Type of Lighting Bulbs (Shapes and Sizes) Part-5


(5) BT (Blown or Bulbous Tube) Type HID Bulbs (Code: ET)

  • BT means “Blown or Bulbous Tube”.
  • (BT )The blown tube light bulb is a HID Tube Type (T) light bulb that has had the glass blown in the middle so that it appears to have a bubble in the middle of the tube.
  • BT halogen light bulbs can be used to replace incandescent light bulbs.
  • Nomenclature: BT28, BT37.
  • Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
  • BTR20 bulb: 20/8 = 2-1/2″ diameter
  • Lighting direction: illuminates its light in one direction.
  • Bulb Technology: High Intension Discharge Lamps, Metal Halide Lamp, Sodium Discharge, Mercury Vapor Lamp and LED.

  • Applications:
  • These are used in sports arenas, car dealerships, canopy lighting, and industrial applications.

Lighting Bulb according to Applications:

(1) Flood Light (Code: F)

  • A flood light is a large, powerful fixture which has a wide beam spread.
  • It is a high-intensity to illuminate a large area. Most often used outside.
  • Floodlights are mostly used to illuminate outdoor playing fields and sports events. It can also be used indoors for lighting stages to create an artificial daytime setting.
  • When choosing a floodlight, some points to be considering like Fixture types, Bulb Type, Type of mounting wall-mounted, ground-mounted and post top.
  • Nomenclature: F40, F20.
  • Numbers in each code refer to the bulb’s diameter in one-eighths of an inch.
  • Bulb Technology: Fluorescent , Metal halide lamps, LED, Halogen

  • Application:
  • Advertisement board and Subway
  • Airport and Architecture lighting
  • Football and tennis field
  • Tunnels and parks
  • Clubs, Bars, Hotels and Art galleries
  • Villa and parking lot

(2) Panel Lighting:

  • LED panel lights are very thin either surface or recessed mounted ceiling light.
  • Panel lights are square, Round or rectangular.
  • LED panel lights are high-grade indoor lighting lamps.
  • They are made of aluminum alloy by anodic oxidation.
  • It has simple design and appearance with adorable illumination effects.
  • It comes with different powers like 12W, 18W, 21W, 36W, 48W, 72W, and 85W.
  • It used for home application and easy to install by recessed application with clamping springs.
  • Recess mounted Slim Circular type LED color changing panel light in white finish with anti-glare diffuser and separate energy efficient electronic driver.
  • Nomenclature: Panel
  • Lighting direction: illuminates its light in one direction.
  • Bulb Technology: LED, CFL.

  • Applications:
  • Low-profile 6″ Round LED Panel Light for kitchen lighting, living room lighting, office lighting, basement lighting, museum lighting, hospital lighting.

(3) Down Light

  • Downlights in help to create a feeling of more space, clean lines, and a clutter-free environment.
  • A downlight is mostly hidden in or above the ceiling. The only visible part of the light fitting is the decorative rim, and the light bulb in the middle. Everything else is held in place in the ceiling by spring clips that stop the whole thing giving in to gravity and falling out.
  • Nomenclature: Down Light.
  • Lighting direction: illuminates its light in one direction.
  • Bulb Technology: LED, CFL.

  • Applications:
  • Downlight especially in kitchens and bathrooms have become very popular, as they provide a modern appearance to the room. More recently the trend has spread to every other room. Lounges, bedrooms and hallways all look great when fitted with recessed downlight.

Difference Between Panel Light and Down Light.

  • There is confusion between Panel light and Down Lights. Both Lights are either Round or Square shaped, so we cannot easily difference between them.
  • There are some differences between LED panel light and downlight in following points.
  • Structure
  • Both have a diffuser to spread out light. The panel light has a light guide plate (LGP) which guides light across the panel so that it is evenly spread. There is a reflector plate right at the back of the LED guide plate (LGP) which reflect lighting source.
  • The downlight does not have this type of arrangement.
  • Lighting
  • Inside LED panel light, the LED is fitted around (In a circular frame). The LGP and the diffuser gather the light and spread it creating an evenly soft lighting.
  • The downlight lighting on the other hand have a LED in the middle. Consequently, the light produced is brighter than in the round panel light.
  • Size of Heat Sink:
  • Typically, the downlight has a thicker heat sink than the panel light.
  • Fixture Thickness:
  • LED panel light is super thin, looks simple but stylish.
  • Fixture Size Vs Lumen:
  • To spread light uniformly all Panel light are made with high dimension fixture. As you increase output watt you will have to choose bigger and bigger.
  • Power Saving:
  • Panel lights are less power saver compared to Down Light.
  • Panel lights have efficiency of only 60-80 Lm/watt compared to down light which has efficiency of 100-120 Lm/watt.
  • Applications:
  • If you are looking for bright LED lighting, your best choice will be the downlight. However, if you are angling for a softer and relatively polished feel to the room, then go for the round panel.

(4) Strip Light

  • Strip lights are available in both tape and rope configurations.
  • Nomenclature: Strip
  • Lighting direction: illuminates its light in one direction.
  • Bulb Technology: LED

  • Applications:
  • Under-counter Lights, cove Lights, Display lighting and Exterior Lighting


Bulb Shapes and Applications

CodeBulb Shape DesignationsType of BulbsApplications
AArbitraryIncandescent ,CFL ,LED, Metal Halide, High Pressure Sodium ,Mercury vapor,In household light.

Table lamps.

Wall Light, Ceiling lights.

ARArbitrary with ReflectorIncandescent ,CFL ,LED, Metal Halide, High Pressure Sodium ,Mercury vapor,In household light.

Table lamps.

Wall Light, Ceiling lights.

BBulgedIncandescent ,CFL ,HID,LEDIn various light fixtures,

Decorative Lights.

BTBlown TubularIncandescent ,CFL ,HID,LEDLess in general used,

In various light fixtures.

Table Lamp.

BRBulged ReflectorIncandescent ,CFL ,HID,LEDIn Track lighting (spot lights)

In recessed lighting.

MRMirror ReflectorLEDIn Track lighting
CCandleIncandescent ,CFL ,HID,LEDWidely used in ceiling and table chandeliers and decorative light fixtures.

In small appliances and indicator lamps

They have a smaller base.

CACandle AngularIncandescent ,CFL ,HID,LEDLike Candle bulbs, used in chandeliers and similar light fixtures.

They also often have a smaller base.

CWCandle TwistedIncandescent ,CFL ,HID,LEDThese are used in chandeliers and have smaller bases.
CPCrystalline PearIncandescent ,CFL ,HID,LEDUsed in various decorative light fixtures

in wall lights, ceiling lights and table lamps.

To create interesting reflective effects.

EEllipsoidalIncandescent ,CFL ,HID,LEDWidely used in various light fixtures.
ERExtended ReflectorIncandescent ,CFL ,HID,LEDin track lighting and other fixtures for spot lights.
FFlambeauIncandescent ,CFL ,HID,LEDin chandeliers and similar decorative interior lighting fixtures.
GGlobeIncandescent ,CFL ,HID,LEDWidely used in ceiling and table lamps.

in Bathrooms.

In ornamental lighting and some floodlights

GADecoratorIncandescent ,CFL ,LEDUsed in ceiling lamps, table lamps and other decorative fixtures.
HXHexagonal CandleIncandescent ,CFL ,LEDUsed in chandeliers and other decorative light fixtures to create beautiful reflective light effects.
PPearIncandescent ,CFL ,LEDUsed in various light fixtures.

In standard for streetcar and locomotive headlights

PARParabolic Aluminum ReflectorIncandescent ,CFL ,LEDWidely used in track lighting and spot light fixtures.

used in floodlights

PCOgiveIncandescent ,CFL ,LEDUsed in decorative light fixtures.
PSPear StraightIncandescent ,CFL ,LEDUsed in various light fixtures.
RReflectorIncandescent ,CFL ,LEDWidely used in Recessed cans  and track lighting ,spot light fixtures.
SStraight SidedIncandescent ,CFL ,LEDUsed in various light fixtures.

lower wattage lamp as sign and decorative

STStraight TubularIncandescent ,CFL ,LEDUsed in various light fixtures.
TTubularIncandescent ,CFL ,LEDUsed in various light fixtures according to functional rather than decorative purposes.

Showcase and appliance lighting =In closets/garages.

TATubular AngularIncandescent ,CFL ,LEDUsed in various light fixtures, often for decorative effect.