* Incandescent lamps (light bulbs)generate light by passing electric current through a resistive filament, thereby heating the filament to a very high temperature so that it glows & emits visible light. A broad range of visible frequencies are naturally produced, yielding a "warm" yellow or white color quality. Incandescent light is highly inefficient, as about 98% of the energy input is emitted as heat. A 100 W light bulb emits about 1,700 lumens, about 17 lumens/W. Incandescent lamps are comparatively cheap to make. The typical lifespan of an AC incandescent lamp is around 1,000 hours. They work well with dimmers. Most older lighting fixtures are designed for the size & shape of these traditional bulbs.
* Fluorescent lamps (light bulbs)work by passing electricity through mercury vapor, which in turn emits ultraviolet light. The ultraviolet light is then absorbed by a phosphor coating inside the lamp, causing it to glow, or fluoresce. While the heat generated by a fluorescent lamp is much less than its incandescent counterpart, energy is still lost in generating the ultraviolet light & converting this light in to visible light. If the lamp breaks, exposure to mercury can occur. Linear fluorescent lamps are usually four to four times the cost of equivalent incandescent lamps but have life spans around 10,000 & 20,000 hours. Lifetime varies from 1,200 hours to 20,000 hours for compact fluorescent lamps. Most fluorescent lamps are not compatible with dimmers. Those with "iron" ballasts flicker at 100 or 120 Hz, & are less efficient. The latest T8-sized triphosphate fluorescent lamps made by Osram, Philips, Crompton & others have a life expectancy greater than 50,000 hours, if coupled with a warm-start electronic ballast. The life expectancy depends on the number of on/off cycles, & is lower if the light is cycled often. The efficiency of these new lamps approaches 100 lumens/W. The efficiency of fluorescent tubes with modern electronic ballasts & compact fluorescents often ranges from 50 to 67 lumens/W. Most compact fluorescents rated at 13 W or more with integral electronic ballasts accomplish about 60 lumens/W, comparable to the LED bulb.
LED | FLUORESCENT (CFL) | INCANDESCENT | |
Life Span (How long will the light bulb last?) | 60,000 hours | 10,000 hours | 1,200 hours |
Watts Per Bulb (Wattage Equiv. at 60w) | 6 | 14 | 60 |
Cost Per Bulb | $15.98 | $2.98 | $1.25 |
KWh of electricity used over 60k hours | 360 | 840 | 3,600 |
Electricity Cost ( @$0.20 per KWh ) | $72.00 | $168.00 | $720.00 |
Bulbs needed for 60k of usage | 1 | 6 | 50 |
Equivalent 60k hour Bulb expense | $15.98 | $17.88 | $62.50 |
Total cost for 60k hours | $87.98 | $185.88 | $782.50 |
| |||
Total cost for 30 bulbs | $2,639.40 | $5,576.40 | $23,475.00 |
Savings by Switching from Incandescent | $20,835.60 | $17,898.60 | 0 |
Information on LED Lighting Products
Ecology and Environment | Very Friendly/Min. Issue | Damaging-Mercury/Argon | Damaging |
Heat Issue | Least | Ballast Heat | Largest |
Light Control | Most Control | Least Control | Variable Control |
Maintenance | Zero | Ballast Issue | Replacement |
Weather Temperature Changes | Not Sensitive | Sensitive | Some Sensitive |
Effective Lumens | Equivalent | Equivalent | Equivalent |
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