TRILUX Luminaires - Proljus AB

Refurbishment example
The following presents a reference calculation
between a system with high-pressure
mercury vapour lamps and high-pressure
sodium-vapour lamps as a sample application
for the energy-efficient refurbishment
measure of a road lighting system.
Here the installation geometry is defined
as follows:
(Maximum) light point height h 8.00 m
Light point distance a 35.00 m
Width of the traffic lane b 6.50 m
Number of traffic lanes 2
Width of a traffic lane 3.25 m
Light distribution overlap s -0.5 m
Luminaire inclination δ 15.0 °
Calculation results for viewer B1
Following project planning data
were taken as a basis:
Old installation New installation
Average luminance L m / cd/m² 0.56 0.63
Total uniformity U o 0.36 0.53
Longitudinal uniformity U l 0.46 0.6
Threshold value increase TI / % 13.2 11.8
Mean illuminance E m / lx 9.34 9.51
Total uniformity U o 0.32 0.3
Surrounding illuminance ratio 0.79 0.5
Maintenance factor 0.8
Lighting class ME5
Maintenance value of the illuminance 0.50 cd/m²
Total uniformity Uo 0.35
Longitudinal uniformity Ul 0.4
Threshold value increase TI 15 %
Surrounding illuminance ratio SR 0.5
Number of calculation points 12/6
Standard road surface C2
Average luminance coefficient 0.07 (cd/m²)/lx
Lamp equipment of old installation: 2 x 125 W HME, overall luminous flux 12600 lm
Lamp equipment of new installation: 1 x 70 W HST, overall luminous flux 6600 lm
Conclusion
The calculation results for the new installation
are not only better, but are also relevant
especially with regard to the anticipated
energy savings. The system rating of a light
point of the old installation is 274 W compared
to the new installation with a system
rating of only 83 W. This results in a 30.3%
savings in energy costs with better photometric
values.
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Technical information