Energy Saving Light Bulbs

jonisin

merdekaorang1125 wrote:

Thank you for the tip. I have to visit the town near here with a Waitrose today so will call in and meet all the Martin's Moneymatters subscribers fighting over the last few... Seriously, though, folks: a (now late) friend - a chemistry BA - once did some research on energy saving light bulbs and, he told me, it takes fifteen minutes from switch-on before you start any saving i.e. the cost of powering it up is more expensive than a conventional bulb's. So, fit them by all means but not in areas where lights are on for very short periods. Good places would be kitchens where you are working for long periods, outside-the-door lights - but not PIR activated (not sure if they are suitable), unless you have the timer set for more than 15 minutes (don't do that anyway) - landings, porches, passageways etc. Just think it over before installing one in any particular area. After all, you know your habits best. Hope this is useful.

I very much doubt if this still applies if it ever did. I have been told on more than one occasion that the startup costs are in seconds and they SHOULD be switched off when the room is not being used. I have been told that these energy saving bulbs are better than the earlier ones, my 6 year old ones deteriorated over time as in the light they emitted became dimmer.
On a similar subject I have seen many people say the same with flouescent tubes (strip lights) and again they SHOULD be switched off when not in use. If people want to leave them on thinking that it will cost them more to switch off and on again shortly afterwards then they will be missing out on savings which is the whole point of the exercise.

Perhaps someone in the industry should clarify all this so that heresay isn't continually bantered about confusing everybody.

withabix

merdekaorang1125 wrote:

the cost of powering it up is more expensive than a conventional bulb's.

Sorry, that logic doesn't work.

A conventional 60 watt light bulb produces 60 watts of energy in the form of light and heat, from the moment you switch it on, due to the resistance of the wire filament. Conventional lightbulbs are 100% efficient if you want heat and light!

An 11 watt low energy bulb produces 11 watts of energy, mainly in the form of light with some in the form of heat, although they never get more than slighlty warm and that's probably heat generated by the starter.

For an 11 watt low energy bulb to use more energy that a 60 watt bulb for the first 15 minutes, it would have to use more than 60 watts, which it doesn't. If it did use 60 watts, it would be 6 times as hot as an ordinary lightbulb or 6 times as bright!! (assumes no losses).

Maybe that's why your late friend had a BA in Chemistry and not Physics.

withabix

mellis4148 wrote:

Just be aware that energy savings are non-existant when used in a thermostatically controlled environment as the reduction in erergy used by the bulbs will be offset by increasing the energy used by the heating system.

Depends if you are trying to keep the room warm or cool! For the latter, savings will be even higher!

builderbob_3

I was buying these by the case from Netto and then selling them on ebay and doubling my money. The 18w cost 47p and the 11w cost 49p, and I was slling them for a £1 each plus delivery!
The exact same Philips Genie bulb in argos is/was £3.99.

What is it they say about a fool and his money!!!

Dave_in_Andover

Hi,

Yes, please buy and use low energy bulbs. BUT, we have tried some of the cheaper brands, and those sold by major diy chains - but they seem to be made in the far east and DO NOT LAST AS LONG as those from the Big Name companies.
We now only buy the Philips, GE etc brands, and look for those made in Hungary, Poland, Germany or the EU.

Hope this is of use.

New Years Resolution- Switch off EVERYTHING that's left on "Standby".....:beer:

Peter13B

Yesterday I got a pack of 3 Osram 21w (100W) bulbs for £2.99, it was a special deal.

browolf

there's a shop near me called home bargains or something like that; selling osram 11w bulbs for like 59p!

Dustsucks

merdekaorang1125 wrote:

... he told me, it takes fifteen minutes from switch-on before you start any saving i.e. the cost of powering it up is more expensive than a conventional bulb's. So, fit them by all means but not in areas where lights are on for very short periods. ....

Just out of interest, I ran a quick check on a variety of bulbs from the oldest of the original Phillips SL25 with the transformer in them through to the latest varieties and without exception the energy consumption remained almost exactly constant over the 15 mins. or so that I ran them. If anything, it increased very slightly but the biggest difference was the light output. The earliest bulbs had a noticeable delay before producing any light and increased slowly over the next 5 minutes or so. The newest ones are almost instant and also come to full brightness almost immediately.

The newest ones are much more efficient than the old ones, almost as good light-wise as a standard bulb and last much longer but it is worth noting that some are better than others and some are rated at 15,000 hours while others are only 5,000 hours - read the box - cheapest isn't always best!

Garetha

merdekaorang1125 wrote:

...it takes fifteen minutes from switch-on before you start any saving i.e. the cost of powering it up is more expensive than a conventional bulb's. ....

out of date advice
I searched and found this:

Is it better to turn lights off when you leave the room? I heard somewhere that it uses more energy to turn lights off and on than to leave them running.

That used to be the case with fluorescent lights, but advances in technology, especially in ballasts, have resulted in lights that do not use appreciably more energy to start up. Turning fluorescent lights on and off does slightly shorten the lifetime, in hours, of the bulbs, but you will have to replace the bulbs less frequently if they are not running all day long. Incandescent lights do not require additional energy to start, in any event, so if you are leaving the room for more than a couple of seconds, you will save by turning the lights off, for both fluorescent and incandescent bulbs.

needaspirin

I bought some from Poundland. After many hours of use one of them went off with a bang that put out my lights and melted the plastic. I sent the following message to Poundland via their website on 31st october and again on 8th December. I included my address, email etc.

To date I have been ignored

Dear Sir or Madam,

I would like to draw your attention to a potential danger from your energysave lightbulbs.

One of the Poundland energy saver lightbulbs that I installed recently went off with a loud bang and a flash that took out all the other lights in my house. When I examined it I found that it had partially melted and sooty deposits were around the tubes.

This worried me as I leave a light on when out and at night while sleeping and think this could have caused a fire. I wonder if there is a common fault with Poundland 2U 7W 6400k bulbs?

After re-setting the safety circuit breaker in the fusebox (thank God I had those installed) all lights operated correctly including the socket that had held the offending bulb.

I welcome your response,