With the development of economy and the improvement of people's living standards, people have higher requirements for the energy-saving level and comfort of existing buildings, and energy-saving renovation technology has been also constantly improving and progressing. ICESUN has proposed a convenient and economical energy-saving renovation measure, that is, replacing the original single-panel glass windows and insulating glass windows with vacuum glazing, which has significant energy-saving effect, improved comfort and extended life. With the development of economy and the improvement of people's living standards, people have higher requirements for the energy-saving level and comfort of existing buildings, and energy-saving renovation technology has been also constantly improving and progressing. ICESUN has proposed a convenient and economical energy-saving renovation measure, that is, replacing the original single-panel glass windows and insulating glass windows with vacuum glazing, which has significant energy-saving effect, improved comfort and extended life.
Overview
Green building has gradually become a well-known term. So what is green building? "Green building" refers to meeting GB/T 50378-2006 "Green Building Evaluation Standard", maximizing energy saving, land saving, water saving and material saving in the whole life cycle, protecting the environment and reducing pollution, providing people with healthy, Appropriate and efficient use of space, architecture in harmony with nature.
There are about 500 existing buildings in my country, of which the green building area is less than 0.1%. In recent years, the state has vigorously promoted green buildings and has issued a series of policies. Regarding new buildings, by 2020, green buildings will account for more than 30% of new buildings. Regarding the renovation of existing buildings, taking the northern heating area as an example, during the "Twelfth Five-Year Plan" period, the existing residential buildings in the northern heating area will have more than 4 heating metering and energy-saving renovation. It can be seen that the task is arduous and arduous.
As we all know, building energy consumption accounts for about 1/3 of the total social energy consumption, and the building protective structure is an important part of the building, and the building exterior window is an important part of the building envelope. Studies have shown that the area of external windows accounts for 25% to 35% of the area of the building envelope, and its energy loss accounts for about 50% of the energy loss of the entire building envelope. Therefore, improving the thermal insulation performance of the window, that is, reducing the heat transfer coefficient of the window, and selecting the shading coefficient of the window reasonably, are crucial for building energy conservation.
Vacuum Glazing Technology
Vacuum glass consists of two sheets of flat glass. The glass plates are separated by a series of brackets with a height of 0.2-0.4 mm. The two pieces of glass are sealed with glass solder around them. One of the pieces of glass has an air extraction hole for easy vacuuming. The two pieces of glass can be ordinary glass, or tempered glass or semi-tempered glass. To improve thermal performance, a piece of low-E film glass is usually used.
Energy-saving Effect Analysis of Vacuum Glazing Windows
The energy-saving effect of vacuum glazing windows in Harbin and Beijing areas is calculated by the cumulative evaluation method in winter and summer. The details are as follows:
The relative heat gain of doors and windows comes from the heat conduction caused by the solar thermal radiation and temperature difference transmitted by the windows. In summer, the more relative heat gain, the more air-conditioning load is needed in the room; in winter, the less relative heat gain, the more heating load the room needs. Therefore, the relative heat gain (RHG, Relative Heat Gain) of doors and windows can represent the "Relative Heat Consumption" (RHC, Relative Heat Consumption).
RHG=Σ(UApf (Tout –Tin )+(SHGC)Apf ET
U: heat transfer coefficient of the whole window, W/(M2•K);
SHGC: the solar radiation heat gain coefficient of the whole window, sum of solar radiation transmittance and indoor secondary heat transfer coefficient;
Apf: acreage of the whole window;
Tout: outdoor temperature;
Tin: indoor temperature;
ET: solar radiation intensity, kWh/m2
Calculations show that the energy saving of vacuum glazing has obvious advantages over other glazings. Due to the climatic characteristics of Beijing and Harbin, the thermal insulation advantage of vacuum glass can be brought into play, that is, the advantage of energy saving is reflected in heating in winter. With the reduction of the thermal insulation performance of glass windows, the energy-saving performance of vacuum glazing windows is becoming more and more obvious, that is to say, for the renovation of some old buildings, vacuum glazing has irreplaceable energy-saving advantages.
Performance Advantages of Vacuum Glazing
Low-E vacuum glazing replaces ordinary white glass and ordinary insulating glass, which greatly improves comfort, mainly in terms of sound insulation, heat insulation, anti-condensation and wind resistance, and at the same time, the life of the whole window is prolonged. Due to the existence of the vacuum layer, the sound insulation performance of vacuum glass is the best among all kinds of glass. The weighted sound insulation of glass is approximately 31 dB. The low frequency sound insulation performance of vacuum glass is very good, and it is very suitable for buildings facing streets, railways and airports. In order to achieve better sound insulation performance, vacuum glass can be further combined with insulating glass or laminated glass, and the composite can reach 42 dB. When it is used for the renovation of existing buildings, it is necessary to pay special attention to the selection of glass with good sound insulation performance, but also to choose better window profiles, especially to ensure good sealing, that is to say, the envelope structure system should be soundproofing. With vacuum layer, the gas heat transfer can be ignored. Besides, the high-performance Low-E glass is used to greatly suppress the radiation heat transfer and ensure that the heat transfer coefficient (U value) of the glass is as low as 0.4-0.6W/(m2·K) .