a unique harmony of

comfort, esthetics & efficiency

The LIBUS SBL point / directional light source distribution control system represents a new big step forward in LED lighting with real concrete solutions for:

  • Energy efficacy, considerably higher than “ecodesign” requirements
  • Glare control, (UGR < 10) far better than industry standard (UGR < 19)
  • Beam & distribution control, light exactly where you need it

In existing back-lit and / or  edge-lit LED general  lighting  luminaires,  the point / directional light source is simply transformed into a plane / surface raw light source  again, by means of opal or clear micro-prismatic diffusers. This mainly visual transformation is achieved at the cost of 18% to 35% light – energy loss but these light forms are still raw light sources since, they still do not provide meaningful control over light distribution or other optical properties demanded from an adequate luminaire. Controlling light intensity and distribution through a sight block louver (SBL) system, instead of opal plastic diffusers :

LIBUS provides over a 94% light output ratio (L.O.R.) which translates up to 175 lumen per watt efficacy

A UGR level less than 19, specified as the acceptable upper glare limit of the industry  in general indoor lighting, in reality, still can cause not merely simple eye discomfort but also adverse side effects such as tenseness and difficulty focusing resulting in production loss, mistakes, work accidents  and  even insomnia. Due to precise beam control of the LIBUS SBL system, effective lumen values (lumens reaching the target working plane) are exceptionally high (up to an average 97% of the UF table), meaning fewer luminaires and/or less power needed to achieve the target lux level on the working plane in comparison to existing conventional LED panel systems (UF: ± 70% to 74%) . High efficacy coupled with high UF figures permits very low (i.e.,down to 11-15watts nominal system power or  0,08 watt power load per LED in a 60×60 luminaire) power consumption and this low power levels allows SBL luminaires to:

  • a. have higher lumen performance of individual LEDs
  • b. generate very low junction temperature (Tj max.57°C) which, consequently maintains a life expectancy (mean rated service life L80B10 - tq25 °C) over 50.000 hrs., with no or negligible color shift and preserved high chromaticity stability

GLARE is no longer
“ inevitable ”
in LED lighting …


Although it cannot be achieved by most of the LED lighting luminaires available in the market, the glare rate of UGR less than 19, which is specified as the acceptable upper glare limit of the industry for general indoor lighting, in reality, as reported in many serious medical publications, still causes not merely simple eye discomfort but adverse side effects including tenseness and focusing difficulty resulting in production loss, mistakes, work accidents and even insomnia.

Esthetics & Design

All, almost identical copies of each other, white plastic led panels or led spots are no longer the only available design or optical alternatives when switching to LED lighting from fluorescent for energy efficiency…

Light Beam & Distribution Control


As the widely used industrial option in general indoor led lighting, led panel luminaires in various forms, all emit generated light to the room in all directions without any beam and distribution control.


The SBL system LIBUS LED lighting luminaires precisely control light distribution and transmit 90% – 97% of the generated light to the target working plane.

Energy Efficiency

Existing indoor lighting luminaires produce the following luminous flux (lumens) on average by consuming 1 watt energy:

Traditional T8 fluorescent lamp : ±45 lumens
Energy efficient T5 fluorescent lamp : ±65 lumens
Led slim panel / edge-light : ±95 lumens
Led panel / back-light : 100 – 120 lumens
Led COB spot & down-lights : 75 – 125 lumens

The standard / low-budget LIBUS LED lighting luminaires generate 116-125 lm/w and energy efficacy reaches up to 175 lm/w in performance types;

Fluorescent lamp LED Panel Libus
100% 69% 47% 41% 36% 31% 26%
± 45 lm/w ± 65 lm/w ± 95 lm/w ± 110 lm/w ± 123 lm/w ± 145 lm/w ± 172 lm/w

Average / approximate output values of existing luminaires were taken into consideration in above evaluations. Please ask for photometric test reports of LIBUS luminaires made by accredited laboratories for definite / specific comparisons.

These figures indicate a lower energy consumption of :

  • 3 to 4 times in conversions from fluorescent luminaires
  • 1.3 to 1.8 times in conversions from led panel luminaires

In addition to direct savings in monthly energy bills, LIBUS, already exceeding ecodesign efficacy requirements, guarantees an efficient +50.000 hr. luminaire life (L80B10) , free of lamp replacement cost.

  • +50.000 hr. : ± 30 years based on average annual 252 working days & daily 6.5 operating hr.
  • L80B10 : A minimum of 80% of the luminous flux will be maintained for a defined period given the maximum ambient temperature and a minimum of 90% of the luminaires in the installation will respond to the level of maintenance of the defined luminous flux.

Project Support

LIBUS provides free technical support and lighting design service in projects where Libus luminaires are used / offered.