In rooms where luminaires are placed up high, a centralised emergency lighting system is often preferable. With a decentralised system, the luminous flux is often not sufficient as the light source in such a system is operated with greatly reduced effect. With a central solution there is almost the same luminous flux in emergency mode and in normal operation, and furthermore the risk of difficult battery changes is avoided. Even in high risk areas, where higher lighting strengths are important, a central emergency lighting system often works better than a decentralised one.
Centralised emergency lighting systems also work well in cold areas or outdoors, assuming that the central emergency lighting unit is placed at normal room temperature (indoors).