Bright Ideas Ergonomic considerations for lighting the modern office

1. Bright Ideas Ergonomic considerations for lighting the modern office Jonathan Puleio, M.Sc. CPE Director of Consulting Humanscale Corporation Rudy Szollar Chief, New Business Development UNICOR May 2012

2. Value to the Customer • Value: To educate the customer as to the important concerns involved in designing lighting the modern workplace. Example: Happy, healthy workers are more productive. They take less time off and perpetuate a harmonious work environment. • Value: How happy, healthy workers can add to the efficiency of the agency and gives better service to the taxpayers. Example: In a better work environment, workers bring a positive attitude ands can-do spirit that translates into superior results.

3. Take a close look and discover UNICOR… We’re structured for your success. Known officially as Federal Prison Industries, Inc. (FPI), UNICOR was established in1934 by Executive Order, with a mission to rebuild the lives of individuals who have taken wrong turns in life. UNICOR’s program provides federal inmates valuable job and life skills which, upon release from prison, will enhance their prospects for employment and success within our communities. UNICOR is an incredible investment in developing the human potential. Its nationwide infrastructure offers… • More than 175 products and services to the Federal Government and beyond. • Hassle-free purchasing. If we meet your needs, there’s no need to compete your requirement. • Green, inside and out. From raw materials and manufacturing processes to end products, packaging and shipment. • Integrity you expect. UNICOR adhears to a strict code of ethics and incorporates only the highest standards of business practices. • Made in America. Quality, made in the USA products supporting domestic jobs and our nation’s economy.

4. With your UNICOR purchase, you make an invaluable investment in developing the human potential, leading to residual, lasting benefits; a reduction in government spending; positive impact upon the U.S. economy; the viability and health of our communities; the safety and security of our nation’s correctional facilities. It’s a win-win solution. You can make a difference. UNICOR has a positive impact upon the U.S. economy while providing a fresh start for a brighter future!

5. OPENING remarks Single source lighting schemes are no longer appropriate for accommodating the needs of today’s computer users Implications of poor lighting schemes range from energy waste to reduction in human comfort and performance An obvious conflict exists between the lighting requirements for computer use and paper-based work

6. LIGHTING STANDARDS60s-70s • General office lighting ranged from 100-150 fc • Employees worked mostly with paper based documents • Exclusive use of fluorescent overhead lighting provided little flexibility • Widespread usage of task lighting

7. LIGHTING STANDARDS80s-90s • Ambient light levels lowered to 75-100 fc • Introduction of personal computers • Task lighting cut from most interiors projects • Screen glare cited as number one complaint among computer users

8. LIGHTING STANDARDS2000s-today • Ambient light levels lowered to 40-50 fc • Widespread computer use • Indirect lighting grows in popularity • Paper-based work less prevalent than before

9. LIGHTINGand visual discomfort

10. EMPLOYEE PERCEPTIONSof existing lighting schemes • The American Society of Interior Designers found that 68% of employees complain about the light in their offices. • 38% of workers reported that their lighting was too bright or too dim • 79% of computer users want to control their light levels • 75% report they could be more efficient and productive with better lighting

11. HUMAN IMPACTof poor lighting schemes • 30% suffer from headaches • 25% report losing 15 minutes or more per day due to eye focusing problems (equivalent to 1.5 weeks per year!) • 80% experience glare

12. HUMAN IMPACT of poor lighting schemes Computer Vision Syndrome (CVS): A condition that results from focusing the eyes on a computer display for uninterrupted periods of time. Symptoms: • Headaches • Blurred vision • Neck pain • Fatigue • Eye strain 90% of computer users experience Computer Vision Syndrome (CVS)

13. CURRENT CHALLENGES in office lighting Aging workforce Monitor/document conflict Over-illumination Glare Shadows Screen flicker

14. PRESBYOPIA ‘farsightedness’ • With age, our eyes change • The corneal lens hardens and • develops opacities • The ciliary muscles that control • the lens atrophy with age • The process of accommodation • becomes increasingly difficult • Near field viewing requires • correction

15. CONTRAST REQUIREMENTS as a function of age • The need for task lighting increases with age • Persons ages 61-70 require more than 250% more contrast than persons ages 20-30 • Illumination requirements differ significantly between employees Relative Contrast Required as a Function of Age 400 350 300 250 Relative Contrast Required 200 150 100 50 0 20-30 31-40 41-50 51-60 61-70 Age

16. CONTRAST REQUIREMENTS as a function of age Contrast requirements increase exponentially after age 40. 20 Years 60 Years 75 Years

17. MONITOR/DOCUMENT conflict • Monitors generate light, whereas paper reflects light • Paper-based documents requires 4-5 time more light than does viewing a monitor

18. OVER ILLUMINATION of computer work environments • Visual symptoms increase when over-head light levels exceed 25 fc • Light levels above 25 fc should be positioned between the user’s eyes and the task • The current IES standards were developed before widespread computer use

19. OVER ILLUMINATION of computer work environments • Monitor hoods are designed to reduce screen glare – might there be a more obvious solution? • Some workers actually respond to over-lit spaces by wearing visors • The presence of this equipment suggests there is an underlying problem

20. COMPUTER MONITORS emit light

21. RECOMMENDED illumination levels vary by task Source: Illuminating Engineering Society

22. SOURCES of visual discomfort: Glare • Direct Glare • Natural light, overhead light fixtures, under cabinet lighting • Reflected Glare • Work surface, computer screen Presence of glare is linked to a 3% decrease in visual task efficiency Source:Osterhaus, W.K.E., Bailley, I.L., Proceedings of the IEE Industry Applications Society Annual Meeting, 1992

23. SOURCES of visual discomfort: Shadows • Multiple shadows and blurred images can cause focusing issues and eye strain

24. SOURCES of visual discomfort: Screen Flicker • A Cornell University study on VDT users found: • Blink rate diminished by 1/3 • Reading speed was 8 times slower compared with paper based documents

25. LIGHTING and task performance

26. LIGHTING and task performance Illumination levels Contrast ratios Color Rendering Index (CRI) Color temperature

27. ILLUMINATION and task performance • Task performance increases as illumination increases • Proper light level is moderated by age, duration and task Bennet, C., Chitlangia, A., and Pangrekar, A. (1977). Illumination levels and performance of practical visual tasks. Proceedings of the Human Factors Society 21st Annual Meeting. pp. 322-325

28. FIELD STUDY on light level and task performance • A 2010 study in an outpatient pharmacy measured accuracy rates under two lighting conditions: • At 45 fc, error rate was 3.8% • At 146 fc, error rate was 2.6%, a 46% increase in accuracy Source: Buchanan, et al., Am J Hosp Pharm 48(10): 2137.

29. ILLUMINATION & CONTRAST and task performance • Data entry speed increases as illumination increases • Data entry speed increases as contrast increases Source: Boyce, P. (2003). Human factors in lighting. 2nd edition, New York: Taylor & Francis

30. COLOR rendering index (CRI) • CRI describes how accurately artificial lights render colored surfaces. It is measured on a scale of 1-100 with 100 being natural daylight. • CRI of 76 or above is excellent • CRI of 60-76 is good • CRI below 60 is poor • CRI greater than 90 is needed for color matching tacks Excellent CRI Poor CRI

31. COLOR rendering index (CRI) • CRI is a good indicator of expected performance in color judgment tasks • As the CRI increases, color judgment errors decrease Source: Boyce, P. (1981). Human factors in lighting. New York: Macmillan

32. COLOR temperature & visual acuity • The higher the color temperature, the cooler the appearance of the bulb. • Bulbs which exceed 5000K have been linked to improved visual acuity and are ideal for task lighting • Warmer, lower color temperatures are preferred for ambient lighting

33. COLOR temperature & visual acuity • Warm color temperature • Comfortable, yet not ideal for reading paper documents requiring high levels of visual acuity • Ideal for computer based work

34. COLOR temperature & visual acuity • Cool color temperature • Less comfortable • Better for reading paper based documents

35. COLOR temperature & visual acuity • Ideal compromise • Warm ambient lighting combined with cool task lighting • Optimized color temperatures for computer use and for paper based work

36. DUAL Component Lighting Schemes

37. DUAL COMPONENT lighting schemes provide individual control • Single component: • Too much light above eyes • High energy waste • Dual component: • Light level determined by user • 30-40% less energy required

38. DUAL COMPONENT lighting schemes provide individual control Illumination levels are dictated by the distance between the luminaire and the work surface

39. GUIDELINES for positioning a task light • A task light should be positioned opposite the worker’s writing hand to minimize shadows • Direct the light such that it sweeps across the viewing area • Minimize direct glare by angling the shade light away from the worker’s eyes

40. RECONSIDER THE USE OF under-cabinet-lighting • Under-Cabinet-Lighting: • Provides lighting away from where the tasks are actually occurring! • Does not offer individual control of illumination level • Is less energy efficient than most controllable task lights

41. RECONSIDER THE USE OF under-cabinet-lighting Potential source of glare Light is away from where work is occurring

42. TASK LIGHTING research

43. RESEARCH on individual control • A laboratory study at RPI’s Lighting Research Center found that subjects who had controllable lighting: • Felt more comfortable in the room • Rated the tasks as being less difficult • Rated the lighting quality as higher than subjects who did not have control • Produced a 35% to 42% decrease in energy consumption Source: Veitch, J., ‘Individual control can be energy efficient’ International Association for Energy Efficient Lighting, 8(22), 1999

44. RESEARCH on energy consumption • Dual component lighting schemes can reduce energy consumption by two thirds compared to conventional lighting systems • Ambient illumination levels can be decreased while task illumination levels can be increased Source: Akashi Y, Mukal K, Yanabe Y. A task and ambient lighting system providing energy efficient savings without decreasing the overall brightness impression

45. ENERGY IMPLICATIONSof improved lighting technologies • In CA alone, lighting accounts for 23% of the total energy used in the State • The EPA has found that lighting for industry, office, warehouses, and stores accounts for 80-90% of the total lighting energy used in the US • Reducing lighting energy by 50% would reduce aggregate national energy demand by 10%

46. TASK LIGHTINGand LEED Certification Incorporating task lights into an office lighting scheme can contribute toward achieving LEED credits in the following areas: • Energy & Atmosphere • Materials & Resources • Indoor Environmental Quality • LEED CI ID Credit 1.x

47. KEY POINTSto remember • Most modern offices are over-lit at tremendous energy waste and human detriment • Proper light levels vary significantly with worker age and task. • Dual component lighting schemes can positively impact comfort and human performance while lowering energy consumption 30-40% • As designers and architects, you can have a measurable impact!

48. ERGONOMIC RESOURCES www.unicor.gov http://ergo.human.cornell.edu http://www.lrc.rpi.edu www.humanscale.com

49. Rudy Szollar E-mail: rszollar@central.unicor.gov Phone: 202-305-3902