The three heat transmitted ways are conduction, convection, and radiation. The vacuum chamber between the vacumm insulated glass panes effectively minimizes the heat transfer compared with regular glass.

The primary features of vacuum glass are thermal Insulation,noise reduction and anti condensation.

K-value is simply shorthand for thermal conductivity,U-value, known officially as thermal transmittance and R-value, know as thermal resistance,is used to reflect the ability to resist heat flow by thermal insulating materials.

Vacuum insulated glass is developed based on the principle of Dewar flask (i.e. vacuum flask), where the vacuum layer is used to reduce gas conduction and convection to achieve features such as heat insulation, energy saving and noise reduction,etc.

Physicist Torricelli proved the presence of vacuum and atmospheric pressure in natural space.To commemorate Torricelli in scientific discoveries and contributions, the torr, a conventional unit of pressure used in vacuum measurements, is named after him.