31 Days till OSH

The reason that there aren't white LED lamps is the same reason that
there aren't battery-electric airplanes. Right now, for "white"
light, fluorescent lamps are just about the most efficient thing
around. To make money, LEDs have to beat fluorescents and they aren't
quite there yet - but probably will get there within the next few years.



Matt Roberds

Matt,

Actually, that's not quite true. LEDs have just hit efficiencies of
90 lumens per watt, which is comparable to compact fluorescent. The
biggest barrier to LED light bulbs right now is cost, but that should
also change soon.

Dean

wrote:
wrote:
The reason that there aren't white LED lamps is the same reason that
there aren't battery-electric airplanes. Right now, for "white"
light, fluorescent lamps are just about the most efficient thing
around. To make money, LEDs have to beat fluorescents and they aren't
quite there yet - but probably will get there within the next few years.

Actually, that's not quite true. LEDs have just hit efficiencies of
90 lumens per watt, which is comparable to compact fluorescent.

In a lab, with a junction temperature of 25 C (in other words, on a heat
sink with Freon running through it.) 90 lm/W in an LED lamp that
your grandmother can buy and install in her kitchen is still a ways off.
I have no doubt it's coming but it's not here yet.

Matt Roberds

wrote:
The reason that there aren't white LED lamps is the same reason that
there aren't battery-electric airplanes. Right now, for "white"
light, fluorescent lamps are just about the most efficient thing
around. To make money, LEDs have to beat fluorescents and they aren't
quite there yet - but probably will get there within the next few years.

Actually, that's not quite true. LEDs have just hit efficiencies of
90 lumens per watt, which is comparable to compact fluorescent.

According to Klipstein (probably the most knowledgeable person on the
subject of lighting that I know) CFLs are still down at around 55-60 lm/w.
Only 32FT8 fluorescents are up in the 90+ lm/w range. (See upcoming
November KP article or the Monday Oshkosh forum.)

The below by Matt is also true. Lab conditions and home workshops are not
in the same league.

Jim


In a lab, with a junction temperature of 25 C (in other words, on a heat
sink with Freon running through it.) 90 lm/W in an LED lamp that
your grandmother can buy and install in her kitchen is still a ways off.
I have no doubt it's coming but it's not here yet.

Matt Roberds

On Jun 25, 12:50 pm, wrote:
wrote:
wrote:
The reason that there aren't white LED lamps is the same reason that
there aren't battery-electric airplanes. Right now, for "white"
light, fluorescent lamps are just about the most efficient thing
around. To make money, LEDs have to beat fluorescents and they aren't
quite there yet - but probably will get there within the next few years.

Actually, that's not quite true. LEDs have just hit efficiencies of
90 lumens per watt, which is comparable to compact fluorescent.

In a lab, with a junction temperature of 25 C (in other words, on a heat
sink with Freon running through it.) 90 lm/W in an LED lamp that
your grandmother can buy and install in her kitchen is still a ways off.
I have no doubt it's coming but it's not here yet.

Matt Roberds

If you say so...