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

Lee, Sujung; Yoon, Heakyung

doi:10.3390/app11188313

Cited by 5 publications

(4 citation statements)

References 33 publications

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“…One explanation for the lack of detectable impact from CRI could be that the span between the colour rendering indexes needs to be greater in order for the human eye to perceive clearer differences. However, Lee and Yoon [38] reports an effect on the acceptance of office lights of CRIs that varied from below and above 80, and with similar spans to that in our sub-study. Another explanation may be that there are additional colour characteristics of the light sources that influence the perception more considerably.…”

Section: -1-1-influence Of the Properties Of Light Sources On Perceiv...supporting

confidence: 82%

“…This may be due to physically measurable deviations from the light distribution from an ideal blackbody [29,30], to human perception [31,32], or to human eyesight being very sensitive to these colour differences [28,33], as is known from colour research [34,35]. Perception in general [36], and not least colour vision [37], is also context-dependent and is affected variously by the different properties of light sources, such as colour temperature and colour rendering [38][39][40]. There are, however, no (precise) measures to describe perceived differences in light colour.…”

Section: -1-2-physical and Visually Perceived Measures Of Light Quali...mentioning

confidence: 99%

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User-Centric Measures of the Perceived Light Qualities of Lighting Products

Hiller

Boork²,

Enger³

et al. 2023

Emerg Sci J

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Nowadays, lighting planning is predominantly determined by the need to meet physically measurable requirements that are often based on current lighting standards. However, meeting the minimum technical requirements of the standards is no guarantee for a visually appealing light environment. Instead, requirements based on perceived light qualities also need to be included to achieve better user comfort. Taking perception-based qualities into consideration when creating a light environment is, for many, not an easy task. In addition, a common terminology for perceived light qualities is currently lacking, both in industry and in research. The aim of this paper is, therefore, to explore how perceived light qualities of white light sources can be described when employing user-centric measures. The focus was on the qualities of light colour and diffuse and distinct light since these qualities have a great impact on the visual impression of light. The perception was assessed by applying analytical sensory analysis to lighting products, a method found to be promising in previous work. The methodology is based on analytical measurement by the human senses, which is particularly valuable when developing a general terminology. Since sensory analysis is still quite new to the topic of lighting, the applicability of using the methodology to assess lighting in a real context was also investigated. The results of the studies showed that the perception of light qualities can be described using further concepts in addition to those currently used. For light colour, the concepts of reddish, bluish, yellowish, and greenish light colours proved suitable for providing a richer description of the quality. The concepts of diffuse and distinct light satisfactorily captured variations in light contrast produced by shadows, reflections, and sparkles. In addition, the studies revealed that analytical sensory analysis was applicable for assessing the perception of lighting in a real-world context. The latter means that knowledge gained in the laboratory can be translated into real environments. The user-centric measures investigated in this paper have contributed to the terminology related to perceived light qualities. These can complement the physical measures in lighting planning to promote light environments that are not only energy efficient and meet technical requirements, but also cater for increased user comfort. Doi: 10.28991/ESJ-2023-07-02-022 Full Text: PDF

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Section: -1-1-influence Of the Properties Of Light Sources On Perceiv...supporting

confidence: 82%

Section: -1-2-physical and Visually Perceived Measures Of Light Quali...mentioning

confidence: 99%

User-Centric Measures of the Perceived Light Qualities of Lighting Products

Hiller

Boork²,

Enger³

et al. 2023

Emerg Sci J

View full text Add to dashboard Cite

show abstract

“…In our study, we designated the desk area as the primary focus for lighting assessment, selecting one central point along with four corner points for the measurement of lighting parameters to ensure uniform illuminance across the area. Throughout the experiment, the Color Rendering Index (CRI) was maintained above 79, indicating a light source that basically renders colors compared to natural light [35]. The uniformity of illuminance was kept above 0.7, ensuring that light distribution was even and consistent.…”

Section: Experimental Environmentmentioning

confidence: 99%

Enhanced Visual Performance for In–Vehicle Reading Task Evaluated by Preferences, Emotions and Sustained Attention

Ni,

Weirich,

Lin

2024

Applied Sciences

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The proliferation of electric and hybrid vehicles has made it possible for people to read and work in a stationary vehicle for extended periods. However, the current commonly used in–vehicle lighting design is still centered around driving and driving safety. Following recommendations from the literature, a neutral white color band (4000 K–5000 K) with 50–100 lx at the vehicle table area is favored. Whether this lighting environment can meet the needs to enhance the reading performance in a modern vehicle was investigated in this presented study. Therefore, in total, 12 lighting settings were designed based on combinations of four illuminance levels (50 lx, 100 lx, 150 lx and 200 lx) and three correlated color temperatures (3000 K, 4000 K and 5000 K); we recruited 19 subjects (12 females, 7 males) and let study participants evaluate each condition based on electronic and paper reading. Next, subjective preferences, positive and negative emotions, feeling of fatigue and sustained attention were tested. We found that higher illuminance and higher CCT (Correlated Color Temperature) can significantly improve the performance of in–vehicle readers in most aspects following Kruithof’s law (p < 0.05). Among them, we recommend the combination of 150 lx and 4000 K as the light parameters for in–vehicle reading as a new development guideline. In addition, we also discovered the inconsistency of people’s lighting preferences between in–vehicle spaces and conventional spaces. For indoor lighting, illuminance values up to 1000 lx are still favored. For an in–vehicle function, starting with 200 lx, the preference level and reading performance already declined. In comparison between electronic and paper reading, both were similarly evaluated. These results show that a neutral white light color should be chosen with a horizontal illuminance of maximal 150 lx for a reading light function independent of the reading device. Interdisciplinarily speaking, our findings can be applied in similar small spaces or transportation modes with gentle acceleration and deceleration such as small space hotel rooms, trains, airplanes or ships.

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“…The HCL-based for subjective assessment instrument of light environment quality seen from the visual category can be seen in Table 2. Problem-solving Decreased -Increased 7 [26] Several articles assessing the light environment quality based on the subjective assessment of respondents in the visual category can be divided into 7 categories: visual comfort, visual discomfort, visual sensation, lighting level, glare sensation, light distribution, and productivity/readability. There is no specific standard to judge the visual quality of a light environment.…”

Section: Human-centric Lighting Based For Subjective Assessment Instr...mentioning

confidence: 99%

Subjective Assessment of Light Environment Quality based on Human-centric Lighting

Vidiyanti

Wonorahardjo

2023

IOP Conf. Ser.: Earth Environ. Sci.

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The light environment quality, in general, can be assessed from various metrics of that have been made by standard institutions such as the Indonesian National Standard (SNI), Illuminating Engineering Society (IES), or the International WELL Building Institute. However, the development of research in the field of lighting has shifted from focusing on visual quality and energy to Human-Centric Lighting (HCL). HCL requires an assessment metric to measure quality from the subjective point of view of occupants. There are two types of subjective judgments in light environment quality research, that are subjective judgments for post-experiment conditions and subjective judgments for pre & post-experiment conditions. Subjective assessment of the light environment quality based on Human-centric Lighting can be divided into three categories, that are visual, emotional and biological assessments. For the subjective assessment instrument of the visual category, researchers can use the glare sensation assessment standard. Meanwhile, for the assessment of the light environment quality from the emotional category, there is no specific standard. And for assessing the light environment quality from the biological category, researchers can use commonly used assessment standards, such as the Karolinska Sleepiness Scale (KSS), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). For an assessment category that does not have a standard, the researcher can arrange a research instrument from the results of the literature review and adapt it to the conditions of the research study object.

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

Cited by 5 publications

References 33 publications

User-Centric Measures of the Perceived Light Qualities of Lighting Products

User-Centric Measures of the Perceived Light Qualities of Lighting Products

Enhanced Visual Performance for In–Vehicle Reading Task Evaluated by Preferences, Emotions and Sustained Attention

Subjective Assessment of Light Environment Quality based on Human-centric Lighting

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