Electric Lighting Sources: The Lamps Understand lamps and fixtures Lamp Issues Efficacy Efficiency in Lumens/Watt Lumens Total output Life Hours of use Color How objects look Health The effect on users Efficacy varies with lamp type 1
and among lamp types LED efficacy varies from 13 to 61 l/w for lamps up to 25 watts LED Replacement Lamps drivers cause waste heat generation 2
bottom line is w/sqft and remember, dimming reduces watts/square foot Lumens output varies with lamp type For a 400 watt lamp Incandescent 7,000 lumens Mercury Vapor 20,000 lumens Fluorescent 31,000 lumens High Pressure Sodium 42,000 lumens Light-Emitting Diodes unknown 3
Life expectancy varies with lamp type Incandescent 100w 750 hours (long life = 2500 hrs) Mercury Vapor 75w 16,000 hours Fluorescent 40w 20,000 hours High Pressure Sodium 100w 20,000 hours Light-Emitting Diode 24w 35,000 hours Color varies with lamp type and within lamp type and we compare it to the color of daylight Daylight MIT model w/north light Seattle LDL demo south light through different glazing types Grey T=.14 Blue T=.87 Grey T=.45 Bronze T=.21 Bronze T=.54 4
Incandescent lamps smooth curve, red bias remember our eyes are most sensitive to (offended by) light at wave length of 550 nanometers MIT model w/incandescents Arby s Moscow Warm White Fluorescent MIT Model w/warm white fluorescent 5
Cool White Fluorescent AAN w/cool white w/daylight fluorescent Mercury Vapor vs. Metal Halide 6
High Pressure Sodium HP Sodium vs. Daylight Fluorescent UI Memorial Gym LEDs vs. High-Pressure Sodium 7
RGB LEDs allow color tuning from your smart phone. 8
How to rate color rendering Gamit Area Index see lrd.rpi.edu/assist Color Quality Scale see nist.gov/pml/div685/grp05/vision_colorcfm 9
Lighting affects health and mood, ultimately productivity Why light therapy offers an opportunity to cope with the problems of a modern, 24-hour society --S.H.A. Begemann Breakthrough Separate non-visual detection of light Curative Applications Winter depression and blues Treat jet lag and shift work symptoms Preventative Applications Reduce absenteeism & increase productivity Treat symptoms in home-bound elderly Disclaimer Most promising for office and elderly Light & Health 2002 Eindhoven University 20 November 2002 Light and Performance --Gerard Kerkhof In addition to its effect on the timing of circadian rhythms blue light exposure can result in melatonin suppression, elevation of body temperature, and also increases in alertness and improvements in performance. Light & Health 2002 Eindhoven University 20 November 2002 10
In light treatment for SAD and non-seasonal depression, some degree of improvement occurs within the first hour (although full treatment may take several weeks. In light treatment for SAD and non-seasonal depression, light in the blue end of the spectrum has proven to be most effective... Application of Healthy Lighting in the Workplace --Laurens Zonneveldt What is healthy office lighting? ~1000 lux needed for psycho-biological stimulation traditional lighting design illuminate the task avoid glare biological lighting design consider light falling on eye Light & Health 2002 Eindhoven University 20 November 2002 11
In the daytime, performance and well-being --Marc Fontoynout Daytime daylight is the economical light source that offer illuminances above 2000 lux with ideal spectral distribution Preferred light at work Survey respondents choice For human health more than energy savings Cost equal to 1 hour s work/person/year Light & Health 2002 Eindhoven University 20 November 2002 Application of Healthy Lighting in the Home Tunable for Health & Welfare Application of Healthy Lighting in the Home Use light shower? Tunable for Mood 12
Consideration for Healthy Lighting for Multiple Species Humans Hampsters Dogs Birds Plants Black indicates colors not sensed to be continued 13