Heat is transmitted in three ways: conduction, convection, and radiation. In comparison with regular glass, the vacuum chamber between the glass panes effectively minimizes the heat transfer by reducing gas conduction and convection to a level low enough

Heat is transmitted in three ways: conduction, convection, and radiation.

①Heat conduction: refers to the movement of heat from a solid object with a higher temperature to another with a lower temperature. Thermal conduction in gases often takes place together with convection at the same time.

②Heat convection: refers to the transfer of heat by the circulation or movement of the heated parts of a liquid or gas from a hotter area to a cooler area to reach a balanced temperature. Convection is a unique way of heat transfer taking place in liquid and gas. The convective phenomenon in gas is more obvious than in a liquid.

③Heat radiation: A matter emits thermal radiation due to its temperature. The thermal transfer of this type is called thermal radiation. Although thermal radiation is one of the thermal transfer mechanisms, it transfers heat in a way different than heat conduction and convection. It does not transfer heat from one object to another through any media. Thermal radiation is electromagnetic radiation emitting energy. Higher the temperature, the stronger the radiation.

In comparison with regular glass, the vacuum chamber between the glass panes effectively minimizes the heat transfer by reducing gas conduction and convection to a level low enough to be ignored. Other than heat conduction via frames and spacers, heat is primarily transferred through radiation in vacuum insulated glass. The radiation can be further reduced by using Low-E coated glass panes to achieve a lower U-value.