The lifetime of a LED lamp is defined in hours. As with all types of lamp, the light output very slowly fades over time. LED lamps do not generally burnout they will still perform after their rated hours e.g 25,000 hours.
The lifetime is the figure stated when the light output is predicted to drop by a significant amount of the original light output where you may consider a replacement, this is partly due the the slow aging of the parts of the lamps such as refractors and other components. External factors such as heat, humidity, switching cycles and power supply will affect the lifetime of an LED lamp.
The table below gives an indication and comparison with filament and CFL lamps on how many years a LED lamp rated at 25,000 hours will operate.
As you can see a LED lamp will last over 22 years (at 3 hours per day) against a filament lamp of less than a year and a CFL of just over 9 years.
The longer life of LED means less time spent on lamp changes (important for hard-to-get-at areas) . Also it's great for the enviroment with less lamps, packaging and transport energy being used.
All lamps including LED have a number of switching cycles. This is the minimum number of times the bulb can be switched ON and OFF before failure in normal use, lamps may go on to last longer. For a typical value of 12,500 the lamp can be switched ON and OFF once a day for a minimum of 34 years! (Environmental factors such as temperature can affect the value). In general, LED lamps for home or office use are not designed to be switched ON and OFF rapidly.
With LED lighting, especially spotlights you may have the option to choose the "light colour", known as " (Correlated) Colour Temperature (CCT) ". Two examples are "Warm White" and "Cool White". There are no rules - the choice is about personal preference and use. CCT is expressed in Kelvin (K).
Fitting an LED bulb is the same as fitting any other bulb – but you will have to do it less often!
Before you change a bulb please ensure you have a similar LED replacement with the same base fitting, shape and light output.
Before changing or inspecting a bulb always turn OFF the power at the mains. Please take the necessary precautions if working at height. Wait for the current lamp to cool if required. Carefully remove the current lamp making sure you keep safe any clips or fittings. Fit the new LED lamp and switch the power ON and think about the energy savings you are making when compared to a conventional lighting. Sometimes a new light source may take a couple of days to get used to.
Lamps should be changed by a competent person. Please contact a qualified electrician if in doubt or to make any additions or changes to your circuit.
Dispose of old bulbs responsibly, especially CFL lamps that may contain mercury. Bulbs are not normally disposed of into the normal domestic or commercial waste stream, if in doubt check with your local authority.
When using LED bulbs with dimmers that have been produced for conventional lamps - there can be a mismatch in technology, that can cause issues like flickering; Your existing dimmer may have been designed to dim high-power circuits, whereas LED lamps are low-power products. You should change your existing dimmer for a dimmer designed to work with LED.
Will using energy-saving light bulbs save me money? Replacing just one 60W incandescent with a CFL bulb (the most common style of energy-saving light bulb) can reduce your electricity bill by around £7 a year, so replacing 10 light bulbs with energy-savers could save you £70 a year. LED bulbs are even more efficient than CFLs and save almost £7.50 per bulb per year. LEDs usually cost more to buy initially but have incredibly long life expectancies, so you may not need to replace them for up to 30 years. Halogen bulbs are the least efficient, so you’re unlikely to notice any reduction in your energy bill.
Lighting accounts for 18 per cent of a typical household’s electricity bill. You can cut your lighting bill and energy use by changing which bulbs you use and how you use them. Houses typically use a mixture of standard light fittings and downlighters or spotlight fittings. Energy efficient bulbs are available for both types of fittings.
Which light bulbs are energy efficient?
There are two main types of energy efficient light bulbs available in the UK. Compact Fluorescent Lamps (CFLs) and Light Emitting Diodes (LEDs).
CFLs are a cost-effective option for most general lighting requirements. Replacing a traditional light bulb with a CFL of the same brightness will save you about £5 per year, or £70 over the lifetime of the bulb.
LEDs are available to fit both types of fittings and are particularly good for replacing spotlights and dimmable lights. They are more efficient than CFLs and will save you more money in the long term. By replacing all halogen downlighters in your home with LED alternatives, you could save about £35 a year on your electricity bills.
What else can I do to save energy?
You can save money and energy by implementing control mechanisms and being conscious of how you use your lighting.
Always turn lights out when leaving a room, regardless of how long for.
Be conscious of how many lights you have on and whether they all need to be in use.
Arrange light switches so that its convenient to turn them off i.e. place switches at top and bottom of stairs, each end of a hallway and each door to a room.
Use a sensor and timer on external lights so they are only in use when they need to be.
Use appropriate lightings i.e. a low back ground light while watching television and a bright, concentrated light for reading. Having a range of lights in a room with separate switches will make this easier.
Review of old and new lighting technologies
Low energy lighting is becoming the norm as inefficient bulbs are phased out. Energy efficient lighting technology is developing quickly and a range of products are now available to choose from.
Traditional light bulbs
Traditional light bulbs, also known as tungsten filament, incandescent or GLS (General Lighting Service) bulbs were invented more than 100 years ago and are extremely inefficient. Only about 5 per cent of the electricity they use is converted into visible light. The filament is heated up until it glows giving off a yellowish white light. The bulbs do not last long because the filament gradually evaporates.Halogen light bulbs
Halogen light bulbs also use filament technology but run at a higher temperature making them slightly more efficient than traditional light bulbs. They are mainly used in spotlight fittings. Though more efficient, they are often used in large quantities, increasing the total electricity used to light a room.
The EU Commission started the phase-out of D and E-rated bulbs in September 2013.
Often rooms with halogen spotlights are brighter than they need to be so you may be able to save money by installing lower output bulbs. LEDs are an excellent energy efficient alternative.
Compact fluorescents (CFLs)
CFL technology uses gas inside a glass tube which is charged with electricity until it glows and gives off light.
They use about 75 to 80 per cent less electricity than equivalent traditional bulbs and can last up to ten times longer. They are available in a variety of shapes, sizes, colours and ranges of colour rendering capacity
CFLs are great for replacing standard home light fittings. Spotlight bulbs are available but not widely and tend to be more expensive - LED spots are a better option for this.
Strip lights or Linear Fluorescent Lamps (LFLs)
Strip lights use the same technology as CFLs but the tubes are shaped longer and flatter. They are more efficient, faster to light up and emit a better quality of light than traditional strip lights.
Strip lights are not often used in homes but can be a good choice for places where bright light is required, such as in kitchens or above bathroom mirrors. A modern slim tube fitted in a good reflector mounting is the most efficient option.
LEDs are simple solid state electronic devices that allow electricity to flow through them in one direction to produce a small amount of light.
Bulbs for domestic use contain a large number of LEDs so that a bright enough light is emitted. LED replacements are available for most light fittings, and are particularly suitable for replacing spotlights and dimmable lights and more and more options for LED main ceiling bulb replacements are coming on to the market.
LED prices have come down a lot over the last few years and now offer the best value for money.
Light fittings and shades
A dark lamp shade can absorb more than half the light a bulb emits which can reduce the efficiency of your lighting. You can save energy and money by using transparent shades or fittings that you regularly clean.
Light fittings with a reflective inside can increase efficiency if concentrated, directional light is required. Spotlight fittings often have this reflective inside. Halogen spotlights and LEDs do not require a reflective fitting as the reflective surface is incorporated into halogen bulbs while LEDs give out directional light by default.
Some light fittings are designed to be used with CFLs only, however the tube-only CFL that you need for these fittings is more expensive by comparison to ordinary CFLs.
What about the phase out of inefficient light bulbs?
All traditional incandescent bulbs have been banned within the EU, as part of a shift towards more efficient technology and by September 2016 some of the least efficient halogen bulbs will be banned, with other lower performing halogens expected to be banned by 2018. An increase in efficiency and decrease in the cost of LED bulbs over the last few years has helped ease this transition.