On Wed, 31 Jan 2007 22:38:18 UTC, "Mary Fisher"
wrote:

"Derek Geldard" wrote in message
...
On Wed, 17 Jan 2007 12:15:38 +0000, David Hansen
wrote:

On Sun, 14 Jan 2007 13:52:41 +0000 someone who may be David Hansen
wrote this:-

I have been using such lamps in places like toilets for a decade,
without any problems. I have just decided to use them on the stairs,
as they now start quickly enough and reach enough output quickly
enough to be used there.

99p each from John Lewis for the bulbs I have used on the stairs. I
haven't stumbled in the sort of darkness the anti-CFL lobby claimed
I would experience for five minutes before they put out any useful
light.

Earlier in this thread I promised to make some measurements comparing
a 60w GLS filament lamp with a claimed to be 60w equivalent CFL. So I
dutifully bought a 60w pearl GLS lamp from Tesco (16p) and set up an
experiment with a luxmeter (taped so as not to move) on the outside of
the lampshade.

The GLS lamp reached 330 Lux at 5 sec. and maxed out at 350 Lux within
10 seconds.

The (brand new) 13 watt CFL reached 140 lux at 5 sec. and reached 240
Lux at 2 mins more/less maxed out.

A (1 year old) 13 watt CFL reached 80 Lux at 5 sec. and reached 124
Lux at 2 minutes more/less maxed out.

So after 1 year of use my feit electric 13 watt CFL gave out less than
25% of the light of a 60 watt GLS filament lamp within a reasonable
few seconds of waiting, and never got above 35%.

Comparing the brand new and 1 year old CFL's, it appears the light
output is down 48% in 12 months.

Q.E.D.

Not so. The light output from CFLs might not be as high as the GLS (I don't
believe that they are) but they give out enough light to prevent us oldies
stumbling, which is what David was saying.

Presumably that's what the manufacturers mean by 'equivalent' then...not
equivelent in light output, just 'bright enough'.

More marketing greenwash.

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