Frank Opferkuch

Bio: Frank Opferkuch is an academic researcher. The author has an hindex of 2, co-authored 2 publications receiving 7 citations.

Standardizing Melanopic Effects of Ocular Light for Ecological Lighting Design of Nonresidential Buildings—An Overview of Current Legislation and Accompanying Scientific Studies

Abstract: DIN SPEC 5031-100 and CIE S 026:2018 are regulatory frameworks that are intended to establish health-preserving indoor lighting in Europe. Therefore, they are crucial for the visual environment and its sustainability. The standards are largely congruent. Inconsistencies should now be harmonized with the newly published draft standard DIN/TS 5031-100, for which the objection period ended on 3 June 2020; thus, it can be expected that the standard will soon be put into operation. This publication provides the reader with a detailed technical as well as medical overview of the scope and background information on how the standard came about. Applicable laws, ordinances and standards were compiled across countries, and related studies were reviewed. It is demonstrated that the focus of this new standard, as with previous versions, is on the melanopic sensitivity of ganglion cells. The authors base this on a literature search for projects about ecological lighting design over the past 20 years. However, in practice, the publication of the standard does not yet completely counteract the health effects of inappropriate indoor lighting.

Digitalisierung für alle? Zur Auswirkung digitaler Angebote auf Teilhabechancen von Wohnungslosen

Abstract: Das an der Technischen Hochschule Nurnberg Georg Simon Ohm angesiedelte Forschungsprojekt „SIWo – Smart Inklusion fur Wohnungslose“ widmet sich der Fragestellung, welche Informations‑, Unterstutzungs- und Beratungsbedarfe bei wohnungslosen Menschen vorliegen und in welcher Form sich die Teilhabechancen fur die heterogene Zielgruppe wohnungsloser oder von Wohnungsnot betroffener Menschen mittels digitaler Hilfe und Beratungsangebote verbessern lassen. Hierfur werden zum einen mit Gruppendiskussionen und qualitativen Interviews Bedarfe identifiziert. Zum anderen sollen im Rahmen des Projekts prototypische Losungsansatze in Form einer plattformubergreifenden Hilfe-App entwickelt, getestet und mit Evaluationsverfahren begleitet werden. Charakteristisch ist dabei die enge interdisziplinare Zusammenarbeit zwischen Sozialwissenschaft, Informatik und Energietechnik, die partizipative Begleitung des Projekts durch Wohnungslose und andere Stadtakteur*innen, sowie der Fokus auf interaktive Funktionen, die digitalisierte Begegnungsraume ermoglichen und Interaktionen auch zwischen Bevolkerungsgruppen fordern, die i. d. R. eher wenig miteinander zu tun haben. Dieses Vorgehen begreift somit Wohnungslosigkeit nicht ausschlieslich als professionelles Arbeitsfeld der Sozialen Arbeit, sondern als gesamtgesellschaftliche Aufgabe.

Systematic review of light exposure impact on human circadian rhythm

Abstract: Light is necessary for life, and artificial light improves visual performance and safety, but there is an increasing concern of the potential health and environmental impacts of light. Findings from a number of studies suggest that mistimed light exposure disrupts the circadian rhythm in humans, potentially causing further health impacts. However, a variety of methods has been applied in individual experimental studies of light-induced circadian impacts, including definition of light exposure and outcomes. Thus, a systematic review is needed to synthesize the results. In addition, a review of the scientific evidence on the impacts of light on circadian rhythm is needed for developing an evaluation method of light pollution, i.e., the negative impacts of artificial light, in life cycle assessment (LCA). The current LCA practice does not have a method to evaluate the light pollution, neither in terms of human health nor the ecological impacts. The systematic literature survey was conducted by searching for two concepts: light and circadian rhythm. The circadian rhythm was searched with additional terms of melatonin and rapid-eye-movement (REM) sleep. The literature search resulted to 128 articles which were subjected to a data collection and analysis. Melatonin secretion was studied in 122 articles and REM sleep in 13 articles. The reports on melatonin secretion were divided into studies with specific light exposure (101 reports), usually in a controlled laboratory environment, and studies of prevailing light conditions typical at home or work environments (21 studies). Studies were generally conducted on adults in their twenties or thirties, but only very few studies experimented on children and elderly adults. Surprisingly many studies were conducted with a small sample size: 39 out of 128 studies were conducted with 10 or less subjects. The quality criteria of studies for more profound synthesis were a minimum sample size of 20 subjects and providing details of the light exposure (spectrum or wavelength; illuminance, irradiance or photon density). This resulted to 13 qualified studies on melatonin and 2 studies on REM sleep. Further analysis of these 15 reports indicated that a two-hour exposure to blue light (460 nm) in the evening suppresses melatonin, the maximum melatonin-suppressing effect being achieved at the shortest wavelengths (424 nm, violet). The melatonin concentration recovered rather rapidly, within 15 min from cessation of the exposure, suggesting a short-term or simultaneous impact of light exposure on the melatonin secretion. Melatonin secretion and suppression were reduced with age, but the light-induced circadian phase advance was not impaired with age. Light exposure in the evening, at night and in the morning affected the circadian phase of melatonin levels. In addition, even the longest wavelengths (631 nm, red) and intermittent light exposures induced circadian resetting responses, and exposure to low light levels (5-10 lux) at night when sleeping with eyes closed induced a circadian response. The review enables further development of an evaluation method of light pollution in LCA regarding the light-induced impacts on human circadian system.

Stakeholder and value orientation in digital social innovation: Designing a digital donation concept to support homeless neighbors

Abstract: During the first wave of COVID-19 lockdowns, the infrastructure for supporting homeless neighbors disintegrated in many countries As one important area of support, it became difficult to provide small donations to homeless neighbors In an action design research-based project, as part of a national hackathon initiative and accelerator program, we contributed to the development of a digital donation concept We frame this process as a digital social innovation for vulnerable people and highlight the need to consider stakeholder and value orientation during the design, implementation, and evaluation stages Our findings include a reflection of the project course, a description of the developed concept, an analysis of how values shaped the design, and a formalization of learnings © 2021 IEEE Computer Society All rights reserved

A Randomized Controlled Trail for Comparing LED Color Temperature and Color Rendering Attributes in Different Illuminance Environments for Human-Centric Office Lighting

Abstract: In this study, two experiments were conducted to investigate the effects of the color rendering index (CRI) and correlated color temperature (CCT) of light-emitting diode (LED) lighting on office user acceptance and to explore the proper color attributes for human-centric office lighting. Experiment 1 had four LED lights, with two levels for the CRI (CRI < 80: 79, 76; or CRI ≥ 80: 83, 84) and CCT (3000 K or 6500 K) at 300 lux. In experiment 2, there were four LED lights, with several levels for the CRI (CRI < 80: 78; or CRI ≥ 80: 87, 83) and CCT (3000 K or 6500 K) at 500 lux. Ninety-six participants in experiment 1 and ninety-four participants in experiment 2 performed a reading task. The results in experiment 1 and experiment 2 showed that LEDs with lower CRI values at warm color temperatures were rated as more acceptable than LEDs with higher CRI values at warm color temperatures. However, the positive effect extended to LEDs with higher CRI values at cool temperatures but not to LEDs with lower CRI values at cool temperatures. Therefore, the findings are that LEDs with lower CRI values at warm color temperatures and LEDs with higher CRI values at cool temperatures provide the right level of color attributes for office lighting.

The Future of Interior Lighting Is Here

Abstract: One word that characterizes the situation in the lighting industry during recent years is “change” [...]

Role of Architectural Design in Creating Circadian-Effective Interior Settings

Abstract: Daylight variability throughout the day makes it an ideal light source for the stimulation of humans’ circadian systems. However, the key criteria, including proper quantity, quality, and hours of access to daylight, are not always present inside the built environment. Therefore, artificial light is necessary to complement the human’s visual and non-visual needs for light. Architectural design parameters, such as window area, orientation, glazing material, and surface reflectance alter the characteristics of both daylight and artificial light inside buildings. These parameters and their impact on lighting design should be considered from the early design stages to attain a circadian-effective design. In response to this need, a design approach called Human-Centric Lighting (HCL) was introduced. HCL places humans, and their visual and non-visual needs, in the center of the design process. It manipulates the light-related factors, such as spectrum and intensity, within the built environment for circadian benefits. The effect of HCL on lighting energy efficiency is still not clear. This paper reviews essential architectural design parameters and their impacts on circadian lighting design, considers the HCL design process and explores the most widely used circadian lighting metrics and standards.