A field study of fluorescent and LED classroom lighting

Gentile, Niko; Govén, Tommy; Laike, Thorbjörn; Sjöberg, Klas

doi:10.1177/1477153516675911

Cited by 40 publications

(43 citation statements)

References 25 publications

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“…Though the visual light emitted from LEDs and florescent lamps have the same visual appearance, LEDs emit more non-visual light within the blue spectrum (450 nm) compared with fluorescents with the same CCT level [11]. Fluorescent and LED both have the capability of meeting the various light out-put and coloring needs, however, fluorescent lamps use phosphor coatings to improve color perception, such as full-spectrum fluorescent, which emulates daylight and diffuse UV radiation.…”

Section: Fluorescent Led and Correlated Color Temperature Overviewmentioning

confidence: 99%

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The impact of fluorescent and led lighting on students attitudes and behavior in the classroom

Morrow¹,

Kanakri²

2018

apr

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Introduction: This study examined empirical research on the effects of high correlated color temperature light-emitting diodes (LED) and fluorescent lighting on students in the classroom. LED is becoming the most recent lighting option for optimal energy efficiency over fluorescent technology. Background: A review of the literature indicates correlated color temperature (CCT) of lighting has nonvisual effects on students, with higher CCT positively impacting attitudes and behavior. The review also revealed current studies regarding dynamic or tunable lighting that adjusts CCT based on desired activity and mood. Data from an original survey analyzed teacher insights and perceptions regarding student attitudes and behaviors associated with existing classroom lighting and the impact of higher color temperature LED. Methods: Participants were pre-K through high school qualified teachers from three schools and/or personal contacts of the principal investigator. Seventy-five teachers responded to the online questionnaire. The survey data suggests teachers perceive higher color temperature lighting positively impacts student alertness, attitude, and energy level; and adjusting light levels throughout a school day positively impacts student engagement. Results and conclusion: Results supported the perception of higher correlated color temperature lighting positively impacting alertness, attitude, and energy level. Findings also supported the ability to change light levels throughout the school day to positively impact student engagement and mood. There were mixed results regarding higher correlated color temperature impacting attention and on-task/off-task behaviors. Results regarding the impact of sound and flickering from fluorescent lights were not significant.

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Section: Fluorescent Led and Correlated Color Temperature Overviewmentioning

confidence: 99%

“…Reducing energy output is an important factor for both environmental and economic reasons though some studies have found that energy savings was small due to high parasitic losses [11]. Thus, lighting technology needs to be evaluated on its benefits and expectations beyond/in addition to reduction of energy supply and costs.…”

Section: Behavioral Categoriesmentioning

confidence: 99%

The impact of fluorescent and led lighting on students attitudes and behavior in the classroom

Morrow¹,

Kanakri²

2018

apr

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“…The inconsistent findings of earlier studies indicate that the impacts of light highly depend on the research design, including the intensity, timing, and duration of the light exposure. Recently, the use of light-emitting diode (LED) has continued to increase owing to the low energy consumption and governmental regulations 32,33 . The growth is powered by the IoT integrated into LED-based luminaires, which is also called smart lighting 34 .…”

Section: Introductionmentioning

confidence: 99%

Awakening effects of blue-enriched morning light exposure on university students’ physiological and subjective responses

Choi

Shin

Kim

et al. 2019

Sci Rep

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We investigated physiological and subjective responses to morning light exposure of commercially available LED lighting with different correlated colour temperatures to predict how LED-based smart lighting employed in future learning environments will impact students. The classical markers of the circadian system (melatonin and cortisol), as well as the subjective perception of sleepiness, mood, and visual comfort, were compared. Fifteen university students underwent an hour of morning light exposure to both warm (3,500 K) and blue-enriched (6,500 K) white lights at recommended illuminance levels for classrooms and lecture halls (500 lux). The decline of melatonin levels was significantly greater after the exposure to blue-enriched white light. Exposure to blue-enriched white light significantly improved subjective perception of alertness, mood, and visual comfort. With regard to cortisol, we did not find a significant difference in the cortisol decrement between the two light conditions. Our findings suggest that the sensitivity of physiological and subjective responses to white LED light is blue-shifted. These findings, extending the already known effects of short-wavelength light on human physiology, reveal interesting practical implications. Blue-enriched LED light seems to be a simple yet effective potential countermeasure for morning drowsiness and dozing off in class, particularly in schools with insufficient daylight.

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“…In this application, multiple LED devices generally form an intelligent lighting system through a network, and the LED devices can usually be remotely controlled. In addition to road lighting for large-scale applications [1][2][3][4], most of these smart LED lighting systems are often used indoors or outdoors, and the scale is small [5][6][7]. Figure 1 shows a case for a small-scale LED smart lighting system, such as for commercial lighting, home lighting, landscape lighting, wall washers, high pole lights, etc.…”

Section: Introductionmentioning

confidence: 99%

New DC Grid Power Line Communication Technology Used in Networked LED Driver

Lin

Hu²,

Zhou

et al. 2018

Energies

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In order to reduce the cost and improve the reliability, real-time performance, and installation convenience of remote-controlled light-emitting diode (LED) lighting systems, a networked LED driving technology based on the direct current (DC) grid power line carrier is proposed. In this system, an alternating current (AC)/DC bus converter converts the mains into a DC bus with multiple distributed LED drive powers on the DC bus. The AC/DC bus converter receives the user’s control command and modulates it into the DC bus voltage. The DC bus waveform changes to a square wave containing the high and low changes of the address information and command information. The LED drive power of the corresponding address receives energy from the DC bus and demodulates the commands, such as turning the lights on and off, dimming, etc., and performs the action. In order to make the waveform of the AC/DC bus converter have better rising and falling edge, this paper adopts the half-bridge topology with variable modal control. In the modulation process, the circuit works in buck mode and boost mode. Distributed LED drivers have DC/DC circuits and very simple demodulation circuits that dissipate energy and information from the DC bus. Through experiments, the technology not only simplifies the use of communication technology in application, but also reduces the application difficulty.

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A field study of fluorescent and LED classroom lighting

Cited by 40 publications

References 25 publications

The impact of fluorescent and led lighting on students attitudes and behavior in the classroom

The impact of fluorescent and led lighting on students attitudes and behavior in the classroom

Awakening effects of blue-enriched morning light exposure on university students’ physiological and subjective responses

New DC Grid Power Line Communication Technology Used in Networked LED Driver

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