low energy bulbs again - how low energy?

[The Medway Handyman]

Assuming that low energy bulbs are more efficient & give off less heat for a given amount of light, would you not have to replace that heat in order to maintain the same room temperature?

[The Natural Philosopher]

They have done them, but they aren't telling you the results.

Because they are laughable.

[Peter Parry]

Sort of, but as you dim them the colour rendering, which isn't particularly good to begin with, gets badly skewed and the resulting output tends to be shifted towards the blue end of the spectrum creating exactly the opposite effect to the one you want.

[Peter Parry]

Its not corruption but bribery - which the EU doesn't regard as corrupt because France and Italy for a start rely upon it to get their way. Osram, Philips and GE have been the major proponents of this legislation (Osram in particular who apparently wrote the first draft) and have developed a halogen equivalent of the incandescent bulb which fits in the new legislation (what a surprise) saves about

10% on electricity in its production form and sells for 10 times the cost. Most importantly it is patent protected in the EU which allows inefficient EU manufacturers to keep out nasty foreign competition.

[Roger Mills]

I already have!

[Roger Mills]

So is there one that will give as much light as a 150 watt tungsten bulb?

No, I thought as much!

[Andrew Gabriel]

They would be completely wrong for that. Actually, the high colour temperature "daylight" tubes are completely wrong for almost every application you can think of.

[Roger Mills]

Tom Harrigan has kindly supplied that by the bucketful - saving me looking up the references.

No of course not. But if I can't replace tungsten with low energy on a one for one basis, I'll have to install a lot more lighting points which - quite apart from any cost and Part-P inplications - will spoil the look of many of my rooms.

Some rooms have low voltage halogen downlighters. What am I supposed to replace *those* with?

[Roger Mills]

Ah, I stand corrected. I see that there *is* a 60w jobby which claims to be the equivalent of 300w - so will probably match 150w in reality.

But at nearly 50 quid a throw - forget it!

[Bob Eager]

Same here.

[Bob Eager]

Try to buy them soon, and the Drug Squad will probably be knocking on your door. Then you'll be needing a licence to buy them, and ...

[Peter Parry]

The Warwickshire Wind Energy Project, urban sites on houses are generating negligible amounts of electricity, often less than that consumed by their control gear never mind their production/shipping energy cost. Typically in an urban environment you will generate electricity worth about £4 in one year.

The Barratt Chorley trial and St Albans Ecohome have produced similarly trivial levels of electricity, way below that which would pay back the energy of production, distribution and installation.

In all the locations above the sites were assessed as being suitable for wind generation before installation.

[OG]

Yes but If your room needs heating, use a heater and put it where the heat needs to be. It's madly inefficient to put a heater about 10 inches from the ceiling (which is in effect what you are doing with incandescent bulbs). It's not as though the 'heat' produced by the bulb is a minor part of the cost of running such a bulb; for every 50p spent on a powering a standard 100W bulb (probably the typical daily cost at this time of year), at least 37.5p goes into heating; but your 37.5p would be much more efficective if spent powering a 'proper' heater.

You pay 50p but only get 12.5p worth of light. You can do far better spending your 37.5p on powering a proper heater.

[OG]

I've not got any figures, but taking the worst case conditions

Costs will break down into 3 components Material costs (cost of raw materials) Assume = zero Assembly costs (cost of getting people to put them together) Assume = zero Energy costs (what you are asking about).

In China energy costs are about 1/3 of ours*, so given that UK retailers can sell at bulbs at £1 we can set an upper limit for the energy cost of 30KWh per bulb in China . We also assume that the manufacturer, importer and retailer are all selling the bulb at cost price.

If we compare 6000 hours of CFL useage at 25W with 6000 hours of GLS at

100W, we get an energy useage of 150 KWh for the CFL and 600KWh for the GLS

Assuming the very worst case (that the GLS bulb had absolutely no energy cost at all), we can see that there is still a 420KWh lifetime benefit per bulb. (70% reduction in electricity saving)

Cost of Electricity in China

[Bob Eager]

A 25W GLS actually produces as much light as 100W incandescent? I think not.

Disposal costs? Additional transport costs? (they're heavier). Just pointing out that the picture is bigger..

[Bob Eager]

Of course, I meant CFL!

[Si]

In message , Peter Parry writes

You presumably have measured this Peter. My human experience of dimming my 70W CFL is that the colour balance is reddish when first switched on, becomes more neutral as it warm up, and having got to temp' doesn't change as it's dimmed.

[Andrew Gabriel]

There's a 30W one, ES only, in Homebase. Using the 1:4 rule (and ignoring any equivalence on the packaging), that's equivalent to about 120W. These higher power CFL's generate enough heat to significantly shortent their life if operated base- up or in enclosed fittings.

Alternatively, make your own 162W compact fluorescent...

[Peter Parry]

No, it was from "Lighting" magazine which tested about a dozen different types and reported on it a month ago. I'll see if I still have the copy around.

[David Hansen]

On Wed, 09 Jan 2008 16:44:27 GMT someone who may be Mike Scott wrote this:-

The people who have studied these things in detail say so and I believe them. If you want to look at the figures try using a search engine to study them.