What should you know before buying LED Bulbs (Part:2)

(3) Correlated Color temperature (CCT):

  • Color temperature refers to the light’s color characteristics.
  • Color Temperature is measured in Kelvin.
  • It refer to the warmness or coolness of the light that bulb produces.
  • The color temperature of a light source is a numerical measurement of its color appearance.
  • This temperature is based on the principle that any object will emit light if it is heated to a high enough temperature and that the color of that light will shift in a predictable manner as the temperature is increased.
  • Color temperature is a description of the warmth or coolness of a light source. When a piece of metal is heated (temperature increases) the color of light it emits will change. This color begins as red in appearance and graduates to orange, yellow, white, and then blue-white to deeper colors of blue.
  • Color Temperature is not an indicator of lamp heat.
  • The sun, for example, rises in morning at approximately 1800 Kelvin and changes from red to orange to yellow and to white as it rises to over 5000 Kelvin at high noon. It then goes back down the scale as it sets in evening.
  • The warm white ranges from about 2700k to 3800k, natural white ranges from 3800k to 4800k, pure white or daylight from about 4800k to 6000k. Cool white starts from around 6000k upwards.
  • Colors and light sources from the red/orange/yellow side of the spectrum are described as warm (incandescent) and those toward the blue end are referred to as cool (natural daylight).
  • In Color Temperature Value higher Kelvin temperatures (3600–5500 K) are consider cool and lower color temperatures (2700–3000 K) are considered warm.
  • When choosing a color, the two considerations are important one is color rendering (How well the light shows the true color of objects) and temperature.

(1) Soft White / Warm White (2700K- 3000K):

  • Warm light is preferred for living spaces because it is more flattering to skin tones and clothing.
  • Recommended for indoor general and task lighting applications.
  • Living rooms
  • Bed rooms
  • Rooms decorated in earthy tones (reds, oranges, and yellows)
  • It gives effect like incident or halogen Light.

(2) Natural / Cool White (3500K- 4500K):

  • Cool light is preferred for visual tasks because it produces higher contrast than warm light.
  • Recommended for use in Domestic Applications.
  • Warmer Whites are preferable in living and dining areas as well as reception areas to create a more relaxed environment.
  • Natural Whites are preferable for kitchens and bathrooms where tasks are performed.
  • Suitable for work areas where contrast is important.
  • Kitchen
  • Bath rooms
  • Rooms decorated in airy, fresh hues (blues, greens, whites)
  • It gives effect like Fluorescent Light.

(3) Bright White (4500-5000K):

  • Recommended for use in:
  • Office
  • Study Room

(4) Daylight / Full Spectrum (5000K- 6500K):

  • Recommended for use in:
  • Garage
  • Office
  • Industrial and hospital areas.

  1

                                                         Lighting Source CCT
Source Color temperature in Kelvin
Skylight (blue sky) 12,000 – 20,000
Average summer shade 8000
Light summer shade 7100
Typical summer light (sun + sky) 6500
Daylight fluorescent 6300
Xenon short-arc 6400
Overcast sky 6000
Clear mercury lamp 5900
Sunlight (noon, summer, mid-latitudes) 5400
Design white fluorescent 5200
Special fluorescents used for color evaluation 5000
Daylight photoflood 4800 – 5000
Sunlight (early morning and late afternoon) 4300
Brite White Deluxe Mercury lamp 4000
Sunlight (1 hour after dawn) 3500
Cool white fluorescent 3400
Photoflood 3400
Professional tungsten photographic lights 3200
100-watt tungsten halogen 3000
Deluxe Warm White fluorescent 2950
100-watt incandescent 2870
40-watt incandescent 2500
High-pressure sodium light 2100
Sunlight (sunrise or sunset) 2000
Candle flame 1850 – 1900
Match flame 1700
Skylight (blue sky) 12,000 – 20,000
Average summer shade 8000
Light summer shade 7100
Typical summer light (sun + sky) 6500
Daylight fluorescent 6300
Xenon short-arc 6400
Overcast sky 6000
Clear mercury lamp 5900
Sunlight (noon, summer, mid-latitudes) 5400
Design white fluorescent 5200
Special fluorescents used for color evaluation 5000
Daylight photoflood 4800 – 5000
Sunlight (early morning and late afternoon) 4300
Bright White Deluxe Mercury lamp 4000
Sunlight (1 hour after dawn) 3500
Cool white fluorescent 3400
Photoflood 3400
Professional tungsten photographic lights 3200
100-watt tungsten halogen 3000
Deluxe Warm White fluorescent 2950
100-watt incandescent 2870
40-watt incandescent 2500
High-pressure sodium light 2100
Sunlight (sunrise or sunset) 2000
Candle flame 1850 – 1900
Match flame 1700

 2

                                CCT – Correlated  Color  Temperature

Kelvin Associated Effects Type of Bulbs Appropriate Applications
2700° Warm White, Very Warm White incandescent bulbs Homes, Libraries, Restaurants
3000° Warm White most halogen lamps, Slightly ‘whiter’ than ordinary incandescent lamps Homes, Hotel rooms and Lobbies, Restaurants, retail Stores
3500° White Fluorescent or CFL Executive offices, public reception areas, supermarkets
4100° Cool White   Office, classrooms, mass merchandisers, showrooms
5000° Daylight Fluorescent or CFL Graphic industry, hospitals
6500° Cool Daylight Extremely ‘white’ Jewelry stores, beauty salons, galleries, museums, printing

 

 

 

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About Jignesh.Parmar
Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical) from Gujarat University. He has more than 14 years experience in Power Transmission-Power Distribution-Electrical energy theft detection-Electrical Maintenance-Electrical Projects(Planning-Designing-coordination-Execution). He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. He is Freelancer Programmer of Advance Excel and design useful Excel Sheets of Electrical Engineering as per IS,NEC,IEC,IEEE codes. He is technical Author for "Electrical Mirror" and "Electrical India" Magazines. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. He wants to Share his experience & knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics.

6 Responses to What should you know before buying LED Bulbs (Part:2)

  1. Ms. Su Mon Myint says:

    Thanks a lot for sharing!
    I am interested in lighting and illumination article.
    This is very useful for me.

  2. birbal Kumar says:

    Very thankful for this valueable notes.Mentioned very clearly with colour temp. of all lights, thanks again…

  3. zamir Ahmad says:

    Dear Jignesh,Regard. You are providing good information & notes in Electrical note,keep it up regullarly

  4. Vikram Ram says:

    Thanks Sir,

    Please send me the deatil about choose the cable size as per load requirement.

    Regards.

    Bikram Singh

    On Wed, Aug 3, 2016 at 8:27 PM, Electrical Notes & Articles wrote:

    > Jignesh.Parmar posted: “(3) Correlated Color temperature (CCT): Color > temperature refers to the light’s color characteristics. Color Temperature > is measured in Kelvin. It refer to the warmness or coolness of the light > that bulb produces. The color temperature of a light sou” >

  5. man mohan prajapati says:

    thanks sir
    sir apsey help chaye mujhe basik sikhana he miner funde example load ke hisab sey cable ,mccb ,change over connection,d.o. T/F, kya market me apke naam sey koi book hindi midum me mil jayegi plese help sir

  6. very nice Mr.
    Jignesh

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