Two elements of the hottest energy-saving window w

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Two elements of energy-saving windows: window type and energy-saving glass

China's door and window industry is developing with the rapid development of economy. With the continuous advent of new materials, the door and window industry will develop to high-end, new-type, multi-function, multi variety and various real energy-saving types. Norman doors and windows seized this important opportunity in history to develop truly energy-saving doors and windows

correctly understand the "energy-saving window"

energy-saving window is the development direction of our industry. How to understand energy-saving window and how to calculate energy conservation must be understood from the three elements of thermodynamic heat conduction: that is, if there is no heat (entrepreneurial Service Department), mechanical heat loss (heat exchange) and heat convection, conduction and radiation. Convection is the circulating flow of hot and cold air flow between the gaps of doors and windows, which leads to the convection of gas and the heat exchange, and the circulating convection of hot and cold air leads to the loss of heat. The heat transfer guide is the heat transfer carried out by the molecular motion of the material itself, and the heat transfer is transferred from one surface of the object to another surface. Radiant heat transfer refers to the direct transmission of energy in the form of rays, namely infrared rays. No matter what material is used to make the window, if it can block and control the above three kinds of heat exchange most effectively, it can be called the best energy-saving window

analysis of two key elements of energy-saving window

in order to better achieve the blocking of three kinds of heat exchange and achieve a real energy-saving window, we should consider the following aspects:

window type is the leading element of energy-saving window

sliding window is not energy-saving window, casement window and fixed window are energy-saving windows. First of all, we should consider the structural design of the window, which plays a major role in energy conservation. For example, the sliding window slides back and forth on the slide rail under the window frame, with a large space on the top and a gap between the pulleys on the bottom. There is obvious convection exchange between the top and bottom of the window sash, and the convection of hot and cold air forms a large heat loss. Convection gives up the work of the world's top 500 researchers, and the heat loss is proportional to the space above and below the window sash. At this time, no heat insulation profile can be used as window frame to achieve energy-saving effect. It can be said that sliding windows made of aluminum alloy or plastic steel are not qualified to be called energy-saving windows

open the fuse window horizontally. Generally, good rubber sealing strips are used between the window sash and the window frame. After the window sash is closed, the sealing rubber strips are pressed tightly, and there is almost no gap, so it is difficult to form convection. The heat loss of this window type is mainly glass, window sash and window frame profile, heat conduction and radiation heat dissipation, which is much less than convective heat loss. If the heat conduction of the above glass and window frame profile can be well solved, the energy-saving effect of casement window is far more obvious than that of sliding window. Casement window can be called "energy-saving window"

fix the window, the window frame is embedded in the wall, and the glass is directly installed on the window frame. Now the glass and window frame have been sealed with sealant instead of adhesive strip, and the four sides in contact are sealed. If the sealant is sealed tightly, it is difficult for air to form convection through the sealant, and it is difficult to cause heat loss. The heat conduction of the fixed window glass and window frame is the main source of heat loss. Taking effective measures on the glass can greatly improve the energy-saving effect. Structurally speaking, the fixed window is the most energy-saving window type. For ventilation, a small upturned window is installed on the fixed window, or a small casement window is installed on one side of the fixed window, which is specially used for regular ventilation

at present, there are window types such as horizontal opening and hanging, various up and down sliding windows, and various types of outward opening and inward opening, but they all change within the three window types of push-pull, horizontal opening and fixed

glass is the second element of energy-saving windows

in addition to the structure of windows, the largest heat conduction and radiation area of windows is glass. The heat dissipation of glass mainly depends on heat conduction and heat radiation. Conduction is the transfer of heat from the inner surface of the glass to the surface of the glass window through the molecular movement of the glass. The size of heat conduction is related to the conduction velocity, the thickness of glass, the thermal conductivity of different glasses, as well as the performance of glasses with different properties, while the radiation is related to glasses with different properties

1。 The heat reflection coated glass

has better optical control performance, with a wavelength of 0.. 5mm sunlight has good reflection and absorption capacity, which can significantly reduce the transmission of solar radiation energy to the room, maintain a stable indoor temperature, and save energy

in general, heat reflective coated glass can meet the needs of general energy-saving windows, such as higher requirements, insulating glass, heat reflective coated insulating glass and low radiation coated glass, but they have their own characteristics and different uses

2。 Insulating glass

insulating glass not only has excellent lighting performance, but also has special advantages such as heat insulation, sound insulation, frost and dew prevention. Insulating glass has excellent heat insulation performance, and its heat insulation performance can be better than that of ordinary concrete walls under some conditions. The insulating capacity of insulating glass mainly comes from the air layer sealed between the two layers of glass. The thermal conductivity of this air is 0. 028w/mk, while the thermal conductivity of glass is 0. 77w/mk, except that the four sides of the sealed insulating glass are thermally conductive with sealant, other large-area glasses rely on the air layer to conduct heat and increase the thermal resistance. Therefore, the insulating effect of insulating glass can be significantly improved

3。 Low radiation coated glass

low radiation coated glass is also known as Low-E glass. According to the production method, it can be divided into "Low-E glass" and "offline Low-E glass". Low-E glass, that is, on the float glass production line, tin gas is usually sprayed directly onto the molten metal surface. With the cooling of the glass, the metal film becomes a part of the glass. Its characteristics are that it can be used directly in the air, can be tempered, hot bent, and can be preserved for a long time. Its disadvantage is that its thermal performance is relatively poor. Compared with the "U" value of Low-E glass produced by "off-line" sputtering method, the "U" value is generally used to express the thermal insulation performance of window glass. "U" value is directly related to the emissivity of glass. "The lower the" U "value is, the lower the heat transfer through the glass is, the better the heat transfer performance of window glass is

another method is to produce Low-E glass (also known as offline Low-E glass) by sputtering. The production method is to directly deposit metallic silver on the surface of the glass by sputtering. Its disadvantage is that the silver film is very fragile and easy to generate silver oxide layer. Therefore, it cannot be used like ordinary glass. It must be made into insulating glass, which cannot be stored and transported for a long time before being made into insulating glass

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