This is a very easy to follow guide about the light bulbs we use in our homes and businesses. It covers the most popular energy saving light bulbs and fluorescent tubes. This includes LED light bulbs because LED bulbs are the best energy saving bulbs.
I have broken the guide down into four sections to make it easier to read. The information in these groups will give you a greater understanding of the bulbs available.
Over time, there will be changes to each of these sections to keep all the information up to date. To get the full benefit, you can read the whole guide or scroll to the part that interests you the most. When you have finished reading, you will know everything there is to know about these amazing lamps and what they can do for you.
The Light Bulb Guide: What you need to know about –
- LED Bulbs – Light Emitting Diode
- Low Voltage Lamps
- CFL Bulbs – Compact Fluorescent Lamps
- Fluorescent Tubes
LED Bulbs – Light Emitting Diode
There is no doubt that LED bulbs are the most cost effective way of lighting. Because of this, lighting technology has been geared towards LED more than ever. Over the last few years, it has led to many improvements and it has become very popular.
There were difficulties in achieving high levels of light and wide beam angles. Fortunately, these difficulties have been resolved. Without compromise, you can now replace almost any incandescent lamp with these new bulbs.
Here you will find an easy to follow introduction to LED bulbs. It should give you a better understanding of what they can do for you.
LED stands for Light Emitting Diode and they are nothing like the standard light bulbs in everyday use. They do not have delicate parts that can easily break or blow. They use very little energy when compared with other forms of lighting and radiate virtually no heat.
They are also believed to be safer because they do not contain any toxic components. On top of that, they can have a very long life span, sometimes lasting over 25,000 hours.
To begin with the range of LED bulbs was very limited. Just a few, like the low voltage dichroic and GU10 lamps were introduced. Many of these bulbs were available in only one watt making them of very little use. It was believed that background or decorative lighting would be their main role.
A Full Range Of Energy Saving LED Light Bulbs
Gradually more and more LEDs were made available. This includes LEDs in GLS, globes, candles, reflectors and most of the Par range of lamps.
The wattage slowly increased and in many cases, made them as bright as the halogen variety. What’s more they were made with all the usual caps to fit most lampholders. Now there are energy saving LED light bulbs to replace just about every incandescent, low voltage and fluorescent tube.
Low Voltage Lighting Transformer Or LED Drivers
The new LEDs are made to the same dimensions as the old variety of lamps they were designed to replace. Whether it’s down lights, track lights or wall lights, in most cases the LED will fit without any difficulty. Installing them in mains voltage light fittings should not be a problem.
For low voltage lights, the low voltage lighting transformer should be able to run the LEDs. However, it’s worth noting they may reduce the life of the bulb. If they cannot, the transformers will have to be replaced with LED drivers.
With some low voltage lighting, this is not always possible. Track lighting, for instance, has the transformer attached to the end of the track. In situations like this, the light fitting will usually have to be replaced.
LEDs – The Ideal Outdoor Bulbs
LEDs are ideal for use outdoors as they are unaffected by the cold. They have no fragile filaments or components that can get knocked and broken.
They are completely shock resistant and unaffected by bad weather. These are some of the reasons why they are perfect for use in garden and other outside lighting.
Using A Trailing Edge Dimmer Switch For LED Bulbs
Most LEDs are available in dimmable and non-dimmable versions. If you intend to use the dimmable variety, you may have to use special LED dimmers. The trailing edge dimmer switch for LED bulbs is designed to work with lower wattages.
However, if you are using a standard dimmer at the moment, it may work OK. One option is to install the LEDs and see what happens.
Using standard dimmer switches could mean reduced light output but this may be minimal. If you are happy with their performance then all well and good. If there are problems with dimming, flickering or the dimmer starts buzzing, it will have to be changed.
MR11 LED, MR16 LED And GU10 LED In Three Colours
Most LEDs are available in three colours and they are warm white, cool white and daylight. The popular MR11 LED, MR16 LED and GU10 LED are all available in these three colours.
The warm white (2700K to 3000K) is usually reserved for domestic lighting because it best matches the colour of standard household bulbs. Cool white (4000K) is a very bright white often used in hospital and office lighting. The colour daylight (5000K to 6500K) is a good choice for rooms without windows as it imitates natural light very well.
How Long Do LED Light Bulbs Last
When LEDs were first introduced, one of the main benefits advertised was the long life of the lamp. Nearly all the manufacturers were claiming a life span of 50,000 hours. Very quickly people began to doubt that prediction.
To assess value for money consumers wanted to know – how long do LED light bulbs last. Today, most agree 50,000 hours was an exaggerated claim and 25,000 hours would be more realistic. Using LEDs for 5 hours a day means they should last for about 13 years.
The Dimmable LED Bulbs Will Save You Even More Money
LEDs do not have to warm up, they reach full brightness as soon as they are switched on. Although LEDs have greatly reduced wattages, they are able to match the brightness of other bulbs. This is because they are much better at turning power into light.
LEDs are able to convert 80% of their power to light. Incandescent lamps can only convert about 20%. LEDs, therefore, have the potential to save you a great deal of money.
They can reduce your lighting costs by as much as 90%, regardless of whether its domestic, commercial or industrial lighting. With lighting representing 20% of your electricity consumption, it is easy to see there are savings to be made. By using dimmable LED bulbs you can save even more.
However, it’s not just about saving money by burning fewer watts. Because of their life span, lamp replacement is virtually eliminated. Complete re-lamping within business premises will more or less become a thing of the past.
The LED Bulb Is Safer Than Any Other Lamp
The LED bulb is much safer than other lamps. They are free of the toxic heavy metals usually associated with lamps. They contain no lead, mercury or other dangerous ingredients.
They will not get hot and burn you when they come into contact with your hands. When replacing it makes them much easier to handle.
There is also very little glass used in the manufacturing process which makes them difficult to break. Therefore, there will be far less breakages either in transit or on site.
Low Voltage Lamps – The MR16 Bulb And MR11 Bulb
The most popular of the MR lamps is the MR16 bulb and MR11 bulb. The MR stands for Multifaceted Reflector and the number is the diameter in eights of an inch.
The MR16 bulb is 16 eights (51mm) of an inch and the MR11 bulb is 11 eights (35mm) of an inch in diameter. The diameter is measured across the widest area at the front of the lamp. It is also known as the measurement across the face or bowl of the lamp.
The MR lamps are very robust. The wire coil filaments of these lamps are five times thicker than that of a mains voltage bulb. When stretched out, the filament is also much shorter in length. This allows the low voltage lamp to have a very long life.
Here is a list of MR16 51mm diameter dichroic lamps –
M268 20W 12V 10° Narrow Spot Beam
M269 20W 12V 36° Wide Flood Beam
M271 35W 12V 10° Narrow Spot Beam
M281 35W 12V 36° Wide Flood Beam
M249 50W 12V 10° Narrow Spot Beam
M250 50W 12V 24° Medium Flood Beam
M258 50W 12V 36° Wide Flood Beam
M280 50W 12V 55° Very Wide Flood Beam – more about the MR16 lamps here.
These are the smaller MR11 35mm diameter dichroic lamps –
M200 10W 12V 36° Wide Flood Beam
M252 20W 12V 10° Narrow Spot Beam
M221 20W 12V 36° Wide Flood Beam
M265 35W 12V 10° Narrow Spot Beam
M223 35W 12V 36° Wide Flood Beam – more about the MR11 lamps here.
Dichroic Lamps Or Aluminium Reflector Lamps
The MR11 bulb is a dichroic lamp. The MR16 bulb can be either a dichroic lamp or aluminium lamp. The dichroic lamps and the aluminium reflector lamps look identical.
The dichroic lamps allow heat to pass straight through and out the back of the lamp but reflects light forward. One of the benefits of this is that they produce a light beam with a cool temperature. That makes them perfect for use where you have staff working right underneath them.
The cool beam of the dichroic lamps will protect sensitive materials on display in shop windows or around the home. On the other hand, the aluminium reflector lamps will reflect forward both the heat and the light.
MR 12V Light Bulbs – Wattages And Beam Angles
The power rating of the MR16 bulb will usually range from 20 to 50 watts and the MR11 bulb from 10 to 35 watts. The beam angles start at ‘spot’ and go right up to ‘very wide flood’. This gives you the choice of a pencil thin beam of light or a wide illuminating flood beam.
But whatever the beam angle, the light will be refreshingly bright and crisp.
Because they are 12V light bulbs, you will need a transformer to reduce the voltage. The use of dimmable transformers and low voltage dimmers can also have its advantages. It will give you full control over the brightness and effect of the lighting.
The G4 Bulb And GY6.35 Bulb
A range of low voltage halogen bulbs that comes in two sizes. They include the G4 bulb and GY6.35 bulb. They are also known as a G4 capsule and GY6.35 capsule, both of which are available in several wattages.
These bulbs are very small which enables them to fit into places that other lamps cannot. They have allowed lighting manufacturers to produce elegant wall and ceiling lights. At one time, these small artistic light fittings would have been out of the question.
How To Identify Your Halogen Capsule Bulbs
If you are in doubt about which of the two halogen capsule bulbs you require, there are several ways you can find out. The lampholders and capsules should be clearly marked with the wattage and either a G4 or GY6.35 stamp. However, these markings do fade over time and become invisible to the human eye.
If they have disappeared, you can take a measurement of your capsule if you have one. The G4 bulb will measure 4mm between the pins and be about 33mm long. The GY6.35 bulb will be 6.35mm between the pins and about 44mm in length.
If you do not have a lamp, you can measure the space between the pin holes in one of the lampholders. This will quickly establish which one of the two halogen capsule bulbs you need. All you have to do now is work out the wattage.
Popular sizes for the G4 bulb would be 10W and 20W. The GY6.35 bulb could be 20W, 35W, 50W or 100W. If you are unable to see the wattage on the lamp, the maximum wattage should be printed on the light fitting.
Here is a list of G4 and GY6.35 capsule bulbs
M9 5W 12V G4
M91 10W 12V G4
M47 20W 12V G4 – find out about the G4 lamps here.
M76 20W 12V GY6.35
M75 35W 12V GY6.35
M32 50W 12V GY6.35
M73 75W 12V GY6.35
M180 90W 12V GY6.35
M28 100W 12V GY6.35 – find out about the GY6.35 lamps here.
Inserting Halogen Capsule Light Bulbs Into Lampholders
When removing from the packaging the glass lamp should not be touched by bare hands. Natural body oil transfer from the hands to a lamp can reduce its life. When removed from their boxes the halogen capsule light bulbs may be in sealed paper wraps.
By holding the body of the lamp in one hand, the end of the wrap can be cut off. The capsule lamp can then be squeezed out (see picture) and inserted straight into the lampholder. If you have to handle the capsule always pick it up by the pins and hold the glass body in a piece of tissue.
CFL Bulbs – Compact Fluorescent Lamps
Compact fluorescent lamps are better known to most of us as CFL bulbs. They are now a common sight, as virtually every home and business is using them to some degree. This is not surprising because, for many reasons, they are a far better lamp than the incandescent variety.
Fluorescent Lamps Last Longer
One advantage of using fluorescent lamps is they last a lot longer than standard household lamps. Many of these CFLs have a service life of 10,000 hours compared with 1,000 hours for the incandescent bulbs. As you can see they last 10 times longer.
Once they are installed you can virtually leave them until they need replacing. They are excellent for use in bulkhead lights especially those that are not easily reached. They greatly extend the period between setting up steps or towers for re-lamping.
There are many other advantages to fluorescent lamps especially if you have a lot of lighting to maintain.
CFL Lamps Save Time And Money
Another benefit is that they will save you as much as 75% off your current lighting costs. CFL lamps will also save you the time you would have spent replacing the unreliable filament lamps.
Having to change light bulbs can be very irritating when you are busy. This is especially true if you don’t have a maintenance man to do the work for you.
Energy Saving Lamps Reduce Overheating
CFLs generate far less heat than filament lamps and are therefore less destructive. A continuous buildup of heat in enclosed luminaires can cause cables and lampholders to become brittle and crack.
Because of the energy saving lamps lower operating temperature, this type of damage is greatly reduced. If cables entering the light fitting are sleeved and protected, there will be no damage at all.
CFLs – Replace With The Same Wattage As The One Remove
When you order CFLs (except bayonet and screw-in) always order the same wattage as the lamp you are replacing. There are several reasons for this.
Firstly, for some CFLs the plug-in lampholder is “slightly” different for each wattage. For the PL-C/E 4 Pin the 10W and 13W have a G24q-1 lampholder, the 18W a G24q-2 and the 26W a G24q-3. This only becomes apparent on close inspection and prevents the wrong wattage lamp being used.
Secondly, with some CFLs a higher wattage will mean a longer lamp. The PL-L lamps all have a 2G11 lampholder, have five assorted wattages and almost all of them are different in length. Obviously a higher wattage lamp may not fit into the light fitting.
Thirdly, by choosing a higher wattage it may damage the electronic ballast inside the light fitting. A lower wattage could mean it will not work at all.
The advantages of CFLs are, they will save you time and money. Below you can find out about the benefits and details of each lamp.
2D Lamps 2 and 4 Pin
The 2D lamps in 16W, 28W and 38W are available with 2 pins and 4 pins in colour 3500K. The 2D lamps are made in three sizes so they fit comfortably into small, medium and large bulkhead lights.
The 16W and 28W are frequently used in disc shaped luminaires, to light stairwells and corridors in commercial buildings. They are also the perfect shape for use in shallow light fittings that are used for low ceiling applications. The shape of the 2D lamps ensures that even at low level they will provide a good even spread of light.
The larger 38W lamp is generally used in the big square more functional bulkhead. You will see these in areas where practicality is more important than appearance. This could be basements, boiler rooms, storage rooms or underground car parks. The powerful 38W 2D lamps are very effective at lighting up this kind of environment.
They are easy to fit or remove by either pushing in or pulling out of the GR8 or GR10q lampholder.
PLS 2 and 4 Pin Fluorescent Bulbs
The PL-S (2 pin) and PL-S/E (4 pin) is available in 5W, 7W, 9W and 11W with a G23 and 2G7 base. They are one of the smaller fluorescent bulbs, so ideal for use in secondary lighting applications. The extra low wattage makes them very economical to use.
You will find them in brick lights, staircase lights and emergency lighting signs. They can also be used in small PL downlighters to light medium sized rooms.
These fluorescent bulbs are also available for a range of special uses. They include a germicidal version for pond filter and photochemical applications. A blacklight blue version for the detection of forged bank notes. And, a blacklight for use in the hygiene industry where they are used in fly killers.
PLC 2 and 4 Pin Low Energy Bulbs
The PL-C (2 pin) and PL-C/E (4 pin) are made in 10W, 13W, 18W and 26W. They are probably the most popular of all the plug-in low energy bulbs. They are short, slim and bright, making them the perfect lamp.
Where applicable you can easily fit two of these lamps into a medium sized bulkhead light. Because of this, they are a favourite with manufacturers who install them in a wide range of luminaires. They are frequently used in circular, square and rectangular bulkheads.
They are also used in commercial downlights and even space restrictive picture lights. They are very versatile low energy bulbs for use in residential, office, airport, restaurant and hotel applications. To use these lamps make sure your light fitting has one or two of the G24d or G24q lampholders.
PLL 4 Pins In Line – Low Energy Light Bulbs
The PL-L (4 pin) low energy light bulbs come in 18W, 24W, 36W, 40W and 55W.
They have the same output as fluorescent tubes of the same wattage, but are less than half as long. Also, they are far more streamline than the U-shaped fluorescent tubes. This makes them suitable for a wider range of applications.
Their length of between 217mm and 533mm makes them ideal for small and large light fittings. The shorter of these PL-L low energy light bulbs can be used in rectangular bulkheads to ensure a good distribution of light.
The longer 40W and 55W versions have been designed for use in specific luminaires. These include linear and 600mm x 600mm recessed and surface modulars. We are all familiar with these, they are very commonly used in drop ceilings in office blocks.
To use the PL-L low energy light bulbs, you will have to make sure the light fitting has the 2G11 lampholder.
PLT 2 and 4 Pin Energy Efficient Light Bulbs
The PL-T (2 pin) and PL-T/E (4 pin) are available in 18W, 26W, 32W and 42W. They usually have hexagonal shaped bases with a triple turn of fluorescent tube. The 4 pin base will stop the 2 pin lamp accidentally being installed.
These energy efficient light bulbs are about two thirds as long as the PL-C and PL-C/E lamps of the same wattage. This means they are able to concentrate light output to a small area for specialist applications. They are perfect for use in high performance PL downlights where extra light is needed.
The 32W and 42W provide that bit of additional light that other compacts cannot. They are the two most powerful of all the compact lamps. These PLT energy efficient light bulbs can only be used in luminaires with GX24d and GX24q lampholders.
PLF 4 Pin Fluorescent Light Bulbs
The PLF (4 pin) fluorescent light bulbs are made in 18W, 24W and 36W.
That’s three different wattages, each lamp with its own individual dimensions. That means they will comfortably fit into mini, square or rectangular modular luminaires. They are also used in downlights, uplights and luminaires that need that extra low profile.
The PLF fluorescent light bulbs have a very unusual shape so are instantly recognisable. The shape, which is like no other, allows them to be used in special application lighting. They have two loops of fluorescent tube mounted side by side and two pairs of pins in the base.
They are widely used in hospitals, airports, hotels and many other public buildings. These fluorescent light bulbs can only be used in lighting with the 2G10 lampholders.
Fluorescent Tubes In All Sizes
Fluorescent lighting is one of the better ways of illuminating a room. Fluorescent tubes will light up a room in a way that no other light bulbs can. They will provide an even spread of light without casting any shadows.
There are several shades of white that will light any area in exactly the way you want. The shades range from a warm yellow to a bright white. Standard white (835) and the brighter cool white (840) are the two most popular in the range.
The fluorescent tubes in this guide fall into four categories and they are T12, T8, T5 and T5 Miniature. The T stands for Tubular and the number stands for how many eights of an inch they are in diameter. The T12 is 12/8 (38mm) of an inch, T8 is 8/8 (26mm) of an inch and the T5 5/8 (16mm) of an inch.
However, this should not concern you too much when ordering them. Your focus should be on the wattage as this will determine the length and diameter of the tube. Whatever wattage you are using at the moment is the one you should re-order.
It is surprising how many people order fluorescent tubes by the length. This is wrong. There is only one way to order them and that is by the wattage. If you order a different wattage to the one you have, the tube will be either too long or too short for the light fitting.
When selecting tubes, always look at the wattage first, as this will define its length and diameter. The wattage will determine whether its a T12, T8, T5 Miniature, T5 High Output or T5 High Efficiency tube. In most cases, the wattage will tell you everything except the colour.
I have listed four fluorescent tube groups below –
T8 Fluorescent Tubes (26mm)
If you look up and have fluorescent lights above you, they probably contain T8 fluorescent tubes. T8 tubes are, at this moment in time, the most common of all the fluorescent tubes. They were originally made with a choice of halophosphate or triphosphor gas, but are now only made with the latter.
Halophosphate faded over time and light output was slowly but surely reduced. Triphosphor tubes will emit the same level of light right throughout their working life.
They are available in four wattages including 18W, 36W, 58W and 70W. They have a G13 cap on either end, each with two pins that are 13mm apart. The life span of T8 fluorescent tubes can be as much as 20,000 hours which makes them very efficient.
They are also made for a range of specialist applications. Specialist tubes include SAD, Grolux, Gourmet, Germicidal, Blacklight and Shrinkwrapped.
T5 Fluorescent Tubes (16mm) HO And HE
The triphosphor T5 fluorescent tubes are very energy efficient. This makes them ideal for lighting large open office space.
They are available in High Output and High Efficiency versions. Both of these T5 fluorescent tubes will allow you to use fewer watts than a T8 tube for the same or more light.
The High Output (HO) 16mm tube of equal length to a T8 tube will produce as much as 50% more light. However, its important to remember that they are usually a slightly higher wattage. Nevertheless, you will get more lighting for less energy.
The High Efficiency (HE) 16mm tube will emit the same light as a T8 tube but will burn 20% fewer watts. The benefits of using T5 fluorescent tubes quickly becomes apparent. If you use a lot of these T5 tubes, there is going to be a huge saving on your electricity costs. That makes them very popular for new lighting installations.
The High Output are available in 24W, 39W, 49W, 54W and 80W. The High Efficiency are available in 14W, 21W, 28W and 35W. The tubes have a G5 cap on each end with two pins positioned 5mm apart.
They have a long life span of 24,000 hours which is longer than most other tubes. The colours include 830, 840 and 865.
T5 Miniature Fluorescent Tubes (16mm)
The T5 miniature fluorescent tubes are a small range of very short lamps. There are only four in the group and the longest is 21 inches.
They are designed for use in places where space is limited. This could be emergency lighting, illuminated signs and sometimes picture lights. You will also find them built into furniture such as bathroom cabinets, mirrors and wardrobes.
For the smallest tubes, the lighting is very low but that is often all that is required. The wattages include 4W, 6W, 8W and 13W. The length of the tubes are 6 inch, 9 inch, 12 inch and 21 inch.
These tubes also have G5 caps, each has two pins with a 5mm space in-between. The average life span for T5 miniature fluorescent tubes is about 10,000 hours. There are a limited number of colours and they are white and cool white.
T12 Fluorescent Tubes (38mm)
The T12 fluorescent tubes should be at the top of the fluorescent tube section, but I have put it at the bottom for a reason. If I tell you that T12 lighting technology is 70 to 80 years old, you quickly realise it is well and truly obsolete.
However, it may surprise you to know that the T12 tubes are still available if you know where to look. They are expensive so you should consider replacing them with T8 tubes.
The T8 tubes will fit into the T12 lampholders because both tubes have a 13mm space between the cap pins. You can use T8 replacements for the T12 2ft, 4ft, 5ft and 6ft but not the 8ft. If you have 8 foot fluorescent lights and you cannot get the tubes, you will have to change the light fittings.
The T8 is a slightly lower wattage than a T12 of the same length, but you will notice little difference in light output. The T8 also has a life span of 20,000 hours compared to 10,000 hours for the T12 tubes. The T12 fluorescent tubes are powered by the old inefficient magnetic ballasts, but they will run the T8 as well.
In the UK, magnetic ballasts will run T8 tubes as long as they have a starter switch in the circuit. Starterless magnetic ballasts are designed for use just with T12 fluorescent tubes. These magnetic ballasts are no longer installed into luminaires but available as spare parts only.
Converting to the T8s will mean cheaper tubes, less power consumed and twice the life span. This makes the T8 tube far more energy efficient and economical to use. By changing from T12 tubes to T8 tubes or new T5 lighting, you should make savings of between 40% to 50% every year.
T5 Tubes, T8 Tubes And T12 Tubes – What You Should Do About Them
If you are keeping your T12 light fittings, you should re-lamp them with T8 tubes. As I said above, you can replace T12 tubes of 6ft and below with T8 tubes but not the 8ft.
If you have T8 lighting, at this stage there is no need to change to the better T5 lights. The T8 tubes are still viable technology and will remain in use for the foreseeable future.
Although LED will eventually replace all fluorescent that will not be for some time. When they do, there will be LED T8 and T5 tubes to fit your existing light fittings.
However, when first introduced, like all technology it is usually quite expensive. Manufacturers tend to be in a hurry to recover their research costs. Over time prices will drop and they will come within the reach of most people and companies.
Light Bulbs UK – The Different Types Of Light Bulbs Online
For now, that concludes the light bulbs UK blog post illustrating the everyday lamps in use. I have listed just some of the different types of light bulbs online and available from Cannon Electrical Supplies.
You should have learned a lot about the most popular lamps in use today. Found out about the benefits of the new lamps as well as the old. Learned how you can easily adapt low voltage light fittings to accommodate the new LED lamps. Also, picked up a few do’s and don’ts to make your lamps last that little bit longer.
I hope you have found all the information both interesting and useful. Why not share this post with your Facebook, Twitter and Google Plus followers. And, any observations you have will be more than welcome in the comments below.