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Lighting

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Saved by PBworks
on October 1, 2007 at 2:04:35 pm
 

Lighting

 

The Navy has some background data from 2002 (also linked from Data) that shows Low Pressure Sodium generating well over 100 lumens / watt (183 for the biggest lamps). Lumens is the standard measure of the amount of light emitted from a bulb. Watts are what we pay for and incandescent lights consume a lot of watts (e.g. 100W) to make not so many lumens (e.g. 1700 or 17 lumens/watt). More lumens / watt is better so here are some better-than-incandescent options.

 

CFLs (~75 lumens/watt)

Sources & Advice

 

Disposal

  • EPA fact sheet
  • many lighting and hardware stores accept fluorescent bulbs for safe disposal
  • lamprecyle.org has a state-by-state recycling contacts map

 

Analysis

 

Must [...] Identify the light color. (Qualified bulbs are available in designated correlated color temperatures (CCT): 2700K (warm white), 3000K (soft white), 3500K (white), 4100K (cool white), 5000K (natural), or 6500K (daylight). Provide a color rendering index (CRI) of 80 or more. Incandescent light bulbs have a CRI close to 100. (Learn about color rendering index and correlated color temperature.)

 

  • thebulb.com's about page includes an explanation of color temperature:

 

Color Temperature

The color temperature of a light bulb can best be described as how the light compares to “natural” sunlight. Outdoor sunlight has a color temperature of around 5,500K. Bulbs with a higher color temperature (closer to 5,000K) will produce light that is more “cool” or blue. Bulbs with a lower color temperature will produce light that is more “warm” or yellow. The color temperature of a light bulb is usually described by how “white” a bulb is, like soft white, bright white, etc.

Description Color Temperature
“Warm white” or “Soft white” < 2700 K
“White”, “Bright White”, or “Medium White” 2900 - 3000 K
“Cool white” 4000 K
“Daylight” > 5000 K

Source: http://www.thebulb.com/store/t-compact-fluorescent-light-bulbs.aspx

 

LEDs

 

The GS6 LED downlight has a system efficacy of up to 35 lumens per watt, which is comparable(??) to compact fluorescent downlights, and more than three times the efficacy of a bare 65W incandescent reflector lamp.

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