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Energy saving bulbs - dim or what!

David Jenkins - 25/9/08 at 07:50 PM

I recently received a couple of energy saving light bulbs from my electricity supplier - one is supposed to be equivalent to a 60W bulb, the other to a 75W bulb.

Is it just me, or are these bulbs really dim? Even when you allow some time for them to warm up properly, they cast a very gloomy light that's nowhere near as bright and cheery as the filament bulb they replaced.

I reckon that the '60W equivalent' is about as bright as a 40W filament bulb...

MikeRJ - 25/9/08 at 08:26 PM

I'm sure the ratings are very optimistic, and some of them can take quite a long time to reach full brightness.

They also don't seem to last very long, I've replaced several already that have barely outlasted filament bulbs.

smart51 - 25/9/08 at 08:28 PM

I always buy one size up as they are optimistic about the comparisons. You're still saving a lot of power as you might need an 11W bulb rather than a 9W one to be as bright as a 100W incandescent.

David Jenkins - 25/9/08 at 08:37 PM

The one place where we have filament bulbs running for quite a time is in the kitchen - we've got six 50W GU10 downlighters. The energy saving equivalents are Ł9 each minimum, for decent brands from the cheapest on-line supplier I could find...

But, even so, that makes 66W instead of 300W, which is significant when the lights may be on for hours at a time in the winter. Trouble is, they are 18mm longer than the filament originals.

The rest of the house has energy-savers for every bulb that may be left on for significant amounts of time. I haven't bothered to change bulbs where they are only switched on for a minute or so - by the time they warm up enough to give decent light, they'd be switched off again!

[Edited on 25/9/08 by David Jenkins]

Mr Whippy - 26/9/08 at 08:09 AM

all my lights are energy saving, I love the way they take a while to heat up as I hate being blinded in the morning. I have had to replace 2 in four years out of around 20 odd bulbs which I think is very good. I have a few 5w ones in the hall that I can't even be bothered turning off seeing how little they use. Old fashioned bubs have no place in my house at all, there banned

Macbeast - 26/9/08 at 08:20 AM

Can't stand them. You go into the bedroom to get something and you're back out before they know you've switched them on

JoelP - 26/9/08 at 10:23 AM

i find night vision goggles to be far more efficient.

Just a shame the house is so damned cold now.

greglogan - 26/9/08 at 10:40 AM

quote:

The one place where we have filament bulbs running for quite a time is in the kitchen - we've got six 50W GU10 downlighters. The energy saving equivalents are Ł9 each minimum, for decent brands from the cheapest on-line supplier I could find...

I run an electrical wholesalers in Ireland. We can supply 7W Gu10 CFLs which are the same height as a GU10 lamp. These are tried and tested by us for over 2 years now. We have one on display here from 8am to 6pm 5 days a week - hasn't been replaced yet. Although they are not from a mainstream supplier, they are proven by us to work - otherwise I wouldn't allow them to be sold here. Prices is around €7 or Ł5.50. Equivalent to about a 30-35W lamp.

A new one just arrived from a different supplier and as yet untested (same height) is an 11w CFL Gu10 lamp going for about €9 or Ł7. Claims of around 50-60W equivalent.

Hope this helps!

Greg.

Mix - 26/9/08 at 04:23 PM

Hi

Is there any truth in the rumour that energy saving bulbs have to be left on for about twenty minutes before making any saving over normal filaments? The inference being they use quite a lot of energy in the start up phase.

Regards Mick

Mix - 27/9/08 at 02:09 AM

Hi

After a bit of searching I found this

Can I use a CFL in applications where I will be turning the lights on/off frequently?
Compact fluorescent light bulbs work best if they are left on for over 15 minutes each time they are turned on. These types of lamps can take up to 3 minutes to warm-up. Warm-up will probably not be noticeable from a user stand point, but the lamp needs to warm-up in order to reach the point of most efficient operation. Frequently switching them on and off will shorten the life of the product. If the life of the lamp is shortened significantly, you will not reap the financial benefits (includes energy & life of lamp), that are common to CFL lamps.

So possibly not beneficial in some applications, (bathrooms, toilets, wardrobes etc.)

Regards Mick

greglogan - 27/9/08 at 07:24 PM

Mythbusters tested this (so it must be true....) about wether or not you had to leave a flourescent type lamp on for a protracted period of time to reap the benefits or wether or not it used up 30mins of electricity to start the lamp.

They reckoned the myth was busted, but I think it depends on wether or not use an electronic ballast (straight on) or a switch start ballast (wirewound - flick,flick,flick,lamp on). The electronic type ballast (as used in all modern CFL type lamps) is hugely more efficient (some can even be dimmed) than a conventional switch start ballast - so I wonder which they tested the myth with. I can't remember.

Interestingly though, for the average user, replacing an ordinary tungsten type lamp with a CFL or LED will produce savings but I have to be honest and state that I am a sceptic. Unless you have all tungsten type lamps in your house and leave them on half the day, switching to CFLs won't save you much money each month. Your big energy costs come from your electric shower, kettle, washing machine, tumble drier etc..

Only my opinion tho.....

matt_claydon - 29/9/08 at 04:21 PM

quote:
Originally posted by Mix
Hi

Is there any truth in the rumour that energy saving bulbs have to be left on for about twenty minutes before making any saving over normal filaments? The inference being they use quite a lot of energy in the start up phase.

Regards Mick

It's utter bull from an energy point of view and you can prove it very simply:

Lets say a fluorescent lamp takes 3 seconds of 'flicking' using a lot of electricity to start up.

A normal 100w bulb uses 0.02 kWh of electricity in 12 minutes.

To use 0.02 kWh in 3 seconds would require a power consumption of 24kW, a current draw of 100 Amps - I think not!

However, it may well be true that the life of the bulb is reduced significantly with every on/off cycle and so the bulb will die before it's paid for itself in low use situations.

greglogan - 30/9/08 at 01:38 PM

quote:

To use 0.02 kWh in 3 seconds would require a power consumption of 24kW, a current draw of 100 Amps - I think not!

Think on the savings you would make having to heat the room, tho

The cable would be like a heating element bouncing 100A thru it!

smart51 - 30/9/08 at 02:16 PM

quote:
Originally posted by greglogan
replacing an ordinary tungsten type lamp with a CFL or LED will produce savings but I have to be honest and state that I am a sceptic. Unless you have all tungsten type lamps in your house and leave them on half the day, switching to CFLs won't save you much money each month.

lets say you have your light on for 0.5 hours per day in the summer and 5 hours per day in the winter. Your light will be on for about 1000 hours per year

A 100W incandescent bulb will use 100 kWhrs of electricity or about Ł10 per year.

An 11W CFL will use 11 kWhrs of electricity or about Ł1.10 per year. An average saving of 75p per month. Not a lot but enough to pay for your CFL bulb in under a year.

That extra 89W is quite a lot though. 20 million houses using that is the same as a 200 MW power station running 24 hours a day 365 days a year.

MikeR - 3/10/08 at 11:58 AM

But .... twist this around.

What is the environmental cost of producing and destroying the energy saving bulb???

Its FAR higher than a normal bulb & i've yet to see a study that takes into account the fact a normal bulb gives off far more heat - therefore reducing your need to heat the room. In fact in my downstairs toilet, it doesn't have a heater but if you put the light on, after a minute its warmed it up enough for you to notice.

Also, if you break a energy saving bulb, immediately evacuate the room. You've just released mercury into the atmosphere. Come back in 15 minutes, open the windows and leave again for a while. Hopefully the mercury will then have been dispersed more finely into the atmosphere so its not noticable.

Having said all that, i'm replacing normal bulbs with energy saving ones as the normal ones blow.