differing light output between Halogen bulbs

[The Night Tripper]

Hi All I recently fitted a pair of new light fittings - ceiling things with

3x G9 halogen bulbs in each fitting. Each bulb has an opal glass surround. The fittings were supplied with (frosted) 40W halogen G9 bulbs.

I'd guesstimated that the resultant brightness would be greater than that of the old fittings they replaced, but was a little disappointed with the result. However one of the bulbs as supplied was faulty, so I bought a replacement pack; 2x 40W clear G9 from B&Q (yes, I know, but it was a Friday night...).

The 'B&Q' bulb (mfd. by GE) was significantly brighter than those supplied, to the extent that I bought a couple more packs and replaced the lot. I'm now happy with the resultant brightness.

But I'm wondering; is the increased brightness because the GE bulbs are clear, and the originals were frosted, or is it because the originals are cheapo no-name ones made in China and with a possibly dubious wattage or efficiency? I'm interested to learn if there's such a difference...

Cheers j^n

[Dave Plowman (News)]

There's a big difference in car headlight bulbs of the same wattage by maker - so I'd guess it's down to design and manufacture.

[Andrew Gabriel]

There are a number of potential factors...

Halogens can be manufactured to be either more efficient than conventional filament lamps by burning very slightly hotter, or to have longer life. Nearly all the consumer grade halogens are manufactured to have longer life (with same efficiency as conventional filament lamps), because it turns out domestic consumers won't pay the extra for a halogen lamp if it only lasts same length of time as a conventional filament lamp -- they never consider efficiency at point of sale (well, anyone who does is unlikely to be buying a halogen in the first place).

The frosting does lose light.

Different manufacturer's are likely to vary. (I once had some very bad halogens sold under the Ring brand, which behaved as though they just had a vacuum in them.)

[meow2222]

Neither. The brighter bulbs will have shorter lives. Explained here:

[The Night Tripper]

Hi All Thanks for the comments. I can appreciate the trade-off between light output and efficiency; but the GE ones are rated at 2500 hours I think, putting them towards the longer-lasting end; I guess I was expecting the cheapo ones supplied not to be 'super long life'!

Anyway, interesting comments, thanks

J^n

[Adam Aglionby]

What would you suggest the informed consumer would buy instead?

Adam

[Adam Aglionby]

Short life high intensity halogen lamps are more usually found in things like projectors and aircraft landing lights, lifetimes of 25 hours or less are not uncommon.

In less specialised markets lifespan, MTBF, of 2 500 hours is common, these will be considerably more efficient than a non halogen incan and longer life lamps typically 4Khrs, lower colour temp typically, still a deal more efficient than non halogen incan.

Some low cost Asian lamps are OK, got to watch out for line voltage

230V lamps destined for euro market that really don`t like our mainly 240V + mains.

A lot are not very good at all, there are reasons why the big 3 lamp makers, stay the big 3, Philips, GE and Osram and its not all to do with sharp marketing.

Good quality branded lamps can be worth the extra, theres quite a lot of development has gone into that hot wire in a bottle.

With exposed halogen capsules in current vogue in multi lamp ceiling fittings , quality branded lamps are certainly worth the premium for output and safety .

As Mr Elmer Fridrich says halogen still is "the most beautiful light quality of anything on the market"

[meow2222]

ing things with

halogens typically last 1500 hrs to 4500 hrs, the latter are inevitably much dimmer. I doubt the OP would be putting 25 hr lamps into domestic light fittings - though who knows.

NT

[Dave Plowman (News)]

Indeed. And of course the lamps in the fittings themselves can look good to - unlike CFLs.

[The Natural Philosopher]

Definitely true.

Halogen spectrum is almost late afternoon in color temperature..and broad.

And they heat the house too!