Position of the filament in incandescent lamps makes a big difference.

[Peter Constantinidis]

I was experimenting with a couple incandescent lamps, when I noticed a GE
60 watt bulb was the same brightness and color seemingly, as the 60 watt
Philips halogena one i was experimenting with which was a lot more
expensive. I also had Philips regular incandescent bulbs and a few others
but they didn't have the same 'pop'.

I held both bulbs up to the light (heh heh) and I saw that in the Philips
one, the filament is horizontal. But in GE bulbs, the filament is vertical,
and longer than the horizontal Philips one.

So I think based on that bit of empirical evidence, that a vertical
filament provides more surface area to throw off light with and may also be
burning hotter due to the whiter color, the GE bulbs are better as when new
they look pretty much the same as Halogena bulbs for a lot less $.

Regards,
P.

 

[AC/DCdude17]

X-No-Archive: Yes

I was experimenting with a couple incandescent lamps, when I noticed a GE
60 watt bulb was the same brightness and color seemingly, as the 60 watt
Philips halogena one i was experimenting with which was a lot more
expensive. I also had Philips regular incandescent bulbs and a few others
but they didn't have the same 'pop'.

The cheapest type is usually the brightest. Sylvania and GE 60W lamps performs
the same. These cheap bulbs burn a lot hotter than 130V, long life,
decorative, etc etc.

I held both bulbs up to the light (heh heh) and I saw that in the Philips
one, the filament is horizontal. But in GE bulbs, the filament is vertical,
and longer than the horizontal Philips one.

So I think based on that bit of empirical evidence, that a vertical
filament provides more surface area to throw off light with

No. More surface area or length is bad. It provides more area for thermal
dissipation which in turn lowers efficacy. Filament orientation has nothing to
do with it. Lack of center support increases efficacy due to a slightly
reduction in conduction loss through support.

and may also be
burning hotter due to the whiter color,

You got that backward. It's whiter, because the filament is hotter. It is
just as efficient as halogen because filament burns hotter.

the GE bulbs are better as when new
they look pretty much the same as Halogena bulbs for a lot less $.

The difference is life.

60 and 100W halogena lamps are both 3,000 hours rated and they're just as
efficient as the cheapest regular incandescent equivalent.

60W incandescent is rated at 1,000 hours, 100W at 750 hours. There are some
with 2,000 or 3,000 hours ratings, but they suffer in efficacy.

Halogena line is most appropriate for where replacement is difficult or
expensive, but would still like to get an efficacy comparable to cheapest
incandescent.

 

[Victor Roberts]

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The cheapest type is usually the brightest.

Well, I guess there is no need for anyone to measure lamps any more as
you have discovered the "golden rule" Do you have any data to
support this statement, which is certainly not correct.

Sylvania and GE 60W lamps performs
the same.

Consumer reports did compare the performance of incandescent lamps
some years back. It might make interesting reading for you and others.
My perhaps incorrect recollection of the data was that lamps from the
big three were rather similar.

These cheap bulbs burn a lot hotter than 130V, long life,
decorative, etc etc.

Well, there is good data that lamps designed for 120 volts operate at
higher filament temperature than lamps of the same rated power and
life designed for 130 volts, but operated at 120 volts. But, you can
not say that ALL 120 volt lamps operate at higher filament temperature
than ALL 130 volt lamps (when they are operated at 120 volts.)

No. More surface area or length is bad.

Bad, as in "evil"?

It provides more area for thermal
dissipation which in turn lowers efficacy. Filament orientation has nothing to
do with it. Lack of center support increases efficacy due to a slightly
reduction in conduction loss through support.


You got that backward. It's whiter, because the filament is hotter. It is
just as efficient as halogen because filament burns hotter.

It is probably just as efficient as the halogen because it is
operating at the SAME temperature. However, the filament wire
temperature and the winding configuration also have an impact on the
efficacy for a given tungsten temperature and we don't know how these
compare between the two lamps.

Halogen fill does not make lamps more efficient at the same
temperature. It does reduce tungsten evaporation and thus increase
life compared to a non-halogen lamp of the same temperature and
filament construction.

 

[AC/DCdude17]

X-No-Archive: Yes

Well, I guess there is no need for anyone to measure lamps any more as
you have discovered the "golden rule" Do you have any data to
support this statement, which is certainly not correct.

I'm not saying there is no need to measure. I'm saying generally, the cheapest A19
usually gives the best performance compared to the same wattage general purpose
lamps.

Sylvania 120V 60W A19 870 lumens
Sylvania 120V 100W A19 1710 lumens

These are both 25cents each.

When you shell out more buck for long life, 130V, etc etc. you get less output.

I'd say these are the cheapest as you most likely won't find anything that is less
than a quarter each in a four pack.

Can you name a few same voltage, same wattage, soft white/frost lamps that exceeds
these lamps 3% or more in output?

I find that for most practical matter, picking the cheapest 120V bulb(no long life
gimmick) gives you the highest output.

Consumer reports did compare the performance of incandescent lamps
some years back. It might make interesting reading for you and others.

I have compared the specs for 120V, A19 frosted(the most common) from the big
three. They're all within a percent or two of each other.

Well, there is good data that lamps designed for 120 volts operate at
higher filament temperature than lamps of the same rated power and
life designed for 130 volts, but operated at 120 volts. But, you can
not say that ALL 120 volt lamps operate at higher filament temperature
than ALL 130 volt lamps (when they are operated at 120 volts.)

Never did I mention ALL 120V lamps operates at higher temp than ALL 130V lamps at
120V. The keyword is _cheap_ which basically limits to the most common type.

 

[TKM]

I was experimenting with a couple incandescent lamps, when I noticed a GE
60 watt bulb was the same brightness and color seemingly, as the 60 watt
Philips halogena one i was experimenting with which was a lot more
expensive. I also had Philips regular incandescent bulbs and a few others
but they didn't have the same 'pop'.

I held both bulbs up to the light (heh heh) and I saw that in the Philips
one, the filament is horizontal. But in GE bulbs, the filament is vertical,
and longer than the horizontal Philips one.

So I think based on that bit of empirical evidence, that a vertical
filament provides more surface area to throw off light with and may also be
burning hotter due to the whiter color, the GE bulbs are better as when new
they look pretty much the same as Halogena bulbs for a lot less $.

Regards,
P.

The vertical filament in the GE lamp was once promoted as the "Bonus Line"
design. I don't recall the magnitude of improvement - probably a
lumen/watt at the most. There were several "optimization" factors
involved: Assuming that the lamp is operated vertically, the filament
operates a little more efficiently because the heat from the bottom of the
filament helps keep the upper part hot. I think there was one less filament
support (did you count them, Peter) to minimize conducted heat loss. There
was also some benefit to the gas flow from the verticle filament, but I
don't remember how that worked.

Terry McGowan