Lighting the Computerized Office: A Comparative Study of Parabolic and Lensed-Indirect Office Lighting Systems

1989 ◽  
Vol 33 (8) ◽  
pp. 521-525 ◽  
Author(s):  
Alan Hedge ◽  
William Sims ◽  
Frank Becker

A comparative field survey of the effects of two alternative lighting systems, a parabolic downlighting system and a ceiling suspended, lensed- indirect lighting system, on computer workers in a virtually windowless office was conducted. A questionnaire, collecting data on work content, perception of ambient environmental conditions including office lighting, work-related health symptoms, job stress and job satisfaction, and self-reported productivity was completed by 96 workers. Results show that the lensed-indirect lighting system was rated significantly more favorably on several subjective lighting quality scales, and significantly more appropriate for computer based work. Workers reported less problems with glare on their computer screen and with work being hindered, fewer eye problems (tired eyes, trouble focusing eyes), better productivity, and significantly higher satisfaction for the lensed-indirect system compared with parabolic lighting.

2019 ◽  
pp. 15-21
Author(s):  
Banu Manav

In lighting design, the main concept is to achieve a healthy environment, which addresses energy efficiency, cost, maintenance, and quality. User-friendly lighting systems shall be adopted to architecture and interior architecture. User control over the lighting system is important, by dimming or increasing light output, by changing the colour of the light sets the inner atmosphere and affects user mood. Standards and codes on lighting shall also be evaluated by means of these topics. The paper aims to analyse how the luminous environment is affective on the perceived environment. Hence, a series of experimental studies and recent research will be evaluated in regard to understanding and designing luminous environment.


Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 202
Author(s):  
Gianluca Serale ◽  
Luca Gnoli ◽  
Emanuele Giraudo ◽  
Enrico Fabrizio

Artificial lighting systems are used in commercial greenhouses to ensure year-round yields. Current Light Emitting Diode (LED) technologies improved the system efficiency. Nevertheless, having artificial lighting systems extended for hectares with power densities over 50W/m2 causes energy and power demand of greenhouses to be really significant. The present paper introduces an innovative supervisory and predictive control strategy to optimize the energy performance of the artificial lights of greenhouses. The controller has been implemented in a multi-span plastic greenhouse located in North Italy. The proposed control strategy has been tested on a greenhouse of 1 hectare with a lighting system with a nominal power density of 50 Wm−2 requiring an overall power supply of 1 MW for a period of 80 days. The results have been compared with the data coming from another greenhouse of 1 hectare in the same conditions implementing a state-of-the-art strategy for artificial lighting control. Results outlines that potential 19.4% cost savings are achievable. Moreover, the algorithm can be used to transform the greenhouse in a viable source of energy flexibility for grid reliability.


2016 ◽  
Vol 50 (4) ◽  
pp. 631-650 ◽  
Author(s):  
N Gentile ◽  
T Goven ◽  
T Laike ◽  
K Sjoberg

Indoor lighting is facing a massive retrofit to LED lighting. Research is needed to assess whether LED-based lighting can promote energy efficiency, boost visual comfort and support biological functions. This field study considered the lighting of four identical classrooms in an upper secondary school in Helsingborg, Sweden. Two classrooms were fitted with state-of-the-art ceiling pendants containing T5 fluorescent tubes and that had a direct/indirect light distribution (the control rooms). The other two classrooms were fitted with an experimental LED indirect lighting system (the experimental rooms). In the classrooms, 72 students aged 17–18 years performed their usual educational activities over a whole academic year. The light environment, electricity consumption, and students’ mood, light perception and saliva cortisol concentration were monitored. The two lighting systems produced only marginal differences. Overall, the experimental rooms were slightly preferred but achieved only small energy savings due to high parasitic losses.


2021 ◽  
Vol 13 (13) ◽  
pp. 7109
Author(s):  
Gabriela Dima ◽  
Luiza Meseșan Schmitz ◽  
Marinela-Cristina Șimon

This paper aimed to explore the changes posed by the new COVID-19 pandemic to the field of social work and its impact on social workers in terms of job stress and burnout in Romania. Two conceptual models were used to frame the discussion: the theoretical framework of VUCA (volatility, uncertainty, complexity, and ambiguity) to discuss the challenges that the unprecedented context of the COVID-19 pandemic has created for social workers; and the Job Demands and Resources model (JD-R) to understand job demands perceived as stressors and burnout. Based on convergent mixed methods, the study sample consisted of 83 social workers employed in statutory and private social services in Romania, from different areas of intervention. Results showed that social workers perceived a high level of job stress related to work during the pandemic, which was associated with higher levels of burnout in the areas of personal burnout (average score 55.9) and work-related burnout (average score 52.5). Client-related burnout was lower (average score 38.4), indicating that stress was generated mainly by organisational factors and work-related factors (workload, aligning to new legislative rules and decisions, inconsistency, instability, ambiguity of managerial decisions, and lack of clarity of working procedures) and less by client-related stressors (lack of direct contact with clients, risk of contamination, managing beneficiaries’ fears, and difficulties related to technology). High job demands and limited job resources (managerial and supervisory support, financial resources, and recognition and reward) led to a high to very high level of work-related burnout for 15.7% and an upper-medium level for 44.2% of respondents. A group of 27.7% reported lower to medium levels of work-related burnout, while 14.5% had very low levels, managing to handle stress factors in a healthy manner. Study results pointed to the importance of organisational support and the development of a self-care plan that help to protect against job stress and burnout. Recommendations were made, putting forward the voice of fieldworkers and managers fostering initiatives and the application of sustainability-based measures and activities designed to deal with the challenges of the VUCA environment.


2012 ◽  
Vol 13 (4) ◽  
pp. 191-199
Author(s):  
Karen J. Buhr

BACKGROUND: Nurses’ occupational stress and job satisfaction can have an affect on lifestyle choices and productivity. OBJECTIVES: The objective of this study is to provide a detailed examination of the relationship between job satisfaction, job stress, unhealthy lifestyle choices, and productivity among Canadian nurses. METHODS: This study uses data from the confidential master data files of the 2005 National Survey of the Work and Health of Nurses (NSWHN). Ordinary least squares regressions and binary probit regression models were used to estimate the relationships between job satisfaction and job stress on productivity and unhealthy lifestyle choices. RESULTS: Workplace stress variables have a small effect on lifestyle choices. Job satisfaction has an effect on the probability of smoking, but not on drinking. Workplace stress and job satisfaction do not have statistically significant effects on productivity. DISCUSSION: The study found weak relationships among the work related stress variables and productivity. These findings can allow policy makers to consider efforts to reduce workplace stress which can be beneficial to productivity.


2019 ◽  
Vol 2 (2) ◽  
pp. 42
Author(s):  
R. Febriyursandi ◽  
A.Z. Azryenni ◽  
A. Hamzah

This research develops and implements methods for calculating lighting systems for classrooms in the Khairul Ummah Boarding School. The lumen is used to determine the number of luminaires needed to improve lighting quality following SNI 6197:2011. The number of luminaires obtained from this study was entered into the DIALux Evo 8.1 software. The results obtained of this study indicate that the lighting in the classroom at Khairul Ummah Boarding School didn’t reach the recommended standard, the direct measurement results of the average lighting level of class A was 10.79 lux, while the class X-IPA-3 was 11.66 lux. To improve this condition, class A requires 15 luminaires, and X-IPA-3 requires 12 luminaires. The difference in the results obtained from the two calculations for class A is 0.6%, and X-IPA-3 is 3.4%. Investment costs are needed to improve the lighting system in these classes worth Rp.2,700,000.00 to provide 27 lamps.


2021 ◽  
Vol 40 (1) ◽  
pp. 49-55
Author(s):  
A.M. Usman ◽  
Y.A. Adediran ◽  
A.O. Otuoze ◽  
O.O. Mohammed ◽  
O.S. Zakariyya

Replacing failed bulbs of streetlights in a location can be very tasking and expensive if the optimal time for replacement is not determined. In this paper, a model has been developed that helps to establish the optimal time for the replacement of streetlight bulbs. Burnt-out bulbs are replaced individually when they fail, and group replacement is carried out on all bulbs after a specified time. The costs for both individual replacement and group replacement are determined. The developed model was applied to locally sourced data from a field survey of a streetlight installation at the University of Ilorin, Ilorin, North-central Nigeria. The model gave the optimum replacement time of burnt-out bulbs as the eighteenth week when applied to the data used in this work. The optimum replacement time will be dependent on the dataset used. This makes the developed model useful in establishing the optimal replacement time of any stochastically failing items that are in large quantities. The model will help to reduce maintenance costs for facility managers.


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