Publications de Friedrich Linhart

Effects of realistic office daylighting and electric lighting conditions on visual comfort, alertness and mood

Jean-Louis Scartezzini, Friedrich Linhart, Apiparn Borisuit

Lighting conditions in workplaces contribute to a variety of factors related to work satisfaction, productivity and well-being. We tested whether different photometric variables also influence visual perception and the comfort of the lighting, as well as s ...

Sage Publications Ltd2015

Effects of prior light exposure on early evening performance, subjective sleepiness, and hormonal secretion

Jean-Louis Scartezzini, Friedrich Linhart, Apiparn Borisuit, Mirjam Münch

In sighted humans, light intensity, timing, exposure duration, and spectral composition of light are important to entrain the endogenous circadian pacemaker to the 24-h day-night cycle. We tested the impact of two realistic office lighting conditions durin ...

American Psychological Association2012

Evening office lighting - visual comfort vs. energy efficiency vs. performance?

Jean-Louis Scartezzini, Friedrich Linhart

During the study presented in this article, we compared two highly energy-efficient lighting scenarios for evening office lighting (i.e. electric lighting that is typically used for approxiamately 2 h in the evening). The first of these lighting scenarios ...

Elsevier2011

Comparison of objective and subjective visual comfort and associations with non-visual functions in young subjects

Jean-Louis Scartezzini, Jérôme Henri Kämpf, Friedrich Linhart, Apiparn Borisuit, Mirjam Münch

Visual comfort is a key element at work places and at home. Besides task illuminance and color rendering it is the indoor light distribution, which strongly impacts visual comfort. We aimed to show possible relations between subjective and objective visual ...

EPFL2011

Performance of Anidolic Daylighting Systems in tropical climates – Parametric studies for identification of main influencing factors

Jean-Louis Scartezzini, Friedrich Linhart, Stephen Wittkopf

Making daylight more available in buildings is highly desirable, not only for reasons of energy-efficiency, but also for improvement of occupants’ health and well-being. Core-daylighting, that is daylight provision in areas situated at considerable distanc ...

Elsevier2010

Energetic, Visual and Non-Visual Aspects of Office Lighting

Friedrich Linhart

Light has important visual and non-visual effects on humans and high-quality light should therefore be supplied inside buildings in sufficient quantities. On the other hand, artificial lighting is responsible for a large part of an office building's electr ...

EPFL2010

Minimizing lighting power density in office rooms equipped with Anidolic Daylighting Systems

Jean-Louis Scartezzini, Friedrich Linhart

Physical or virtual models are commonly used to visualize the conceptual ideas of architects, lighting designers and researchers; they are also employed to assess the daylighting performance of buildings, particularly in cases where Complex Fenestration Sy ...

2010

Ray tracing study for non-imaging daylight collectors

Raphaël Compagnon, Jean-Louis Scartezzini, Jérôme Henri Kämpf, Friedrich Linhart, Stephen Wittkopf, Lars Oliver Grobe

This paper presents a novel method to study how well non-imaging daylight collectors pipe diffuse daylight into long horizontal funnels for illuminating deep buildings. Forward ray tracing is used to derive luminous intensity distributions curves (LIDC) of ...

2010

Daylight Exposure and Circadian Efficiency in Office Rooms Equipped with Anidolic Daylighting Systems

Jean-Louis Scartezzini, Friedrich Linhart, Mirjam Münch

Anidolic Daylighting Systems (ADS) typically reduce the daylight flux reaching an office room‟s window section and increase it in the rear of the room. They offer interesting possibilities for the combination of comfortable daylighting and highly energy-ef ...

EPFL2009

High Performance Integrated Lighting Systems: Recent Achievements within the Framework of the "Green Lighting" project

Jean-Louis Scartezzini, Friedrich Linhart, Stephen Wittkopf

The „Green Lighting“ project (LESO-PB/EPFL and Swiss Federal Office of Energy) explores different ways to combine advanced day- and artificial lighting technologies for achieving highly energy-efficient office lighting scenarios. This communication gives a ...

EPFL2009

Recent Research on Anidolic Daylighting Systems: Highly Reflective Coating Materials and Chronobiological Properties

Jean-Louis Scartezzini, Friedrich Linhart, Mirjam Münch, Stephen Wittkopf

Making daylight more available in buildings is highly desirable for reasons of energy efficiency, visual comfort, occupant well-being and health. The Anidolic Integrated Ceiling (AIC) is a highly efficient daylighting system, designed to gather and redirec ...

2009

CIE Standard skies in Switzerland: Relative Occurrence and Impact on Daylighting System Performance

Jean-Louis Scartezzini, Friedrich Linhart

The purpose of this work is the definition of a representative sky for the Geneva Lake Region (south-west Switzerland). A representative sky is a theoretical blended sky based on the relative occurrence of a subset of the 15 standard general skies suggeste ...

EPFL2009

Energieeffiziente Bürobeleuchtung - Das Projekt "Green Lighting"

Jean-Louis Scartezzini, Friedrich Linhart

The „Green Lighting“ project, started in 2006 at the Solar Energy and Building Physics Laboratory of Ecole Polytechnique Fédérale de Lausanne (EPFL), explores different ways to combine modern day- and artificial lighting technologies. The main objective of ...

BRENET2008

Occupant satisfaction in office rooms equipped with Anidolic Daylighting Systems

Jean-Louis Scartezzini, Friedrich Linhart

This article presents the results of a satisfaction assessment recently carried out amongst occupants of office rooms equipped with Anidolic Daylighting Systems. Questionnaires and complementary personal interviews were used to reveal which typical office ...

2008

Minimizing connected lighting power in office rooms equipped with anidolic daylighting systems

Jean-Louis Scartezzini, Friedrich Linhart

Electric lighting is responsible for up to one third of an office building’s electricity needs. Making daylight more available in office buildings can not only contribute to significant energy savings but also enhance the occupants’ performance and wellbei ...

EPFL2007

Efficient lighting strategies for office rooms in tropical climates

Jean-Louis Scartezzini, Friedrich Linhart

The “Green Lighting” research project, initiated at the Solar Energy and Building Physics Laboratory (LESO-PB) of the Swiss Federal Institute of Technology in Lausanne (EPFL), is aiming at an energy efficient integration of advanced daylighting and electri ...

2007

Green Lighting project focuses on energy-efficient offices (in SPIE Newsroom)

Jean-Louis Scartezzini, Friedrich Linhart

2007

Design of a software tool for PV-system-specific lightning protection

Friedrich Linhart

Photovoltaic (PV) systems are often installed on rooftops or as freestanding systems with no higher surrounding structures. This is why they are often exposed to the influences of lightning which can severely damage these expensive systems. Lightning prote ...

2006