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  • Wuxi Kinglux Glass Lens Co.Ltd
  • ADD:No.286,Changjiang North Rd,New Dist,Wuxi,JS prov,China
  • Tel: 86-510-66759801
  • Fax: 86-510-84602998
  • Mobile phone: 86-18168862789
  • E-mail: ledglasslens@163.com
  • Contact person: Huimin Zhang
  • Incandescent Lighting vs Light Emitting Diode (LED) Comparison
    May 07, 2018

    Topic

    LED Notes

    Incandescent Notes

    Winner

    Correlated Color Temperature (read more here)

    LEDs are available in a wide range of color temperatures that generally span from 2200K-6000K (ranging from “warm” yellow to light or “cool” blue).

    Incandescent bulbs are also available in a range of color temperatures. The three primary options for consumers include Soft White (roughly 2700K – 3000K), Cool White (3500K – 4100K), and Daylight (5000K – 6500K).

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    CRI (read more here)

    CRI for LED is highly dependent on the particular light in question. That said, a very broad spectrum of CRI values is available ranging generally from 65-95.

    Incandescent bulbs generally have outstanding CRI ratings. A “warm” incandescent light (one with a color temperature of around 2700K) has a perfect CRI of 100. Values trend down a little as color temperature goes up but they tend to stay above 95 (still outstanding).

    Incandescent

    Cycling (Turning On/Off)

    LEDs are an ideal light for purposely turning on and off because they respond rather instantaneously (there is no warm up or cool down period). They produce steady light without flicker.

    Incandescent lights (similar to LED) do not generally flicker and/or cycle on and off as the bulb reaches the end of its useful life. Rather, incandescent light (again, like LEDs) tends to emit less light prior to total failure at the end of its useful life.


    Incandescent lights also turn on rather instantaneously and produce steady light generally without flicker.

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    Dimming

    LEDs are very easy to dim and options are available to use anywhere from 100% of the light to 0.5%. LED dimming functions by either lowering the forward current or modulating the pulse duration. LED lights are not compatible with traditional incandescent dimmers (which lower the voltage sent to the light) so you need to purchase LED dimmer switches as well if you want to dim.

    Incandescent lights are also very easy to dim. Incandescent light is extremely sensitive to voltage inputs and dimming works by exponentially emitting less light as the voltage is reduced. For better or worse (and different than LEDs) incandescent dimming has a larger effect on other characteristics of the light such as power consumption, lifetime, and color temperature.

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    Directionality

    LEDs emit light for 180 degrees. This is typically an advantage because light is usually desired over a target area (rather than all 360 degrees around the bulb). You can read more about the impact of directional lighting by learning about  a measurement called “useful lumens” or “system efficiency.”

    All Incandescent lights emit light omnidirectionally. This means they emit light 360 degrees, requiring fixture housings or reflectors to direct a large portion of the emissions to the desired target area or otherwise wasting the energy required to produce the light.

    LED

    Efficiency

    LEDs are very efficient relative to every lighting type on the market and extremely efficient relative to incandescent bulbs. Typical source efficiency ranges 37 and 120 lumens/watt. Where LEDs really shine, however, is in their system efficiency (the amount of light that actually reaches the target area after all losses are accounted for). Most values for LED system efficiency fall above 50 lumens/watt.

    Incandescent lights are the worst of all the modern lights in terms of efficiency because so much of the energy (90%) goes towards generating heat instead of light. Their source efficiency (the amount of light emitted from the bulb  in general) is around 10 lumens/watt and their system efficiency (the amount of light that actually reaches the target area after all losses are accounted for) is even lower.

    LED



    Efficiency Droop

    LED efficiency drops as current increases. Heat output also increases with additional current which decreases the lifetime of the device. The overall performance drop is relatively low over time with around 80% output being normal near the end of life. Recent advances by researchers who have identified the reasons for droop in LEDs look to reduce losses even further.

    Although incandescent lifespan is extremely short (around 1,200 hours), the bulbs maintain their luminescence really well throughout.

    Incandescent


    Note: recent advances in LEDs will likely improve their droop qualities.

    Emissions (In the Visible Spectrum)

    LEDs produce a very narrow spectrum of visible light without the losses to irrelevant radiation types (IR, UV) or heat associated with conventional lighting, meaning that most of the energy consumed by the light source is converted directly to visible light.

    Incandescent lights emit a very small percentage of their emissions as visible light. A much larger portion is emitted as infrared (essentially heat). Unless you are trying to heat a room with your lightbulbs this is a generally negative feature of incandescent light.

    Incandescent Light Emissions Spectrum

    LED

    - Infrared

    None

    The majority of an incandescent bulb’s emissions are put out in the infrared spectrum (essentially representing losses as heat).

    LED

    - Ultraviolet

    None

    None

    -

    - Heat Emissions

    LEDs emit very little forward heat. The only real potential downside to this is when LEDs are used for outdoor lighting in wintery conditions. Snow falling on traditional lights like HID will melt when it comes into contact with the light. This is usually overcome with LEDs by covering the light with a visor or facing the light downward towards the ground.  

    Incandescent lights emit roughly 90% of their emissions as heat. In some circumstances heat emissions could be beneficial, however, it is a generally a bad thing to emit heat as it represents an energy inefficiency. The ultimate purpose of the device is to emit light, not heat.

    LED

    Failure Characteristics

    LEDs fail by dimming gradually over time. Because LED lights typically operate with multiple light emitters in a single luminaire the loss of one or two diodes does not mean failure of the entire luminaire..

    Incandescent lights generally hard fail meaning they stop working completely and all at once. Incandescent lights burn well throughout their lifetime but the extremely limited time of life (approximately 1,200 hours versus 100,000+ with LEDs) makes them a real bear with maintenance and replacement costs.

    LED

    Foot Candles (read more here)

    Foot candle is a measure that describes the amount of light reaching a specified surface area as opposed to the total amount of light coming from a source (luminous flux). LEDs are very efficient relative to every lighting type on the market. Typical source efficiency ranges 37 and 120 lumens/watt. Where LEDs really shine, however, is in their system efficiency (the amount of light that actually reaches the target area after all losses are accounted for). Most values for LED system efficiency fall above 50 lumens/watt.

    Foot candle is a measure that describes the amount of light reaching a specified surface area as opposed to the total amount of light coming from a source (luminous flux). Incandescent light is generally very inefficient for two principal reasons: first, most of the electricity goes to generating heat. Second, the bulb is omnidirectional meaning a large portion of the emissions are lost to non-relevant areas other than the intended target.

    LED


    Note: Foot Candle ratings are very application specific and vary case by case so relative performance is difficult to generally quantify.

    Lifespan

    LEDs last longer than any light source commercially available on the market. Lifespans are variable but typical values range from 25,000 hours to 200,000 hours or more before a lamp or fixture requires replacement.

    Incandescent lights have the worst lifespan of any bulb on the market (roughly 1,200 hours). Typical lifespan values for an HID bulbs like HPS or CFL are around 10,000-24,000 hours (10-20 times as long). LEDs last 2-10 times as long as HID bulbs which means they last roughly 50-100 times as long as incandescent.

    LED

    Lifetime Costs

    LED lighting has relatively high initial costs and low lifetime costs. The technology pays the investor back over time (the payback period). The major payback comes primarily from reduced maintenance costs over time (dependent on labor costs) and secondarily from energy efficiency improvements (dependent on electricity costs).

    Incandescent lights are by far the cheapest light to purchase on the market but they are a bear to maintain over time because their lifespan is so short. Incandescent lights will likely need to be purchased 20-50 times and the associated labor costs will need to be paid in order to attain the equivalent lifespan of a single LED light. Additionally, incandescent lights have the highest energy costs on the market.

    LED

    - Maintenance Costs

    As a result of the operational lifetimes of LEDs and the frequency with which bulbs have to be changed out, LEDs are by far the best on the market in regards to lifetime costs.

    Incandescent lights will likely need to be purchased 20-50 times and the associated labor costs will need to be paid in order to attain the equivalent lifespan of a single LED light.

    LED

    - Upfront Costs

    LED light costs are high but variable depending on the specifications. The typical 100W-equivalent LED light costs somewhere between $10 and $20.

    Incandescent lights costs vary depending on the specific type of light. They are cheap compared to LEDs ($1-$7 for a 100W bulb).

    Incandescent

    Shock Resistance

    LEDs are solid state lights (SSLs) that are difficult to damage with physical shocks.

    Incandescent bulbs are fragile relative to LEDs as they operate by using a filament encased by a glass bulb.

    LED

    Size

    LEDs can be extremely small (less than 2mm in some cases) and they can be scaled to a much larger size. All in all this makes the applications in which LEDs can be used extremely diverse.

    Incandescent Lamps come in all shapes and sizes but are typically used for indoor and residential applications where size isn’t a major factor. They can be small but not as small as an LED and they do not compare to the small size and robust build of a solid state light like LED.

    LED

    Temperature Tolerance




    - Cold Tolerance

    Minus 40 Degrees Celsius (and they will turn on instantaneously).

    Small delays at very low temperatures can exist as the bulb takes a little longer to warm up to a temperature where light is emitted.

    LED

    - Heat Tolerance

    100 Degrees Celsius. LEDs are fine for all normal operating temperatures both indoors and outdoors. They do, however, show degraded performance at significantly high temperatures and they require significant heat sinking, especially when in proximity to other sensitive components.

    We couldn’t find any objective data on incandescent bulb performance in high temperature situations. If you have any information please contact us.

    -

    Warm-Up Time

    LEDs have virtually no warm-up time. They reach maximum brightness near instantaneously.

    Incandescent lights don’t generally require a warm-up time but there can be a short delay as the filament heats up when operating at extremely cold temperatures.

    LED

    Warranty

    Often 5 to 10 years.

    Typically N/A due to the short lifespan and low purchase price of incandescent lighting.

    LED