THERMAL INSULATION

Heat Conduct is a phenomenon in which thermal energy is transferred due to the contact of various mass points in the same substance.

Glass is good heat conductivity through which far infrared is quite easy to penetrate from the higher temperature side to the low temperature side.

Heat transfer is the flow of liquid or gas caused by thermal expansion, the hot part rises, and the cold part falls, thereby transferring heat energy. That is, the energy transfer caused by the movement of an object from a certain area of ​​space to another area of ​​different temperature.

Heat radiation means that the heat energy becomes radiant wave energy and is directly emitted. When it reaches an impermeable substance, it is absorbed by it and then becomes heat energy;

In glass industry,the heat radiation means glass itself have high temperature after absorbing solar energy and becomes heat energy itself.

Different from normal clear glass and low iron glass,body tinted glass ,body tinted glass -Grey,Bronze,Green,Pink etc can absorb solar energy and makes glass surface temperature much higher,then conduct the heat to interior surface.

Body tinted glass have same U value with normal glass but much lower SC value.

For single piece glass and laminated glass,glass itself is good heat conductivy.Insulated glass is quite different,the spacer between 2 glass panels ,becomes the only materials that allow heat been conducted from the exterior piece glass to the interior one.

As the spacer is quite slim and small,only limited heat can be conducted and the space created also limited the heat convection and decrease the glass U value.

• The spacer materials can be aluminium spacer,stainless steel spacer,warm edge spacer,superspacer,TPS, the smaller thermal conducvity materials,the better U value,
• Standard Spacer thickness is 12mm,16mm,18mm,but bigger space doesn’t mean better U value,Once space thickness is over 20mm,the U value will decrease slightly and even increase on the contrary.
• Argon.Argon can replace the air between glass,This inert gas can decrease overall glass U value by 0.2W/M2.K through decrease the thermal conducvity.
• Triple insulated glass is recommended to get better U value and SC value,this is the typical glass configuration for passive house glass.

Hard coated Low-E ,also named online low-E coating,it’s a functional coating with low radiation performance on the glass surface on the float line by chemical vapor deposition and special materials on the float glass production line.

The main function of the coating is to decrease glass heat radiation.Hard coated low-E emmisivity is about 0.15,the biggest advantage of hard coated low-E is,its chemical performance and firmness is quite good,can be used as single piece glass, and laminated glass,insulated glass.

In China,only AGC and SYP ,Jinjing glass produce limited hard coated low-E glass:Planible G,Sunergy,SY-48,Energy Advantage,SGE60,SGC60,performance data in below table:

Soft coated low-E,also named as off-line low-E,it is generally vacuum-magnetized sputter coating process, and a multi-layer composite film is coated on the surface of the glass to realize Low-E function. The main functional film layer in the film layer is generally silver (Ag) film, which can be subdivided into single silver low e, double silver low e and triple silver low e.

Soft Coated low-E glass emmisivity is much lower than hard cated low-E,emmisivity is usually below 0.1,and most advanced triple silver low-E,for example,solarban 70XL,emmisivity is only 0.03.

The only sortage of soft coated low-E is can only been insulated inside the IGU,it’s easy to be oxidized and dameged once been exposed in the air.

In China,there’re hundreds of soft coating lines producing all kinds of soft coated low-E products,available glass substrate can be clear,low iron,body tinted glass etc,light transmittance varies from 10%-85%,and SC value varies from 0.2-0.65,below are some sample low-E performance we produce:

The vacuum glass is also made with 2 pieces single piece glass and spacer.The difference is ,Vacuum glass has a 0.2-0.4mm vacuum space between 2 piece glass,some mineral supporting points are placed between the glass to ensure that the vacuum glass won’t shrink.

Its thermal performance is 2-4 times that of insulated glass,6-10 times that of single piece glass.

The vacuum glass sound insulation reach 39mm,which is equal to triple laminated glass,and is higher than any glass products in the market now.