| Overview | | | | replaced much less frequently. LEDs use about half |
| Environmentally friendly options for replacing | | | | the amount of electricity that CFLs that output the |
| incandescent lighting are usually either Compact | | | | same brightness use. |
| Fluorescent Lamps (CFL) or Light Emitting Diode (LED) | | | | Long Lifespan: |
| bulbs. | | | | Run-times of CFL bulbs typically range from 6,000 |
| Compact Fluorescent Lamps | | | | hours to 15,000 hours while the typical lifespan of an |
| CFLs operate similarly to conventional fluorescent | | | | incandescent lamp is around 1,000 hours. A LED lamp |
| lamps where electricity is used to activate mercury | | | | can last 50,000 to 60,000 hours which equates to |
| vapor that resides in the glass tube. The current | | | | around 5 or 6 years (10 times longer than a CFL). |
| affects the mercury atoms to make ultraviolet (UV) | | | | High quality light output: |
| light which is not visible to the eye. The photons from | | | | Both CFL and LED bulbs can now provide a range of |
| the ultraviolet light hit a phosphor layer inside the bulb | | | | color temperatures. Consumers are no longer |
| housing to emit photons of visible light thereby creating | | | | restricted to the blueish, "cool-white", of earlier bulbs, |
| light output from the tube. The ultraviolet light may | | | | and can now buy warmer colored lamps. Lower |
| cause fading in paintings or textiles. The mercury | | | | quality CFL bulbs that use a magnetic ballast will flicker. |
| contained within the lamp means that the light bulbs | | | | Look for an electronic ballast when buying a CFL. |
| need to be properly disposed of as compact | | | | LEDs are driven so that they don't flicker. |
| fluorescent bulbs dumped in landfills burst, causing | | | | Versatility: |
| mercury to be released, draining into the ground, | | | | Indoor, outdoor, home, or commercial LED and CFL |
| ultimately contaminating the food chain. Some states, | | | | bulbs can be used in a many different types of |
| such as California, ban the disposal of | | | | applications where conventional bulbs were once used. |
| mercury-containing bulbs in the trash. Some state laws | | | | LED bulbs and CFLs can be used in track lighting, table |
| require fluorescent bulbs to be collected as hazardous | | | | lamps, task lighting, recessed fixtures, and ceiling |
| waste or properly recycled. Check with the EPA site | | | | fixtures. Both types of bulbs are available in dimmable |
| to help you with proper disposal procedures according | | | | models for use with a standard dimmer switch. |
| to your state, or you can find a recycling center near | | | | Durability: |
| you at Earth911. | | | | Since LED light bulbs don't use a filament like |
| Unlike fluorescent tubes that don't contain circuitry, | | | | incandescent, they are shock resistant and can be |
| compact fluorescent usually integrate all of the | | | | used in high vibration applications. |
| necessary circuits in the bottom of the light allowing the | | | | Summary of Drawbacks and Limitations |
| single unit to be used in a standard incandescent light | | | | CFLs: |
| bulb socket. CFLs come in a variety of styles and | | | | No spot lights - Since CFLs don't project a focused |
| shapes, but one will often see them in a tube or spiral | | | | beam like an LED bulb, they are best used for area |
| option. Higher surface area allows for a higher light | | | | lighting. |
| output in CFLs. | | | | Temperature sensitivity - CFLs are sensitive to heat, |
| LED Lighting | | | | their lifetime will be reduced if the fixture does not |
| Solid-state lighting, more commonly known as LED | | | | properly dissipate heat. CFLs are also affected by |
| (light-emitting diode) lighting is a solid semiconductor light | | | | cold. CFLs will take considerably longer to reach full |
| source that doesn't use a gas tube like that of the | | | | brightness in cold weather. In extreme situations they |
| CFL. Light from an LED is made when electricity is | | | | may not properly warm up. |
| applied through the semi-conductor doped with | | | | Warm-up time - LED lights turn on instantly, while CFLs |
| impurities to create one half which is a "p-side", and | | | | take a few minutes to warm up and provide full |
| another half that forms the "n-side". The | | | | brightness. |
| charge-carriers (electrons and holes) flow into the p-n | | | | Hazardous waste - CFLs contain mercury and must |
| junction where these two halves meet, and releases | | | | be properly disposed of. The EPA website provides |
| energy in the form of a photon, thereby creating light. | | | | proper disposal options. LEDs do not contain mercury. |
| The color of the light output depends on the materials | | | | Frequent Cycling Lowers Lifespan - In high traffic |
| forming the p-n junction. There is no filament to burn | | | | areas, such as home bathrooms, where CFLs are |
| out, and unlike CFLs, LED lights do not contain the toxic | | | | turned on and off often, their lifespan will decrease |
| mercury, nor do they emit ultraviolet light. | | | | quickly. |
| To get a bright output, many older models of LED light | | | | Ultraviolet Light - CFL bulbs can emit UV-light which |
| bulbs had resorted to clustering many individual LEDs | | | | may not be desirable for certain applications. |
| into a one housing, however many of the newer LED | | | | LEDs: |
| bulbs drive a single high powered LED element. These | | | | High initial cost - The LED bulbs themselves are costly, |
| LED light bulbs are considerably smaller than their CFL | | | | but the initial investment is quickly recuperated in lower |
| counterparts, and are offered in form factors that | | | | electricity bills. |
| produce a directional beam through the use of a glass | | | | Heat generation - Certain high power (5w and up) LED |
| or plastic lens, or encased behind a frosted diffuser to | | | | light bulbs may produce significant heat. Heat-sinks are |
| provide wider light coverage. | | | | often built into the bulbs themselves, and may require |
| Summary of Benefits | | | | LED specific fixtures to ensure proper air-flow. |
| Less Expensive Electricity Bill: | | | | LED light bulbs are becoming the choice for energy |
| Although the cost of the light bulbs are initially more | | | | efficient lighting due to their varied bulb options, and the |
| expensive, both CFL and LED lamps save you money | | | | ease of which the light output can be layered and |
| long run. Less electricity is used, and bulbs are being | | | | controlled when compared with CFL bulbs. |