LENI Calculations

LENI stands for Lighting Energy Numeric Indicator and enables an accurate calculation of the efficiency of an entire lighting installation. This includes the use of controls within a specific setting and is based on the required illuminance of a space as well as the number of luminaire operating hours per year.

The LENI methodology can be found in the current edition of EN 15193-1 and is also the lighting energy calculation method recommended in the building regulations guidance notes for the conservation of fuel & power in some countries – Building Regulation Part L, Volume 2 for Buildings Other Than Dwellings (England) and also in Austria & the Republic of Ireland

LENI looks at:

• The predicted energy in use by the indoor and emergency lighting solutions as well as lighting control devices in place across an installation.

• The total power consumption of the indoor lighting installation

• Energy saved by the control system for predicted net lighting energy consumption for automatic occupancy detection, daylight linked electric lighting and constant illuminance control.