LED replacement bulbs

[Bobbyb]

Kirk's LED shop lights are no more efficient than a T8  4 ft. flourescent. I am surprised as usually the LED is far  more efficient.

[docj]

1 hour ago, Bobbyb said:

Kirk's LED shop lights are no more efficient than a T8  4 ft. flourescent. I am surprised as usually the LED is far  more efficient.

Yes, the energy use is the same but the LED one produces 3200 lumens of light while a standard T8 tube has an initial output of ~2850 lumens.  So, the energy efficiency of the LED tube is higher and, unlike a fluorescent tube, the light output won't decrease with time.  Even though fluorescents are efficient, LEDs are more efficient.  That's one of the reason, among several, that LEDs have pretty much pushed compact fluorescent light off the shelves.  How much light is produce by a T8 tube?

Edited December 6, 2019 by docj

[sushidog]

LED efficiency is usually determined by the "generation" of LED, or the technology used in manufacture, and by the color temperature of the light produced. A LED that emits a warmer (lower kelvin) or yellower light has a lower efficiency than one emitting a bluer (higher kelvin) light.

Older generation LEDs typically produce about 45-55 lumens/watt depending on color temperature. My headlights use one of the newer high efficiency 4w Philips bulbs which produces 167 lumens/watt. Philips now produces LEDs which emit over 200 lumens/watt.  Yet I have some of the most efficient LED emitters I have seen in my reading light swivel sockets at 300 lumens/watt. They even have one on a meter in their ad proving the output for the sceptic. The maximum theoretical limit for a 100% efficient emitter is 680 lumens/watt, so there's still lots of room for improvement in LED development.

The most efficient fluorescents go up to around 65-70 lumens/watt, but these are industrial bulbs designed for warehouses with an uncomfortably high color temp and a very bluish tint operating off of high line voltage with less ballast heat loss. Your typical warmer, home use fluorescents make around 35-45 lumens/watt. For comparison a typical incandescent bulb only produces 9-13 lumens/watt, maxing out at 17 lumens/watt. Halogen bulbs (which are basically tungsten incandescent bulbs which use a low-pressure halogen gas to allow evaporated tungsten metal to be redeposited back onto the filament) emit up to 24 lumens/watt.

The advantage of a halogen (and a normal incandescent) bulb over fluorescent and LED lighting is it produces light with a perfect 100 CRI (Color Rendering Index). Tungsten incandescent lighting emits a full, continuous spectrum light that renders all colors exactly as sunlight does, which is one of the reasons it was used for so many years despite its relatively low efficiency. This gives it a niche market in the film industry and in certain scientific applications where perfect color rendition greatly outweighs its lack of efficiency - just not for general, everyday use.

Now you know more facts (not opinions or preferences) about various kinds of lighting than I'm sure you wanted to. 

Chip

Edited December 6, 2019 by sushidog

[rickeieio]

Just to add a little fuel to the fire.......

If one were to buy a LED unit and it lasts perhaps 10 years under intermittent use, you can expect the price of electric to go up in that time, extending the payback period.  But, you say, you don't buy electric, because you stay in an RV park where it's included, or boondock.  RV park owners WILL raise prices to recover that expense, and with solar you still want to reduce wattage consumption.

It's not as simple as it would seem.

[Barbaraok]

5 minutes ago, rickeieio said:

Just to add a little fuel to the fire.......

If one were to buy a LED unit and it lasts perhaps 10 years under intermittent use, you can expect the price of electric to go up in that time, extending the payback period.  But, you say, you don't buy electric, because you stay in an RV park where it's included, or boondock.  RV park owners WILL raise prices to recover that expense, and with solar you still want to reduce wattage consumption.

It's not as simple as it would seem.

No, you would reduce the payback period because if you are using more with incandescent, then that will cost even more over the 10 years.  

[rickeieio]

Duh, that's what I meant.

It's not as simple as it would seem......😉

[Barbaraok]

I understand - if I'm using my iPad I'm never sure what will be there when I hit send as that's when the 'auto check' seems to engage.  And it's idea of what I wanted to say and mine are miles and miles apart.😎

[noteven]

I think the most baffling North Am traffic control to drivers from “overseas”  is the 4 way or all way stop. 

We were guests in a home in England. Our host asked what I liked best about UK driving - I said besides how drivers “keep left” - keep right for right side countries- is the extreme lack of stop signs at junctions that are not roundabouts. We saw 1 in 1600 miles of touring. He looked at us and said, “Why would you stop if there is no one approaching the junction?”

[docj]

1 hour ago, noteven said:

“Why would you stop if there is no one approaching the junction?”

Down here in TX we have lots and lots of four-way stop intersections.  And woe is he who doesn't come to a complete stop regardless of whether or not there is any other traffic there.  We even have  local police who position themselves at busy 4-way stops just to enforce the "full stop" rule.

[Barbaraok]

2 hours ago, noteven said:

I think the most baffling North Am traffic control to drivers from “overseas”  is the 4 way or all way stop. 

We were guests in a home in England. Our host asked what I liked best about UK driving - I said besides how drivers “keep left” - keep right for right side countries- is the extreme lack of stop signs at junctions that are not roundabouts. We saw 1 in 1600 miles of touring. He looked at us and said, “Why would you stop if there is no one approaching the junction?”

Because it is the law.  You can not always see down the road coming the other way.  Again, it is the law.

[noteven]

He didn’t mean not stopping at a stop sign. He meant why force a stop with a sign at a clear visibility intersection. They use “give way” or yield signs where a busier road takes precedence over an intersecting road.  Their countries are not festooned with stop signs.
It’s pretty much a moot point in CanAm now as we have 2 or 3 generations who drive waiting for a sign to tell them what to do.
The latest is innovation is when they put a stop sign on what feels like a naturally “through road” because the lawyers sued the local council on behalf of someone who doesn’t know the rules of the road, the sign has a string of flashing red LED Christmas lights around it so you can see it from your house at 3:00 a.m.

There we are back on topic😀

[Ray,IN]

4 hours ago, noteven said:

 

There we are back on topic😀

Actually not, return to the original topic post and read the contents and thread title, which pertains to switching to LED lighting.Yea, I know nitpiking.🧐

Now if anyone wants to drive where stop signs are optional, drive into a town in Mexico.

Edited December 7, 2019 by Ray,IN