Actively promote the external thermal insulation technology

Experts recommend that bookmark0 actively promote the external thermal insulation technology of external wall Gu Tongzeng (Beijing Institute of Architectural Design, Beijing 100045) economic advantages, that the internal insulation technology should be phased out, external thermal insulation technology should be actively promoted.

1 Various shortcomings and problems of the external insulation technology of the external wall In recent years, the thermal insulation and energy saving technology has been greatly developed in China, and Beijing is particularly prominent. If the “Implementation Rules for Energy Saving” of Beijing Municipality was issued in 1988, the technology has so far been More than 10 years of history. Looking back over the course of more than 10 years, the cumulative area of ​​building energy-saving housing in Beijing has reached more than 40 million m2, ranking first in the country. The diversity of building energy-saving technologies is also second to none in the country, but most of them are internal thermal insulation technologies. It should be acknowledged that in the early stages of the development of China's energy-saving technologies, internal thermal insulation technology has played a role in promoting China's energy-saving work. Because of its simple construction, safe operation and low cost, it is widely accepted by design, construction and construction companies. However, in terms of scientific rationality, it is obviously a transitional and backward structural form compared with the external insulation and energy-efficient single wall. Through more than 10 years of engineering practice, its shortcomings and problems have been clearly exposed.

Thermal bridge "is not easy to solve problems, such as beams, structural columns and out of the concrete components, especially those caused by ribbed insulation board" thermal bridge "phenomenon, not only affect the interior appearance, but more serious is the "heat bridge" condensation Even water and mildew affect the use.

Affecting the construction progress, such as interior decoration, the installation steps of radiators, toilets, sanitary ware, and electrical lines installed on the inner side of the outer wall must be completed after the internal insulation process is completed.

G) Internal insulation structure is easy to cause cracking reasons, in addition to its own material properties, structural reasons, one of the main reasons is that the external wall is directly exposed to the atmosphere, due to temperature changes caused by the wall deformation caused by the stress, easy to cause The lower strength of the inner thermal insulation layer is cracked, which is particularly important in high-rise buildings and east-west strips.

To achieve the "Beijing implementation of energy-saving rules," the average external wall heat transfer coefficient requirements, such as the wall with the same thermal conductivity of the thermal insulation material, the internal and external protection experts recommend that the thickness of the thermal insulation layer is very different. According to experts' research, taking a 240-square-thick ordinary clay brick wall as an example, if the average heat transfer coefficient of the outer wall reaches 116WV (mK), the thickness of the polyphenyl board attached to the inner side of the outer wall is 80mm, and the average heat transfer coefficient of the outer wall is 115WV ( M2 * K), to achieve the "Details" requirements, but the premise is that the building shape factor should be as mentioned above, due to the difference between the insulation materials used in the internal and external thermal insulation structure, the internal insulation structure will inevitably increase the project cost, but also accounted for the use of area.

According to incomplete statistics, each tower in the tower-shaped high-rise buildings will lose about 1.3 to 1.5m2 of use area, which is equal to the developer's “cost to pay the area” of the second renovation to destroy the internal insulation structure. For the first time decoration, this policy is reasonable, but here is not to talk about it but the second decoration is a common phenomenon, even if the unit decoration once completed, the residents will also have the guise of renovation, internal insulation has been destroyed, has been common.Current construction team The quality is generally not high, and the untrained migrant workers in the field have no license to work. After the internal insulation process is completed, it is common for the subsequent process to destroy the internal insulation structure. Finally, cement mortar is often used as a repair.

In the engineering design, the outer surface of the external wall is inevitably suspended or fixed, such as radiators, air conditioners, curtain boxes, and pipe cards. The thicker the internal insulation material, the harder it is to install, and the greater the possibility of damage. All of the above shortcomings and problems indicate that the internal thermal insulation technology can no longer meet the needs of building energy conservation development and should be phased out.

2 The Scientific Rationality and Potential Economic Advantages of External Wall Insulation Technology In summary, it can be considered that the main problem of internal insulation technology is that the insulation form is irrational and unscientific, and it is a backward transitional insulation form. In the future, it will be replaced by more scientific and reasonable external insulation technology or other forms. Compared with internal insulation, the scientific rationality of the construction of external insulation technology is obvious.

21 Potential Economic Advantages Some developers said: "I also know that external insulation is reasonably advanced, that is, there is no money." Their traditional concept is to determine that internal insulation is cheaper than external insulation. This is a one-sided view. There are currently more than the internal insulation. The economical and reasonable form of external insulation is now considered to be a departure from these advanced technologies, and a comparison is made between the use of materials and the use of space between the two.As mentioned above, the internal and external insulation materials are more than double the external insulation. The material fee can save about 15 yuan/m2 (wall surface), and the net use area should be increased by 1.3m2~1.5/m2 in the external insulation than in the internal insulation (the internal insulation thickness is in the conservative 60mm). The total investment is 1300 yuan to 1,500 yuan. If the price of commercial housing is 5,000 yuan/m2, the external insulation can be increased by 6500 yuan to 7500 yuan per household without investment, for example, 65 meters per household. , it is equivalent to a net increase of 100 yuan to 115 yuan per square meter, such as the ratio of the building area to the wall area of ​​1:0.5, equivalent to the wall area of ​​50 yuan to 57.5 yuan/m2, and the total cost of materials and investment to save 65~725 Of course, installed in a traditional way Lower than the inner insulation board insulation efficiency, even so, the overall economic cost of internal and external insulation is at least equivalent to the latest technology such as the use of external insulation with insulation board with the main concrete wall once survived watering, then certainly more economical than in the insulation.

22 Scientific and rational construction of external insulation technology The external insulation structure completely eliminates or weakens the impact of various parts of the “thermal bridge.” According to relevant statistics, the additional heat loss of the bottom part along the external wall room “thermal bridge” accounts for approximately Of the total heat loss, 237%, about 21.7% of the intermediate storey along the external wall room, and about 243% of the top storey along the external wall room. It can be seen that the increase in heat loss due to the “thermal bridge” is considerable. According to the research of relevant experts, the heat transfer coefficient and the average heat transfer coefficient of the main part of the internal thermal insulation technology are different by a factor of 1.8 to 20, while the use of external thermal insulation technology has a small difference between them.

23 Increased comfort of the indoor environment As a result of the use of external insulation, the thermal stability of the inside of the wall also increases. When the temperature of the indoor air rises or falls, the inside of the wall can absorb or release more heat, which is beneficial to maintain The room temperature is stable, so that the indoor thermal environment is improved.

24 can effectively protect the main structure, extend the life of the building because the insulation layer is placed on the outside of the main structure, reducing the stress of the main structure due to temperature deformation and the ultraviolet and harmful substances in the atmosphere to the wall erosion, thus improving the main structure The durability.

25 Energy-saving effect can increase the effective space of the building Because of the comprehensive insulation on the outside of the wall, the gap between the “thermal bridge” and the wall is blocked, which greatly improves the insulation and airtightness of the building, which is not only conducive to saving heating in winter. Energy consumption is also conducive to heat insulation in summer and energy consumption in air conditioning.

As mentioned above, according to rough estimates, if the internal insulation thickness is 60mm, the tower-shaped high-rise residential can increase 1.3~15m2 per household. In fact, even if the use of polystyrene board 240mm brick wall is also 80mm thick. If the external wall uses 180~ 200mm concrete wall may exceed 100mm. This area may reach 1.7~1. 8ml The Beijing Municipal Committee and the Fourth Committee issued a document in October 1998: > It is stipulated that the development department should sell the house according to the area of ​​use. Although this policy is currently not fully implemented, it is only a matter of time. As China's market economy continues to mature, the buyer-centered buyer’s market will, in order to protect its own interests, measure its own purchased homes, expedient gains and losses, and choose favorable options. We believe that the vast majority of residents will never choose thick-skinned watermelons. The mindset of developers is certainly no exception.

26 Comprehensive construction speed is not slower than internal insulation As mentioned above, one of the disadvantages of internal insulation is that most of the internal processes after the completion of the main structure can only be completed after the internal insulation is completed, and the cross-operation will affect the construction period; while the external insulation can be used internally or externally. At the same time, the overall duration is not necessarily longer than the internal insulation. Such as the use of external insulation and wall casting technology, then the internal insulation will greatly shorten the construction period. From an overall and macro perspective, external insulation is undoubtedly a scientific and reasonable insulation technology. But in the specific design and selection system must also be cautious, such as: 1 due to insulation materials placed outside the outer wall, year-round weather experts and solar radiation test, so be sure to choose good weather resistance, low water absorption, temperature and humidity Deformed lightweight and highly efficient insulation materials, but from the current situation, some did not pass the formal appraisal of the quality of low-cost workshop-style products are also flooded the market, external insulation structure cracking is still very common. 2 The external thermal insulation technology not only requires the quality of the material itself, but also the corresponding supporting materials and construction process. If the form of the hanging is used, the corresponding anchoring site, bonding material, plastering mortar, and reinforcing glass fiber mesh cloth and other technologies Performance indicators should be made in accordance with regulations. 3 Should also keep up with the software, from the plate quality, design method, construction process to the acceptance criteria should be based on law, should not be isolated from the choice of a certain material or practice, but should be regarded as a system Therefore, when choosing the type of external insulation, not only is the choice of materials and practices, it is more important to see whether this system is comprehensive. perfect.

3 Conclusions External wall insulation is a backward transitional thermal insulation energy-saving technology and should be phased out.

Live external wall insulation is a scientific and reasonable insulation energy-saving technology, its comprehensive economic efficiency is not worse than the internal insulation, when using some advanced technology is even better than the internal insulation, exterior insulation technology should be actively promoted.

Live hardware and software supporting the implementation of external thermal insulation technology should be followed in a timely manner to achieve the following rules. There are laws available to ensure project quality. Technical economy and energy efficiency. □ National patent technology Double-track mobile firing clay, coal gangue, shale brick Energy-saving furnace technology promotion For your design, construction, commissioning, training One-stop service Double track kiln Suitable for firing clay, coal gangue, shale Hollow Bricks and Solid Bricks This technology was granted a national patent (patent 5) in 1997 and was included in the “Singer Jige IJ* Project” by the Hunan Science and Technology Commission. The double-track track kiln has seven advantages over other clay brick kilns: The investment is less, and the investment is 50% less than the tunnel kiln of the same scale, the second is less land occupation, the land saving is 80% more than the ordinary wheel kiln, the more advanced tunnel kiln can save 50% of the land, and the third is saving energy. In general, the furnace saves electricity by 40% compared to 600 kilograms of coal per 10,000 bricks, and the fourth is that the assembly line is not affected by the natural climate and is produced year-round.5 The product quality is high.Because the billet does not have natural drying, the number of bricks is less, so the appearance Low loss, long-term production of the kiln, the color difference of the upper and lower balance bricks in the kiln, especially the firing of hollow bricks, is better. Sixth, the production cost is low.

Each 10,000 bricks saves 600 kilograms of raw coal and 40% less electricity than traditional kilns. It has low labor intensity and a high degree of mechanization. It reduces handling wastage fees, saves labor and rain cover fees, and production is not subject to natural weather. Relatively prolonged production of time is greatly increased, thereby reducing fixed costs. Seventh, there is no environmental pollution. The majestic kiln is majestic and beautiful, producing clean, no environmental pollution, no safety hazards, easy production, and easy management.

The kiln is suitable for use in mountainous areas, plains, places with relatively tight land resources, long rainy seasons, and large, medium, and small-sized enterprises that need to be converted, and brick factories that need to be expanded. Welcome all the bosses to visit, inspect, and telephone consultation. Our factory will receive warm reception.

Contact Unit: Xintian County, Hunan Province New Wall Material Factory Address: Longquan Road, Xintian County, Hunan Province (Originally in Zhongwang Tile Factory)