Process conditions in glass furnaces, especially the settings of the combustion system, determine the rate of the evaporation processes at the glass melt surface. Reduction of volatilization to lower dust and heavy metal emissions, to minimize the refractory attack by aggressive volatile components, and to limit depletion of volatile glass components at the glass melt surface is of great technological importance. This can be achieved by changes in burner design and burner positioning, optimising combustion control and avoiding extreme glass surface temperatures. Such high local temperatures at the glass surface may lead to very high concentrations of PbO, NaOH or KOH vapour attacking the crown materials of the furnace.