute to national and urban sustainability goals.
Conclusions: Energy efficiency is the wave of the future. The world is quickly moving towards energy sustainability. At the same time, the mankind is trying to re-establish the connection it once had with nature. An energy efficient home is a personal step toward renewable energy, environmental protection, and sustainable living. Having such a home helps homeowners reduce their bills and provides an excellent investment. Furthermore, energy efficiency means healthier and more comfortable living in line with nature.
Building or upgrading to an energy efficient home requires an initial investment that is higher than the cost of a traditionally constructed building. However, there are government grants and incentives that can help to get you started and offset some of the cost. After living in your energy efficient home for a few years, your upfront investment will pay for itself.
References:
- Edwards, B., Sibley, M., Hakmi, M., Land, P.: Courtyard Housing. Past, Present and Future. Abingdon: Taylor & Francis, 2006
- Schramm, H.: Low Rise-High Density, Horizontale Verdichtungsformen im Wohnbau. Wien: Springer, 2005.
- www.extreme-weather-impacts.net/twi/ Wehage, P., Pahl-Weber, E.: Architectural Studies in: Pahl-Weber, E., Seelig, S., Ohlenburg, H.: The Shahre Javan Community Detailed Plan Planning for Climate Responsive and Sustainable Iranian Urban Quarter. Berlin: Young Cities Research Paper Series, Vol. 3, 2012.
- Roaf, S.; Crichton, D.; Nicol, F. Adapting Buildings and Cities for Climate Chance; Architectural Press: Oxford,UK, 2009.
