Foto: SOL4 Büro- und Seminarzentrum Eichkogel

LessIsMore - Energy efficient human centric lighting by innovative components and daylight integration

Human Centric Lighting (HCL) is focused on the positive visual and non-visual (biological) effects of light on humans, but is wasting energy by the inefficient use of components and daylight. In LessIsMore an exemplary pilot installation will be developed and evaluated.

Short Description



Starting point / motivation

In the last years the interest in Human Centric Lighting (HCL) has grown substantially, it is estimated that the European HCL-market will have increased ten-fold by 2020.

These illuminations focus on the positive visual and biological effects of light on human beings and hence influence the human health positively in the long term.

Ordinarily, HCL illuminations include complex artificial lighting control mechanisms including sensors, which vary the light colour and the intensity dynamically dependent on the time of day. However, up to this day HCL illuminations are solely focused on the generation of biological effects, energy efficiency is generally neglected.

Contents and goals

Due to the expected increase of HCL illuminations a great part of energy saving achieved through the use of LEDs is equalized and unnecessary new energy losses will arise. And yet the high energy consumption of such lighting installations can primarily be attributed to the ignorant and inefficient usage of the individual constituents of the lighting constituents (concepts of illumination, optics, LED-drivers, sensors, control algorithms) and the lack of effective daylight integration.

The goal of the research project LessIsMore is therefore to develop a biodynamic lighting installation with utilization of daylight where the optimized use of the lighting constituents is tested and the flaws of the present HCL illuminations will be eradicated. The developed lighting installation is expected to have a positive biological effect on humans and at the same time should be as energy-efficient as possible.


To develop an optimized lighting concept for energy efficient HCL illuminations, LessIsMore aims to efficiently combine, optimize and evaluate the constituents of illumination in a test installation.

Different lighting concepts will be investigated in regard to their biological efficacy and their energy consumption, subsequently a functional model of a HCL luminaire will be developed containing controllable direct and diffuse optical components, lighting constituents (illuminants, optical components, LED-drivers, sensors) will be selected and installed deliberately and connected through an intelligent, integral control algorithms including the use of a daylighting system.

In such an optimized lighting installation about 62% of the total energy consumption of artificial lighting could be conserved.

Expected results

After the end of the project a functioning lighting installation including the functional model of a new HCL luminaire, optimized lighting constituents and a daylight system should exist with an intelligent control mechanism in a test room.

The best strategy for illumination and lighting control, respectively, to couple energy efficiency and HCL was researched and developed as well as evaluated and optimized in a yearlong trial installation according to their effects onto humans and energy efficiency.

The resulting knowledge and know-how for lighting design will be summarized in guidelines and tips for practitioners.

Project Partners

Project management

Bartenbach GmbH

Contact Address

Bartenbach GmbH
Rinner Straße 14
A-6071 Aldrans
Tel.: +43 (512) 3338 0
Fax: +43 (512) 3338 88

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