IRC is a patented process. The abbreviation stands for Infrared Coating. This special coating is applied to the outside of the lamps and acts as a kind of mirror. It reflects the infrared heat radiation back onto the coil. This, along with the special bulb geometry, means that the coil is additionally heated. This means that bringing the coil up to the operating temperature needs less electrical energy. This heat recovery increases the efficiency of the lamp. Lamps with IR coating can reach a service life which is more than double that of standard halogen lamps under the same conditions. Due to the optimum geometric conditions, the IRC process is primarily used by LEDVANCE for the halogen low voltage lamps (twelve Volts).
The filling gas in the lamp removes a large proportion of the heat from the coil. This means that additional energy must be fed into the coil to keep it at the same temperature. The heat loss depends on the type of filling gas in the lamp. Using xenon as a filling gas instead of the noble gas argon for example means this heat loss can be reduced.
How does that work?
The larger the atoms of a gas are, the lower its conduction of heat and the resulting heat loss will be. Xenon is a gas with low conductivity. Through its use, and the resulting lower heat loss, less electrical energy is required to heat up the coil. In addition to that, the heavy xenon atoms also slow down the evaporation of the tungsten atoms from the coil. This reduces the material loss on the coil and the service life of the lamp is lengthened accordingly. However, xenon is a very rare noble gas and is therefore expensive. Nevertheless, OSRAM still uses xenon as the filling gas for all the high quality halogen lamps so as to be able to offer the best possible halogen lamps.