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Energy saving light bulbs – turned off by slow light-up times?

Energy saving light bulbs

Are you turned off by the sluggish light-up times of energy saving light bulbs? Our latest lab test results suggest that this problem may be fading, but it all depends on how good the bulb is.

The most common type of energy saving light bulb, compact fluorescent lamps (CFLs), have been plagued by frustratingly slow warm-up times in the past – as many of you have shared in previous light bulb-themed Conversations.

The bulb in my bathroom is one such excruciating example. During the mini-test I conducted last night, it was over a minute before it emitted anything more than a dull orangey light.

Our rather more scientific, lab-based test findings, however, do make for better reading. The top performing CFLs are brighter, able to withstand being switched on and off 30,000 times and give out a fair amount of light immediately after start-up.

LED bulbs still king

During our tests, we checked how bright the bulbs were when first turned on, and then at intervals to ensure measured brightness met what was promised on the packaging. Our Best Buy CFL light bulbs didn’t drastically dim after 5,000 hours – the equivalent of five years’ use – and emitted good levels of light.

Start-up times still aren’t great, though. The worst performer emitted no light at all after three seconds. And even the best CFLs only achieved less than half their claimed brightness when they were first switched on.

For instant bright light, you’ll need to turn to more advanced LED lighting – but be prepared to pay a premium for it.

How much for a light bulb?!

The two LED light bulbs we tested were in a league of their own when it came to efficiency and providing immediate light.

But you’ll have to shell out at least £20 – and for one, nearly £40! – to bask in the LED radiance of these bulbs. Energy efficiency savings aside, that’s a lot of upfront cash to shell out on a single light bulb, particularly when we’ve become used to the likes of cheap ‘three-for-a-pound’ supermarket offers.

Your light bulb bugbears

Overall, it looks like energy saving light bulb technology has improved and it’s good to see more candle and rounded bulb-shape varieties available too.

Yet, as the next phase-out stage for 60W traditional light bulbs beckons, other small but significant daily usage problems remain for many of us – like the potential incompatibility problems posed by dimmer or timer switches, for example.

Personally speaking, until the price of LED light bulbs come down, it looks like I’ll have to wait for my CFL light to fully kick in after switching it on. Though I’ll certainly be pickier when I have to choose a replacement. Are you willing to pay more to enjoy instant, long-lasting light?

If you’re a Which? member, you can view the full test results of our Best Buy light bulbs here.

Derek sayers says:
8 July 2011

We have put up with fluorescent tube lights for over 60 years with their “white” light, slow starting, flickering etc. so what makes these new lights different?

Two things:

1) we had a CHOICE about where to put fluorescent tubes, we were not forced to have them in every place we needed a light

2) They use more reliable technology (which is necessarily larger and more expensive hence won’t physically fit into CFL’s and cost more than users would be prepared to pay for every fitting) and therefore start faster and deliver better light.

Peter says:
8 July 2011

I have to agree with Paul earlier on LEDs especially as GU10 format. I have tried different manufacturers and different configurations from < 1W upwards and they are distinctly unreliable. The expense of buying them plus that involved in making them, shipping them and then getting only a few months of use before they fail, make them the least green and most costly option available. The LEDs deployed in vehicle 12V systems seem to work much more reliably so either AC or higher voltage appears to be the problem.

I think you’ll find it’s the AC that’s the greater problem: LED’s are 2 volt (yes TWO volts) DC devices and to make them work on AC some sort of rectification and voltage drop is required. The cheapest way to achieve this (and also the most compact) is the use of capacitors but that’s also a fairly ineffective (note ineffective rather than inefficient) and prone to failure, especially when powered for longer periods.

It would be very cheap still and also suitably compact to achieve the rectification using diodes (more reliable as designed for the job) but to achieve the voltage drop more effectively would require bulkier, heavier, components that would not fit into the light bulb ‘capsule’ and would also be quite expensive.

I’ve not used any LED floodlights yet, so I’ve not opened one up to see what’s inside, but it would be very easily possible to fit suitable components into the case of a floodlight and the price that is charged for them makes me think it is at least possible they have such parts inside them.

Cars don’t need the rectification because their electrical systems are battery driven so that’s DC to start with and the voltage drop is far smaller and can be achieved much more easily and reliably with resistors or the creative use of circuits.

I have twelve, relatively new and expensive, wall lights in my house that each take two small golf ball lamps. I have been unable to find any low energy bulb that is small enough for these fittings – they all look ridiculous because they are so large. I really object to being forced into wasting money and time replacing these wall lights because of a totally unecessary ban on traditional bulbs. So I am doing what loads of others are doing – stockpiling old lamps to delay changing the lights – hopefully until either small golfball LEDS are available (and cheap) or the government sees sense.

TT says:
10 July 2011

Couldn’t agree more with John. I too have old fashioned but tasteful light fittings. They fit in with the classic decoration. The tungsten light bulbs were twisted and pearl. The new light fittings are neither shaped the same as those tungsten bulbs they are replacing nor are the right size. Until someone consideres all taste and not just a bland dumbed down EU standard I am afraid that I will continue to stockpile tungsten lights that fit with the decor until they disappear. Before anyone suggests that I am not doing anything for the environment, I have taken many more drastic steps to reduce my family’s carbon footprint that is far more effective than a few light bulbs. Upgrading house insulation, reducing the in-door temperature and reducing the use of a car by 80% surely contributes more to environmental impact.

Ted says:
8 July 2011

Some years ago, I asked Which if it would be feasible to include whether a particular bulb could be used with a normal dimmer switch, which they do sometimes now, and also to tell us whether it can be used with a time switch (which requires a very small current to pass through the filament all the time.).

1. Using a dimmer is part of my contribution to saving energy.
2. Using a time switch is part of my home’s security system.

I ask again: Will Which please include this information in its reviews of bulbs?

Brian Kilbey says:
8 July 2011

I enjoy boring the young by telling them that waiting for the bulb to ‘warm up’ is just like waiting for the mantle to warm up in the days of gas lighting.

I’ve been using tungsten bulbs for nearly sixty years. They cost very little to buy and very little to run. More importantly, they haven’t caused the world to stop turning in all that time.

Now, because of the ‘global warming brigade’, we are being made to buy what many see as an inferior product, whilst China opens a new power-hungry, carbon dioxide-emitting factory every day (or so they say).

I think it’s time we put things into perspective. If it ain’t broke, don’t fix it.

They cost very little to buy and very little to run.

I’m not sure that many people would agree that conventional light bulbs cost little to run.

Paul says:
8 July 2011

I’ve been using so called longlife energy saving light bulbs in places where I can live without instant light for the last 3-4 years.
Every where else I still have incandescents.
Guess which bulbs fail on a regular basis——-that’s right, the long life energy saving bulbs.

Real Skeptic says:
9 July 2011

Nice anecdote there, but it isn’t scientific. You are explicitly dealing with different demands on the bulbs and have no standard against which to measure endurance of the bulbs. Perhaps you have the CFL bulbs on more? A different temperature range? Different quality of bulbs selected? There are simply too many unquantified variables to make any valid comparison of failure rates between the types of bulbs.

Real Skeptic’s post is, I suppose, technically accurate but comes over as derogatory to Paul and all those like him who share this experience.

Whilst Real Skeptic makes a valid point about too many variables, there are also too many people who share Paul’s experience (again in too many situations to make it scientific) to ignore the fact that these energy saving lamps, which are more environmentally polluting than tungsten lamps in manufacture and disposal, in general do not have the life span that is claimed.

This means that the way in which the pollution caused in manufacture and disposal is justified (i.e. it will overall be the same as or less than that from tungsten lamps because fewer will be needed) is at least flawed if not downright dishonest.

It is a similar situation to a great many other “energy saving” products which in some cases actually use more enrgy than what they replace but in almost ALL cases, when manufacture, disposal and on-costs such as replacement parts are considered, are actually worse than what they replace.

The reason this often goes un-noticed, and is sometimes challenged hotly by people who want to “prove” the energy saving devices are “good”, is that everyone from the governments and EU parliaments downwards insists on only allowing very selective data to be published which makes a very unscientific comparison between products based on a minuscule selection of variables which make the argument look favourable.

In the case of CFL lamps the data used is the running cost (and sometimes the supposed potential life span, but always read the small print for the caveats about this) but the manufacture, import, and disposal costs, let alone any technical or health difficulties are never compared against tungsten lamps.

In other cases, for example boilers, it is again the running cost that is contrasted, but the fact that the boilers are now designed to last at most 10 years contrasted to older ones which lasted up to 40 years means that the end user (US!) cannot ever achieve the stated savings as they are consumed in on-costs and replacement costs and the environmental saving is equally unachievable due to the pollution caused by the manufacturer of more replacement parts and more boilers to keep selling.

None of this is anything new at all: it is the same old story of being able to use statistics to prove anything at all – and here (CFL’s) is another outstandingly good example of how statistics have been used to convince millions into thinking that CFL’s are “good”

Dave D, an excellent response to Real Skeptic and the subject in general.

Well Done Paul & JBR. I have stockplied Tungsten 40w. I use ‘jamjars’ long life, which are not and my LED in the bathroom exploded showering bit of glass into the bath. Fortunately no one was in it. These clip-on fittings are dreadful to use. They lightup delay is not disastrous, just get accustomed to it. I hope not to buy any replacements except LED for a few years.

Not sure of the comment about why buy energy saving bulbs when I end up paying the same as the price of energy has gone up… I’d rather be paying the same than more!

As to my own experiences of lower energy bulbs:

– I have just changed my first CFL in the 5 years that I’ve been in our current house. Not bad considering the number of Tungsten Filament and Halogens I’ve changed.

– I have had free, cheap and expensive types of CFLs. 24 in total (don’t ask me why they put 15 lights in a small hallway!) None have exploded, and I know of no one who has had one do it.

– of these, one or two weren’t very good at start up, but the best was a 10p one from Tescos about 3 years ago! Who’d thought it?! The one in our bedroom is suppossed to be a soft start, and we’re grateful for it.

– The colour balance of our CFLs seems ok, not too white.

– the only decent replacement I’ve found for standard dimmer circuit is the Halogen 30% less energy type. I have one Megaman dimmable, but it takes an age to get upto temp.

– the hardest thing I’ve found to replace were the 12v MR16s in the Kitchen, but 2 LED and 4 CFL GU10s are OK for the timebeing and saving a fortune. Still looking for wide beam non-flicker LEDs, but it’s early days.

Daiverse says:
8 July 2011

If you look on the very popular online maketplace you will find a pack of 4 gu10 LEDs for £12.80. I have replaced 12 x 50 watt halogens with these 3LED, 3 Watt, soft white bulbs which give out 300 lumens (not much less than the original halogens) I like the resulting light and I can use all of them at the same time and use less energy than one of the originals.

Daiverse, don’t keep me in suspense! Give me clue as to the make/seller on that popular market place.

Peter says:
8 July 2011

I too used the old jamjar lights in the 80’s. They were a horrible orange colour and took ages to warm up in the winter. The modern ones have a much better colour, are generally fater to start and cheaper. I found Ikea ones to be terribly unreliable – about 20% didn’t work from new and all failed very quickly (these were bought about 6 years ago – they may have improved since then). Some of the more expensive ones do light up faster – I use them in places where I need instant light like hallways.
I have a lot of wall lights and multiple ceiling lights, the small spirals fit well and don’t cause interference. I get them from QD who bizarrely sell 3 bulbs for less than they sell one of the same rating.
I tried one of the 230v halogen replacement led units about 3 years ago, it was too dim, 2 of the 30 or so leds failed after a month and the whole thing packed up after about 4 months. I ordered a variety of led bulbs from China on ebay about ten days ago; I am waiting to get them and will report on my findings. There is certainly no good reason the leds should be £20+, those I ordered varied from £3 to £10 incluing p & p. I don’t know how they wire mains leds but if all are wired one way they are likely to flicker strongly as each bulb will only light for half of the AC cycle. If half are wired in one direction and half the other, this won’t be a problem as they will work in “shifts” with half lighting when the live wire is positive and the othere half when it is negative.
Finally, I took my old cfls to the local recycling centre. They had to go in a container designed for standard straight tubes. Many of those already there were broken and 2 months later when I took some more my old ones were still there – so it seems they’re just going through the motions.

EMCman says:
8 July 2011

I’m a CFL convert (though it did take a while, for all the reasons above).
I now use Osram Duluxstar Mini Twist 23W spirals which give out light equivalent to somewhere between 100W and 150W tungsten, quite quickly.
I also use Philips Tornado spirals.
And I bought a Varilight Dimmable EnergySaver+ just a couple of weeks ago. Yes – DIMMABLE!
I replaced a 100W tungsten bulb with one of these beauties in a room with a dimmer switch – and it just works. OK, it takes a little less than a second to light up, but then it gives full output (or half or quarter – did I say they’re dimmable?) in seconds.
These are not the cheapest available, but nor are they expensive.
So to those of you who are so impatient that you’re prepared to go on burning 5 times the energy for the sake of a few seconds inconvenience, I say give these good quality bright modern bulbs a go – you may surprise yourself.

Now that’s useful, my Megaman dimmable CFL was brought about 3 years ago, and is ok if the lights are to be on for a while or part of a cluster, and you’re not going to be able to be able to read by it, it just isn’t bright enough.

But after 3 years, it’s still going strong, although in the front room and not the computer room, where it started of.

Jill from Leigh says:
9 July 2011

I have no problem with CFL bulbs. They are in every light fitting we have apart from the kitchen. Even in outdoor lights where sometimes the temperature is low. Now there are shapes and fittings for every type of fitting
Agreed, some are slow to brighten up, but sometimes that is rather nice, as in our lounge you switch on as dusk approaches and they seamlessly take over to replace daylight.
Everywhere else there is no problem – the ones we have in bathroom and toilet light up very quickly. Hall and stairs lights stay on after dark till bed-time, therefore good for safety, and cost very little to run.
They do last very well – we are still using those sent for free by energy companies some time ago, and they have been very satisfactory.
If we need a bright light for a specific purpose – reading, needlework etc. then e use a spot reading light – but that has always been the case. Surely room lights were never intended for that use anyway.

Quick research on LEDs came up with the following.

The US (?) regulators were going to insist that all LED were at least 150Hz, but US lobbyists got them to reduce it to 100Hz. This meant the manufacturers could reduce costs as they didn’t need to put extra components in their bulbs: 100/120Hz covers most of the worlds mains frequency when rectified. And as an earlier poster said: diodes cost little, especially when you already have some in your ‘bulb’ to start with – Light Emitting Diodes!

However, LEDs switch off after they pass a certain voltage, which means they are fully off for a certain length of time. This can result in strobeing, which is what I had with some bright, wide beam (100 deg!) LED lights that I had to send back: they were giving me headaches. You could even see the strobing effect by waving your hand quickly. Nasty cheap things. It’s even worse than the old 50Hz flicker of the old fluorescents as these at least had some persistence and were never completely dark between cycles, unlike the quick LEDs.

Now if the US had imposed it’s 150Hz, then Capacitors and the like would have had to have been employed, producing much better lights. But of course, this also gives the companies 2 bites of the Cherry: buy the nasty ones now, and the better ones later, even though your old ones still have 10 years to run!

You can buy good none flicker LEDs, but at a price, and it’s possibly the cost of the extra very high quality components that make up the extra cost of the lamps to get these components to last as long as the LEDs, just like you get in high quality computer boards.

As for the Halogen MR16s and GU10s, these should have been phased out before the standard bulbs were: they look great, work well in shop displays, but are rubbish in the home: bright light in the wrong place for too high a running cost. 300 Watts to run 6 in our kitchen, just to have a well defined shadow where I wanted to use any of the work surfaces? No thank you. But it’s style over substance and interior designers have a lot to answer for. Now we have 2x2W LEDs, and 4x7W CFLs in their place (straight swops, but without power wasting 12v transformers) and although the CFLs take a while to get up to temp, they produce as much light as a 35W GU10/MR15, but from
the full width of the bulb, producing a much better light to work with.

Of course, a couple of 5ft T8 fluorescents would have produced much better light without any hassle, but they’re just not ‘trendy’. But with BG putting its electricity prices up by 16% (and the rest to follow) I’d rather have the money in my pockets, much more trendy!

IanP says:
9 July 2011

I find it curious that there appears to be a total disregard of the research findings referred to in the earlier post by ‘Disappointed’ that ‘several carcinogenic chemicals and toxins were released when the environmentally-friendly compact fluorescent lamps (CFLs) were switched on, including phenol, naphthalene and styrene.’

Doesn’t anyone care?

It’s certainly enough to put me on guard and look for alternatives.

Phenol is caused by “Outgassing” of Phenolic circuit boards which are found in most household electronic devices. The only difference being the levels from CFLs are minute, when compared to those of a computer or TV.
As far as mercury is concerned . Incandescents are probably responsible for more mercury emissions than CFLs; burning coal for electricity emits mercury, and incandescents use much, much more energy. CFLs can be safely recycled without the mercury escaping into the atmosphere, and the mercury can be safely recovered.
Typical household CFLs contain less than 5 mg of mercury, which is a sphere about the size of the tip of a pen. CFLs do not emit mercury as they operate. The only way mercury could be emitted from a CFL would be if the outer glass tubing that contains the mercury were to break.
The following is taken from a US research document
“How much mercury do power plants emit to light a CFL?
About 50 percent of the electricity produced in the U.S. is generated by coal-fired power plants. When coal burns to produce electricity, mercury naturally contained in the coal releases into the air. In 2006, coal-fired power plants produced 1,971 billion kilowatt hours (kwh) of electricity, emitting 50.7 tons of mercury into the air—the equivalent amount of mercury contained in more than 9 billion CFLs (the bulbs emit zero mercury when in use or being handled).

Approximately 0.0234 mg of mercury—plus carbon dioxide, sulfur dioxide and nitrogen oxide—releases into the air per 1 kwh of electricity that a coal-fired power plant generates. Over the 7500-hour average range of one CFL, then, a plant will emit 13.16 mg of mercury to sustain a 75-watt incandescent bulb but only 3.51 mg of mercury to sustain a 20-watt CFL (the lightning equivalent of a 75-watt traditional bulb).
I wonder how many “Old” style thermometers are still being shoved under childrens tongues, they contain 500mg of mercury!

So as I said in a previous reply, if you really want to believe the exagerated claims for the “Deadly” CFL consider this: There are infinitely more dangerous electronic devices in the average household that contain significantly higher levels of dangerous substances to worry about than a CFL. Get rid of anything with a PCB and electronic components, anything that uses electric motors, anything plastic and replace them with wooden handled hand tools and a stack of candles.

john cross says:
9 July 2011

thank’s which,for sending me emails with comments on cfl bulbs.
if it works it dont need fixing, how right when l had to sit under the cfl bulb just to read the paper?
what worried me most,after 2yrs of sitting under a bulb that contains mercury,and emits ultra violet rays. thanks to the birmingham mail printing the facts,about these toxic bulbs,l would have been non the wiser. l would have been putting the tension over my eyes and the migraine attacks,down to getting older. its thanks to my dear wife,who helped me put 2 and 2 togeather,she could not understand,as a migraine sufferer why the attacks went from 1 0r 2 a week,to 7 days a week? now we are using incandescent bulbs again, l have no more tension or migraine and my wife only has the odd attacks. what happened to choice,and not forced into using something thats not fit for purpose.

Steve says:
9 July 2011

Which should be campaigning to give consumers a choice. If we don’t like the alterrnatives we should be able to stay with incandesant bulbs. Let us make the decesion about what we like rather than forcing us to accept someone elses argument.

David Gardiner says:
10 July 2011

In my house I have chandeliers with a total of 17 40W pearl candlle bulbs, all controlled by dimmer switches. For many years I could not replace these with low energy bulbs, as nothing would work with dimmer switches. The tungsten bulbs did not last long, and had to be replaced fairly often. However, in the last few months I have been able to get 28W=40W pearl BC dimmable candle bulbs, made in Slovakia by Osram GmbH of Augsburg. These are very satisfactory, they warm up quickly, and none have yet failed. Now I am unable to get any more of these because, I am told, under EU regulations manufacturers can no longer make pearl bulbs, and all have to be clear. Is this correct?

RogerW says:
10 July 2011

Many people (including one in this household) dislike the “cold” colour of CFLs. I only buy those giving low temperature (warmer) light. This should be shown on the package as a temperature in degrees Kelvin (K). From memory, around 2,700K is the best available.

Can Which? please quote the colour temperature in future tests?

RogerW: You are right that colour temperature should be shown on the package and mentioned in tests, though it might be useful to have a simple description. Fluorescent tubes used to be classified as warm white, white and daylight – which was easy to understand.

The CFLs that produce a cold light are much brighter, so there is a need for different types, depending on whether colour temperature or light output takes priority. A warm light is best in the living room, whereas for an outside light getting maximum brightness at minimum cost is what matters.

Just had a look at a couple of Scare Lines referencing Peter Braun and harmful chemicals from CFLs: it would seem very odd after decades of research, tests, and standard fluorescence bulbs that it turns out that they prove directly harmful. We’ll have to see how it plays out, but it doesn’t half smack of the Scare Lines we had over MMR; people read what they want to believe and dismiss overwhelming real evidence to the contrary.

If you want any evidence of such hipocracy; search out the old photos of the mothers with children standing outside school gates with placards demanding that the mobile phone towers are harming their children… Now count how many have fags in their hands. They’d believe a Scare Line about the phones, but insist the chemically toxic smog in their homes was harmless.

Only time will tell…