Light Bulbs 101 - Answering all your common light bulb questions

1. What are the different light bulb fittings you get?

The light bulb cap provides an electrical connection to the lamp and ensures the light bulb is correctly fitted in the light fitting or base. It is essential to know the base type to identify the light bulb cap. Below we have listed the most popular light bulb caps available in South Africa. 

Name	Code	Image	Use
Bayonet (BC)	B22		Used in a wide range of applications. Mainly for domestic use.
Edison Screw (ES)	E27		Developed by Thomas Edison in the 1800s. Used in a wide range of applications. Mainly for domestic use. Most popular edison fitting.
Small Edison Screw (SES)	E14		Used in a wide range of applications. Mainly for domestic use. Less popular than the E27.
Giant Edison Screw (GES)	E40		Used in a wide range of applications. Mainly for industrial use in larger wattages.
220V Spotlight Bulb	GU10		Used mainly in spotlights. Uses a twist and lock mechanism. Works with 220V alternating current.
12V Spotlight Bulb	GU5.3/MR16		Used for spotlights and is less popular than the GU10. Uses a direct connection and works with a 12V-220V transformer.
Capsule Bi Pin	G4		Used on many small incandescent light bulbs, especially halogen lamps. Primarily used in 12V applications with transformers.
Capsule Curled Pins	G9		Used for 220V capsule light bulbs, where no transformer is built into the fitting.
Linear Halogen	R7S		These are longer light bulbs with their connections at both ends. These bulbs are most likely to be used in flood lights and display cabinets.
Standard Linear Fluorescent and LED Tube	T8		The most common size fitting for fluorescent and LED tube fittings. Uses 2 pins on each side of the bulb to fit and power up the bulb.
Slim Linear Fluorescent and LED Tube	T8		A less common size fitting for fluorescent and LED tube fittings. Uses smaller pins to fit on a thinner tube for slimmer light fittings.

2. What are the different light types available?

Incandescent

In Incandescent lamps, a heating material is used to generate light until it reaches a temperature at which it glows. When electricity is passed through the material, the material becomes hot and bright which presents itself as the light from the bulb. 

High Intensity Discharge (HID)

HID bulbs are generally used in industrial and outdoor applications where there is a need for a bright light source. HID represents a large family including High Pressure Sodium (HPS), Metal Halide (MH) and Mercury Vapour (MV). HID bulbs generate light by creating an arc of electricity in the environment of the metal within the bulb. 

Halogen

Halogen bulbs deliver direct light and are used for displaying different shapes of light for visual interest. Halogen bulbs contain halogen gas which surrounds the filament in the bulb which is used to generate the lighting effect. 

Fluorescent Lamps and CFL

Fluorescent lamps are essentially hollow glass tubes filled with vaporized metal. These lamps also contain a small amount of mercury and are available in a wide range of size, shapes and colours. 

LED

LED bulbs are the most popular form of light today and are rapidly replacing the previously mentioned sources of light. LED bulbs generate light by illuminating a diode by passing electricity through it constantly.

 

3. What are the different light bulb shapes that are available? 

Name	Description	Image
Standard Classic	This is the classic light-bulb shape most people think of when they imagine a light bulb and are commonly available with both Bayonet and Edison Screw Cap fittings. They are most often used in the home in ceiling lights, table and floor lamps, reading lamps, etc.
Golf Ball	Golf ball bulbs are named according to their shape and can also be referred to as a mini bulb. Their compact sizes make them well suited to fixtures and lamps with limited space. Because of their appealing design, they are great for decorative purposes.
Candle Bulbs	Candle bulbs are named according to their shape and are slim designed. Their compact sizes make them well suited to fixtures and lamps with limited space.
Compact Fluorescent Lamp / Twisted Fluorescent Lamp	Compact Fluorescent Lamps are the common energy-saving bulbs people use in their houses. Twisted Fluorescent Lamps are similar, however, the light is in a twisted, rounded shape. Although they are ideal for domestic use, they are also used in other areas, such as corridors, warehouses, sports centers and more.
Spotlight Bulbs	Spotlight bulbs have a lining of a reflective surface that helps to create a wide beam angle. Spotlight bulbs are available as incandescent, halogen and LEDs and usually connect through 2 pins that fit into the socket through a push and twist action. Spotlights are commonly found in security and kitchen lights and dimmable options are available.
Fluorescent and LED Tubes	Led or fluorescent tubes are also referred to as the strip or tube lights. They are long round tubes, commonly found in domestic and commercial applications. They are a relatively cheap form of lighting and offer a long lifespan.
Circular Fluorescent Lamps	Circular fluorescent light bulbs are the same as the fluorescent tube lights, only in a smaller, circular shape. They are perfect for compact areas where lighting space is limited.
2D Fluorescent Lamps	2D fluorescents are the same as fluorescent tube lights, but bent in a u-shape and almost mimics the look of a stove element. They are commonly found in hard-to-reach areas that require lots of light, such as utility areas, stairwells, corridors, and bulkheads.
Reflector Spotlights	Similar to spotlights, reflector light bulbs are lined with a reflective surface on the inside to create a wider beam angle. These bulbs are available as halogen and LEDs. They are often used in security and kitchen lighting and dimmable options are available.
High Discharge Tubular	Tubular lamps are tube shaped light bulbs of various lengths that can have different base types and have a variety of applications including outdoor, domestic, retail, factory, and warehouse lighting.
High Discharge Elliptical	Elliptical lamps are egg shaped light bulbs and are mainly used in industrial applications.
Capsule Bulbs	Capsule shaped light bulbs are exactly as the name suggests and are designed for use in small light fittings. They come with various base fitting options. These bulbs are commonly used in kitchens, display cabinets, etc.
Linear Lamps	Linear light bulbs are not similar in design as fluorescent tube lights, although they may sound similar. They are long, see-through tubes that have the halogen or LED parts exposed. They also come with the double ended Base / R7 caps at the ends.
Pygmy Lamps	Pygmy light bulbs are small in size, perfect for display cabinets, fridges, sewing machines, etc. They also come with various base fitting options.

 

4. What is lightbulb wattage?

Watt (W) is the unit of measurement of energy transfer and that can also be defined as 1 Joule per second.

The higher the wattage on a light bulb, the more electricity is needed to run the light bulb, meaning a higher cost to run.

 

5. What are lumens?

Lumen (lm) is the unit of measurement of the total amount of visible light emitted from a source, such as a light bulb. This is a standard unit of measurement and can be found on most light bulb packaging as a guide. 

 

6. What’s the difference between watts and lumens?

Lumens are used to describe how much light a light bulb will emit, whereas wattage will indicate the amount of energy the light bulb uses.

 

7. What’s the difference between lumens and lux?

One lux is equal to one lumen per square meter and can also be described as the light intensity in a specific area. Lux enables you to measure the total amount of light output in a specific area.

 

8. How do I determine light bulb brightness?

To determine the brightness of a lightbulb, you can have a look at the Lumens, however, factors like current, voltage, the type of bulb, the light output ratio of the light fixture and whether the lights are in parallel or in series, can also affect the overall brightness of the light bulb.

But when buying light bulbs, lumens are a good indicator to look at to determine the brightness of the light or lamp.

 

9. What is the light bulb colour temperature?

Light bulb colour temperature is the scale that measures how ‘warm’ (yellow) or ‘cool’ (blue) the light from the light bulb is and it is measured in degrees of the Kelvin scale (K). 

A higher ‘K’ number indicates ‘cooler’ light and a lower ‘K’ number indicates ‘warmer’ light.

 

10. How do I know which light bulb colour temperature to choose?

There are different factors that you will have to consider when choosing which colour temperature is most suitable for the space you want to replace the lighting in. You’ll need to consider things like the type of room you want to place the light bulb in, the atmosphere you want to create and what the lighting will mainly be used for.

Below is a guideline of the different colour temperatures:

Warm White (3000K)

Warm white light has an inviting feel to it. The warm white light temperature is best suited for places where coziness plays an important role, such as bedrooms, restaurants, theaters, hotels, etc, as it will give a warm appearance in the room.

Cool White (4000K)

The cool white light colour temperature has a more neutral appearance, without it coming across as too cold. This colour temperature is commonly used in classrooms, offices, warehouses, showrooms, and living rooms. Cool white light is best for reading and performing relaxing tasks without straining the eyes. 

Daylight (6000K)

The daylight colour temperature is a bright white light with a hint of blue which gives a room a modern white appearance. It is especially suitable for specific situations and areas, such as operating rooms, workshops, and modern homes where it's crucial to have enough ‘natural daylight’ in the room.

 

11. Why are there different light bulb sizes?

Various light fittings exist for various different purposes, such as stove lighting, fridge lighting, ceiling lighting, table lamp lighting, etc. so different light bulbs were created to meet the needs of the various fittings.
Other reasons may include aesthetic purposes and various brands creating competition by introducing different products to the market.

 

12. Are all light bulbs dimmable?

The short answer is no. Not all light bulbs are dimmable. 

By nature, incandescent light bulbs are dimmer-friendly because of the way they work. 

Halogen Light Bulbs function in more or less the same way as incandescent light bulbs, which makes them dimmable as well. 

Compact Fluorescent Lights on the other hand are not good to use with dimmers, as adjusting the dimmer switch to a lower voltage will shut it off completely. However, CFLs can be compatible with dimmer switches if they have the right dimmable ballast. 

Some LED light bulbs are dimmable, while others are not. Dimmable LEDs however, do provide smooth dimming when the correct LED is matched with the correct dimming system.

13. What is a light bulb adapter?

A light bulb adapter allows you to use a light bulb with a different base than what matches the original light fitting. As an example, if you have a bayonet cap light bulb, but an Edison screw light fitting, you can use an adapter that screws into the fitting, but the light bulb with twist into the adapter, allowing you to still use the light bulb, even though it doesn’t match the original fitting.

 

14. What do I need to install dimmable light bulbs?

To install dimmable light bulbs, you would need a dimmer module on the light switch, a dimmer regulator behind the light switch and dimmable globe(s).

Refer to point 12 to find out more about dimmable light bulbs.

 

15. Do LED light bulbs get hot?

Although LED light bulbs run a lot cooler than incandescent bulbs, they still produce heat and get hot, however, the heat is pulled away by a heat sink in the base of the bulb. So, they do not get nearly as hot as incandescent bulbs would.

 

16. Are LED lights safe?

LEDs from reputable manufacturers do not contain toxic substances that can harm you and LEDs can be recycled easily. Compared to older light bulb types that contained substances like mercury, LED lights are generally safer, however, everything we use in our modern age has its pros and cons.

 

17. Are LED lights cheaper to run?

LED light bulbs have a massive energy efficiency benefit. When comparing them to incandescent bulbs, LEDs are 80% more efficient and turn 95% of their energy into light, whereas incandescent bulbs would produce a lot of heat instead of using that energy to produce light.

 

18. How long do LED light bulbs typically last?

LEDs are the longest-lasting light bulbs, and can have a lifespan of up to 50,000 hours.

However, external factors such as voltage fluctuations and unpredictable power conditions might affect the lifespan of these bulbs.

 

19. How are LED light bulbs different from other types of light bulbs?

- LEDs use less energy than other light bulb types
- LEDs have a much longer lifespan than other light bulb types
- CFLs typically dim at first and take a while to warm up to full brightness, whereas LEDs produce light to their full capacity immediately when switched on.
- Other light bulbs will typically work with wire filaments to produce light, whereas LEDs use a light-emitting diode and don’t have wire filaments.
- Regular light bulbs produce much more heat than LED light bulbs.

 

20. What are emergency bulbs?

An emergency LED light bulb is basically an inverter light bulb. 

The advanced technology used in emergency LED light bulbs enable them to automatically turn on the LED light during a power cut and automatically charge the internal lithium-ion batteries when AC mains is available.

This basically means that these emergency bulbs are 2-in-1 type bulbs, as it works as a normal light bulb when it has AC mains power, but it will also work as an emergency light bulb when there is a power cut.

Because it uses lithium-ion batteries, the batteries inside the light bulb need 3 to 4 hours of charging time to fully charge and thereafter, it will automatically cut off the charging to prevent the batteries from overcharging. 

Because it has an internal backup power source and electronic control circuit, the bulb can detect the state of the switch (on/off) even when there is a power cut. 

 

21. What is a light bulb beam angle?

The beam angle of a light bulb describes the angle at which the light is emitted. The beam angle of the light bulb will depend on the light bulb type, shape, size, wattage & colour.

 

22. How should I safely dispose of my light bulbs?

How to safely dispose of your light bulbs would depend on the type of light bulb you have. Some light bulbs you can dispose of in your regular garbage, whereas others you cannot. It also depends on the country you live in and what the various directions on the packaging indicate, so be sure to always check out the packaging for safety and disposal directions.

Incandescent Light Bulbs

Incandescent Light Bulbs can be disposed of in normal household waste, as they cannot be recycled. 

Compact Fluorescent Lamps (CFL)

Compact fluorescent lamps don’t really belong in your regular garbage and should be disposed of where it can be collected for recycling.

Halogen Lamps

Halogen light bulbs can be disposed of in normal household waste, as they cannot be recycled.

LED Lamps

LEDs do not contain harmful substances and can be disposed of in household waste. 

Fluorescent Tube

Fluorescent lamps don’t really belong in your regular garbage and should be disposed of where it can be collected for recycling.

 

23. How do I handle light bulbs with mercury?

Since no mercury is released when CFLs are intact or in use, but they do still contain mercury, so they should be handled with care to prevent them from breaking.

Find out more: https://britelighting.co.za/blogs/news/top-10-lighting-trends-for-2021