According to statistics, in developed countries, the energy consumption of air conditioning and heating accounts for 65% of building energy consumption
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The recent growth rate of energy consumption for heating, air conditioning and lighting in China has been significantly higher than that of energy production
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Therefore, reducing the energy consumption of cold, heat and lighting in buildings is an important part of reducing the total building energy consumption, which can be generally achieved from the following aspects
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1、 Facing the global energy and environmental problems, many new design concepts emerge at the historic moment, such as micro row building, low energy consumption building, zero energy building and green building
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In essence, they all require architects to start from the overall comprehensive design concept and adhere to the close cooperation with energy analysis experts, environmental experts, equipment engineers and structural engineers
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In building planning and design, according to the influence of a wide range of climatic conditions and the specific environmental and climatic characteristics of the building itself, attention should be paid to the use of natural environment (such as external air flow, rain, lake, greening, terrain, light, etc.) to create a good indoor microclimate, so as to minimize the dependence on building equipment
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Specific measures can be summarized as the following three aspects: 1
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Reasonable selection of building address and reasonable external environment design (the main methods are: arranging trees, vegetation, water surface, rockery and fence around the building); 2
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Reasonable design of building form (including the determination of overall building volume and building orientation) to improve the existing microclimate; 3
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Reasonable design of building form It is the key part to make full use of the outdoor microenvironment to improve the indoor microenvironment, mainly through the structural design of the building components and the reasonable separation design of the building internal space
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At the same time, the optimization design can be carried out with the help of relevant software, such as building shadow simulation, auxiliary design of building orientation and residential area road, greening, outdoor leisure space, and CFD software, such as PHOENICS, fluent, etc., to analyze whether the indoor and outdoor air flow is unobstructed
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2、 The design of building envelope components (roof, wall, foundation, door and window, shading facilities) has a fundamental impact on building energy consumption, environmental performance, indoor air quality and the visual and thermal comfort environment of users
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Generally, the cost of increasing the thermal performance of building envelope is only 3% ～ 6% of the total investment, but the energy saving can reach 20% ～ 40%
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By improving the thermal performance of building envelope, the outdoor heat can be reduced in summer, and the indoor heat loss can be reduced in winter, so that the building thermal environment can be improved, and the building cold and heat consumption can be reduced
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First of all, to improve the thermal performance of the components of the envelope, it is generally implemented by changing the thermal performance of the components
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There are different requirements for different types of buildings
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Different materials and technologies can be considered in each maintenance component
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Then, according to the local climate, the geographical location and orientation of the building, and guided by the calculation results of building energy consumption software, the optimal design method of envelope combination is selected
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Finally, the technical and economic feasibility of each component and combination of the envelope is evaluated to determine the technically feasible and economically reasonable envelope
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3、 In order to reduce the energy consumption of heating and air conditioning, high efficiency heating and air conditioning system should be combined with the above measures
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First of all, according to the characteristics and functions of the building, design high-efficiency HVAC equipment system, such as: heat pump system, energy storage system and district heating, cooling system
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Then, the energy management and monitoring system is used to monitor and control the indoor comfort, indoor air quality and energy consumption
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For example, European countries measure the temperature, humidity and sunshine intensity of the surrounding environment through sensors, and then predict the heating and air conditioning load based on the building dynamic model to control the operation of HVAC system
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In other home appliances and office equipment, we should try to use energy-saving certification products
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For example, the United States generally encourages the adoption of “Energy Star” products, while Australia implements minimum energy efficiency standards (MEPs) for energy intensive household appliances
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4、 In the process of improving the overall energy efficiency from primary energy to terminal energy used by building equipment system, energy loss is very large
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Therefore, we should evaluate the whole process (including mining, processing, transportation, storage, distribution and terminal utilization) to comprehensively reflect the energy utilization efficiency and the impact of energy on the environment
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Energy consumption equipment in buildings, such as air conditioning, water heater, washing machine, etc., should choose energy supply with high energy efficiency
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For example, as a fuel, natural gas is more energy efficient than electricity
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Adopting the second generation energy system can make full use of different grades of heat energy and maximize energy efficiency, such as CHP and CCHP
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The utilization of new energy plays an important role in energy conservation and environmental protection
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New energy usually refers to unconventional renewable energy, including solar energy, geothermal energy, wind energy, biomass energy, etc
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People have made extensive exploration on various ways of using solar energy, and gradually made clear the development direction, so that solar energy has been initially used
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For example: ① as an important project in the utilization of solar energy, solar thermal power generation technology is relatively mature
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The United States, Israel, Australia and other countries have invested in the construction of a number of experimental solar thermal power stations, which are expected to realize solar thermal power generation in the future (2) with the development of solar photovoltaic power generation, many photovoltaic power stations and “solar roof” demonstration projects have been built abroad, which will promote the rapid development of grid connected power generation system; (3) there are tens of thousands of photovoltaic water pumps in operation around the world; (4) the technology of solar water heater is relatively mature, with corresponding technical standards and specifications, but it still needs to be further improved (5) the passive solar building has been widely used because of its simple structure and low cost, and its design technology has been relatively mature, and there is a design manual for reference; (6) the solar absorption refrigeration technology appeared earlier, and has been applied in the field of large air conditioning; the solar absorption refrigeration is in the process of prototype development and experiment (7) solar drying and solar oven have been widely used
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But on the whole, the scale of solar energy utilization is not large, the technology is not perfect, and the commercialization degree is also low, which still needs to be further studied
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In the utilization of geothermal energy, on the one hand, high temperature geothermal energy can be used for power generation or directly used for heating and hot water supply; on the other hand, low temperature geothermal energy can be used with the help of ground source heat pump and underground air system
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Wind power generation is more suitable for windy coastal mountainous areas and high-rise buildings which are easy to cause strong wind
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There are successful engineering examples in Britain and Hong Kong, but in the field of construction, the more common form of wind energy utilization is natural ventilation
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