Induction Lamp in Renovation
Project Team at Lighting Laboratory
- Research Scientist, D.Sc.(Tech.) Eino Tetri
Lighting renovation was carried out in the main auditorium of the main building of Helsinki University of Technology. In the auditorium the replacement of lamps is very difficult and therefore also expensive. Long lamp life was the major requirement for the light source in this space and the renovation had to be carried out using the original luminaires. The lighting renovation was done using an induction lamp. The chosen lamp was Philips QL 85W, whose luminous flux is 6000 lm and system efficacy 70 lm/W. Estimated lamp life is 60000 hours with a failure rate of less than 20%. Lumen maintenance after 60000 hours is 70% of the initial luminous flux. There are some 2500 annual operating hours in the auditorium. When the luminaire is equipped with tungsten filament lamp, the group replacement of lamps is needed twice a year, with compact fluorescent lamps every third or fourth year and with induction lamps once in 24 years. With induction lamps the illuminance in the auditorium was almost doubled.