LED not that efficient.

[Stubby79]

Originally Posted by redpoint5

How does the utility penalize for low power factor? I thought the meter measures watts, and that's what you pay for?
.

AFAIK, it's only relevant to commercial/industrial usage.

[oil pan 4]

The digital meter I had at my last house had two additional readings that read "KWH 80% P.F." and KWH 60% P.F.", in the world of electrical generation and distribution there aren't very many things that could mean.
Then I have tested an old electro mechanical utility meter powering a 140w 500va 120v welder at no load versus light bulbs.
I found that a 200w light bulb didn't spin the meter nearly as fast as the welder. But the welder spun the meter as fast as a 500w halogen work light.
If the meter only counted watts then the 200w bulb should have spun the meter faster than the 140w 500va welder.
The only logical conclusion is that electromechanical and digital meters do read volt-amps.

As far as I can tell I am the only person to have ever actually tested this.

T5 high output is much better in the cold. I have fired mine up at about 12°F and they came right on, came up to full brightness in about 3 minutes.
But I'm also using enclosed commercial grade HO ballasts and German tubes in most of my fixtures.

My new place came with a pair of standard T5 fixtures with cheap Chinese ballasts and tubes, yeah i agree those are junk. So I know what you are talking about.
I may end up gutting them and putting in 120v T5 LED tubes in them.

[Stubby79]

Originally Posted by oil pan 4

.
Then I have tested an old electro mechanical utility meter powering a 140w 500va 120v welder at no load versus light bulbs.
I found that a 200w light bulb didn't spin the meter nearly as fast as the welder. But the welder spun the meter as fast as a 500w halogen work light.
If the meter only counted watts then the 200w bulb should have spun the meter faster than the 140w 500va welder.
The only logical conclusion is that electromechanical and digital meters do read volt-amps.

It may be that the RATED OUTPUT of your welder was 140w. It may be that it pissed away another X00 watts as waste heat in the transformer/circuitry, and had little to do with power factor. It may also be that just because 140w is it's RATED usage, it can and could put out a lot more for a brief period. Like a typical motor can put out 2 or 3x it's rated output for a limited period.

Or you could be spot on with your deduction. Rather hard to tell without further testing.

[oil pan 4]

140w 500va was what the kill-a-watt meter was showing.
Not ratings on the machine it's self.
That waste heat is physical manifestation of low power factor and excess volt amps.
Going by what the machine name plate says is a rookie mistake. The only things I have found that consistently near name plate is lights and heating elements.
Next?

[teoman]

Random info:

The max that an led can generate is ~680 lumens / W. For green light. In this case you would have 0 heat being generated.

[samwichse]

Originally Posted by oil pan 4

Where do I get these and how much are they?

https://www.amazon.com/100-watt-Dimm...electric+bulbs

Sadly, in the name of cheapness, all these multi-pack bulbs forgo the beefy heatsinks of their forbears and have half the rated lifetime.

[oil pan 4]

Something like my flood lights that are outside, only get used when it's cooler out at night and are on a timer the big heat sinks could be foregone.
But inside lights where they could be left on for 24hrs, kind of need the big heat sink.

[JSH]

Originally Posted by oil pan 4

Where do I get these and how much are they?

The CREE bulbs were purchased 4 years ago at Home Depot for about $8 each. That was when 5000K (Daylight) bulbs were hard to find so I splurged and purchased them for the living room. (The rest of the house got 3000K FEIT bulbs for about $2 each)

The FEIT bulbs were purchased at Costco this year for $2 each (after about a 66% credit from Energy Trust Oregon) They are about $7.50 at Home Depot. I replaced all my 3000K bulbs with 5000K and gave the old bulbs to a friend that was still using incandescents.

The older CREE have a beefy heat sink / the FEIT do not.

[ASV]

a lot of white light LED are actually ultra violet LED shining through a micro dot florescent medium.
The medium will burn away over time leaving more and more UV and less white light. the amount of light being generated stays the same.
You just can't see it.
I believe this is caused by the relatively high intensity of UV

[redpoint5]

Originally Posted by JSH

The CREE bulbs were purchased 4 years ago at Home Depot for about $8 each. That was when 5000K (Daylight) bulbs were hard to find so I splurged and purchased them for the living room. (The rest of the house got 3000K FEIT bulbs for about $2 each)

The FEIT bulbs were purchased at Costco this year for $2 each (after about a 66% credit from Energy Trust Oregon) They are about $7.50 at Home Depot. I replaced all my 3000K bulbs with 5000K and gave the old bulbs to a friend that was still using incandescents.

The older CREE have a beefy heat sink / the FEIT do not.

Wait, you said you replaced the 3000k FEIT bulbs with the 5000k Cree. The FEIT are the newer bulbs and the Cree older. But then you said you gave the old bulbs (Cree) to a friend, which would leave you with the newer 3000k FEIT.

Anyhow, the main thing missing is which are more energy efficient.

Originally Posted by ASV

a lot of white light LED are actually ultra violet LED shining through a micro dot florescent medium.
The medium will burn away over time leaving more and more UV and less white light. the amount of light being generated stays the same.
You just can't see it.
I believe this is caused by the relatively high intensity of UV

Is this still the most popular way to produce white light from an LED? The other method, and I believe is more efficient, is to combine RGB LEDs into a single package that gives the illusion of white light.