Energy-saving transformation: the community is more green and livable

Source: China Construction News Network

The notice issued by the Ministry of Housing and Urban-Rural Development and other departments on the solid promotion of the renovation of old urban communities in 2023 proposes to focus on promoting the energy-saving transformation of existing buildings, and according to the characteristics of the climate zone, measures such as external wall roof thermal insulation transformation and replacement of external Windows can be selected. In practice, many places have included energy-saving renovation of existing buildings in the old residential area in the transformation "menu", in reducing energy consumption of external walls, doors and Windows, enhancing insulation performance, "low-carbon wisdom" transformation, etc., the concept of green energy conservation throughout the whole transformation process, the use of new materials and new technologies to reduce building energy consumption, reduce operating costs, improve living quality, so that the old residential area to achieve green energy-saving upgrading.

Put on cotton-padded outer walls

Some old residential areas have problems such as damaged building facades and indoor cold in winter and hot in summer, which not only affect the quality of life of residents, but also consume more energy.

"Before the energy-saving transformation, there are many cracks in the walls and balconies of our buildings. In winter, the temperature is often only 16 to 17 degrees Celsius." "Now that the walls and roof have all been rebuilt, my home will definitely be warmer this winter, which is a good thing for us elderly people," said Ms. Zhou, a resident of Jinzeyuan Community in Taiyuan, Shanxi Province.

According to reports, the transformation of Taiyuan City covers 6 urban areas, 652 residential areas, 2,337 buildings, with a total construction area of about 10.02 million square meters. In the renovation, Taiyuan City doubled the thickness of the outer wall insulation layer of the residential area, and set the insulation layer of the roof and basement roof to form a closed insulation system. After the renovation of the house, the indoor temperature can be increased by 3 to 5 degrees Celsius in winter and reduced by 2 to 3 degrees Celsius in summer, effectively solving the problems such as cold penetration of the original wall and rain leakage on the roof of the community.

Recently, with the completion of the transformation of Changsheng Garden community in Jianchao District, the largest energy-saving renovation project of the old community in Taiyuan was completed, bringing more than 180,000 residents a more comfortable and energy-saving living environment.

In the process of transformation, the construction side will make a model of the construction technology of the building exterior wall at the gate of the community to show the residents. "The external wall construction includes insulation layer, plastering layer, surface layer and other construction, and the construction materials and practices of each layer are publicized to residents, which can visually show the benefits of energy-saving transformation to residents." The relevant person in charge of the construction side said.

The wall accounts for about 25% to 40% of the energy consumption of the building enclosure system, and in order to achieve the preset energy saving standards, it is necessary to use thermal insulation panels with good thermal insulation performance.

Qilihe District of Lanzhou City, Gansu Province adopts a new thermal insulation module and adds the design of dovetail groove, which can be seamlessly installed compared with the traditional external wall thermal insulation board, increase the integrity of external wall thermal insulation, good thermal insulation performance, light weight, simple and convenient installation, and achieve the unity of cost reduction and energy saving. Laizhou City of Shandong Province requires the construction party to carry out the construction in accordance with the A-class insulation materials, after cleaning the empty drum and weathered part of the original exterior wall, knocking off the old tile that has been loosened and chipping wool, filling the gap with polymer cement mortar to find equal steps, and then spraying paint to brighten the external facade, so that the exterior wall is more beautiful and thermal insulation.

Door and window help energy saving

It is understood that in the four building envelope components of doors and Windows, walls, roofing and ground, the insulation performance of doors and Windows is the worst, which is one of the main factors affecting the indoor thermal environment quality and building energy conservation. As far as the current typical envelope components are concerned, the thermal energy consumption of doors and Windows is about 4 times that of the wall, 5 times that of the roof, and more than 20 times that of the ground, accounting for about 40% to 50% of the total energy consumption of the building envelope components. Therefore, in addition to wearing a layer of "thermal insulation clothing" to the external wall, the replacement and upgrading of doors and Windows is also an important content.

Remove old Windows; Clean the debris around the window; Install new Windows and fasten them with nails; Put foam glue, sealing paste and other sealing materials around the window to ensure the window firmness and airtightness; Install window screens... This is the scene of the replacement of the outside window of No. 6 drainage yard in Nani Community, Taiyuan City.

In the renovation, the plastic steel window with better thermal insulation and sound insulation effect is used as the outer window in Taiyuan City, and the glass is also changed from single layer to double layer hollow glass flat window. "Since the Windows were replaced, the house has warmed up a bit, by three or four degrees Celsius." Resident Mr. Liu said.

In addition, Baiyin District of Baiyin City, Gansu Province will also replace the Windows of the stairwell during the renovation. "In the past, the stairwell Windows were all single-layer glass and steel Windows. After the renovation, they will be replaced with aluminum alloy hollow double-layer Windows. The energy-saving and thermal insulation effect of the stairwell will help the majority of residents live a warm and comfortable winter." Relevant person in charge said.

In the energy-saving transformation of the unit door, the unit door that is badly damaged and does not have the reconstruction value is replaced with a unit door with thermal insulation performance. "The doors and Windows of the former corridor are all aging, and the winter air leaks, the summer is stuffy, and it is not safe." Ms. Li, a resident of Ningyayuan Community in Yinchuan City, Ningxia Hui Autonomous Region, is full of expectations for a bright new corridor after the transformation, "no longer need to be afraid of cold winter and hot summer in the corridor."

Community wisdom reduces carbon

In addition to energy-saving transformation methods such as external wall insulation, some cities have also introduced new concepts to transform the community to "low-carbon wisdom".

Entering the construction of a community Xinhua community in Wuhan, Hubei province, "green" elements such as solar photovoltaic panels, solar street lights, sports power generation fitness equipment, and intelligent waste classification and reduction management stations can be seen everywhere. It is understood that Xinhua Community is one of the first old residential areas in Wuhan to transform low-carbon pilot communities, through a large number of new materials and new technologies, into a more fashionable and environmentally friendly "low-carbon community".

"Wuhan is hot in summer, and the installation of rooftop distributed photovoltaic panels will reduce the temperature of the overall building by 5 to 7 degrees Celsius." At the same time, by collecting clean energy for storage, and then secondary distribution of energy, it can also provide continuous solar power for the public areas of the district." The relevant person in charge said that the community has also introduced social capital to invest in new energy vehicle charging stations (piles), residents' idle items and recyclable waste intelligent collection and transportation systems, and set up community public welfare carbon funds; Placing sports power generation equipment in pocket parks; Use the concept of co-creation to mobilize the masses to participate in building community shared gardens and roof gardens.

Wuhan Wuzhan Community Education Committee dormitory extended the concept of green environmental protection to the house during the renovation. In order to completely solve the "oil snot" generated by cooking, the community replaced and installed smoke-free environmental protection cooktops for residents. "The traditional way of direct exhaust of oil smoke is transformed into a way of purifying oil smoke separation, which not only reduces environmental pollution, but also makes the facade more beautiful and convenient to clean. Now cooking is more happy." Resident Ms. Feng said.