Post Time：Dec 22,2016Classify:Industry NewsView：800
Insulating glass has the feature of thermal insulation. This is what we know from the daily use. So why is it? Our company intend to explain it.
Pay attention, if we want to know the thermal insulation of insulating glass we must firstly understand the component parts-thermal resistance of glass and air.
1Thermal resistance of glass
Heat conductivity of normal glass is 0.77W/m2K, which is twice of air. If we want to strengthen the thermal resistance of glass we need to select some glass with special features instead of increase the thickness of glass. For example: Low-e glass’s transmittance to visible light is the same as normal glass, but it can reflect back the infrared and ultraviolet inside the room, which can avoid a heat lost in room. This is applicable to cold regions. Heat reflecting glass can reflect back the most of solar energy and resist the solar energy entering into the room. This is applicable for the regions needed to be installed with refrigerator. Heat-absorbing glass has a strong absorptivity to heat and it can release after absorbing the solar heat. It can better resist the solar energy entering into the room if you add a reflective film on side of the heat absorbing glass.
2Thermal resistance of air layer
0.028W/m2K, conductivity of air, is small. There is no air convection between the double panes, thus the resistance can be easily strengthened if the we increase the thickness of air layer. The relation between the air layer thickness D and the insulating glass conductivity K is as following: there is no convection in the air layer when D is less then 10mm and when D increases and K reduces, if D becomes larger than 10mm, the convection will become stronger and stronger. But when D is larger than 20mmm then K hardly changes. Considering the heating insulation effect and economical efficiency, 12mm is the best thickness of air layer. Heating insulation effect can also be strengthened if we use such low conductivity gas Argon instead of air between the double panes.
3Thermal resistance of insulating glass
Thermal resistance of insulating glass R=RI ∑RG ∑RA RO, and RO is inner. To specific place the thermal resistance of outer side will be fixed.
Source: glassinchinaAuthor: shangyi
