glass window is the medium of high building, house and the outside world. as the demand for glass is higher and higher, the ideal exterior window glass is not only transparent, it is necessary to reduce the heat exchange between indoor and outdoor as much as possible; in summer it blocks solar radiation heat, but in winter it can let the sun radiate heat in. however, such materials are not yet available, but are ideal materials.
zhejiang xixi glass co., ltd., as a professional fireproof glass manufacturer, supplies various kinds of safety grade glass, fireproof partition and insulating glass. laminated low-e hollow glass and double silver laminated low-e hollow glass is my company's main products.
low-e is the short of "low emissivity". the translation is the meaning of low radiation. the low-e glass is a magic film on the surface of the glass. how low is the radiation rate (emissivity) of this layer? the surface emissivity of ordinary white glass is 0.84, and the radiation rate can be reduced to less than 0.15 after coating the film.
kirchhoff's law in heat transfer tells us that the radiation ability of most objects is proportional to the absorptive capacity, and that the lower radiation rate means low absorption and high reflectivity. usually, the low-e film has a high reflection ratio for far infrared radiation (thermal radiation under indoor temperature), such as cold in winter, indoor heat, and indoor heat, which wants to run outward by radiation, and will be reflected back to the room by this film, which prevents the heat flow from the room to the outside and reduces the u value of the glass.
so low-e glass appears with the attitude of reducing heat transfer coefficient. what's the masking effect? the composition of the film can also reduce the transmitted solar radiation without affecting the transmission of visible light. therefore, the low-e glass can also reduce the shading coefficient under the condition of high transmittance. the actual low-e glass has a wide range of shading coefficient and can be 0.2-0.7 as needed.