LED bulbs and electric savings

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Hard to beat LEDs just make sure you understand the color ratings. Cree makes a soft white that is close to incandescent but they also make some bright white ones that are very harsh. Great for lots of light but not so great to live with.


I installed CREE 45 watt / 12 volt spot lights on one of my farm tractors. Amazing is the difference between the stock Halogen and the LED's Price of admission is high but light output and reflective distance is fantastic.
 
Are any of the LED lights made in the USA???
Actually, Home Depot's 120V Cree LED 40W equivalent and 60W equivalent bulbs are labeled "Assembled in USA" on the packaging. That's another reason I was willing to give them another shot after the original test unit I bought died and was replaced by Cree.
 
On color ratings, I run 6500 Kelvin tubes in my shop for industrial lighting but 6000 and above is harsh lighting for in home use, way too white-bright. I believe 3500 Kelvin is mre like what you want for interior lighting.

I have no idea who 'Kelvin' is....lol
 
this guy...

Lord-Kelvin_1824-1907_-350x380.JPG
 
2700-3000 kelvin is what incandescent is supposed to be and also what is typically "soft white". The crees available are either yellow or blue, only the two choices. I always buy yellow which is aka soft white.

I like a nice 4000k tube in the shop, but no bluer than that. Remember that color temperature is not the same as lumens so the blue lights are no brighter but just a different color.
 
The fun thing is when you have daylight coming in at the same time....it is around 6000K
 
2700-3000 kelvin is what incandescent is supposed to be and also what is typically "soft white". The crees available are either yellow or blue, only the two choices. I always buy yellow which is aka soft white.

I like a nice 4000k tube in the shop, but no bluer than that. Remember that color temperature is not the same as lumens so the blue lights are no brighter but just a different color.

We do close tolerance high precision machining and exotic alloy fabrication (I own the shop btw, it's not a home shop). The 6-65K lighting contrasts incremental units on measuring tools very well and we need a large amount of light to see small details anyway. We run T5 and T8 tubes, T5 in high bay polished fixtures. and T8's in diffused fixtures,
 
I gave in and bought my first LED bulb. A 60W equivalent Polaroid 3000K for $4 at Menards. I wanted a LED for my outside front door since the CFL struggled on nights like tonight when it's below zero. The new bulb was bright right from the start. That's nice!
 
LEDs are cold loving critters. They actually get more "efficient" as the temps drop.
It seems so, I was up at 4:00 am tending to the stove and the outside temperature was -15 F. I open the door and flipped the light switch on and it sure seemed to be at full brightness. At that temperature the CFL that I had out there would not have warmed up enough to be bright even after some time. On the other hand the CFLs that are on the front of my shed are 15W floods encased in there enclosure and they do warm up after a few minutes in the winter.
 
HD had a sale on Philips 10.5w ( 60 w ) 800 lumen bulbs for $1.75 each so I bought a case . I like the instant brightness ( especially for the outside motion lights ) & being dimmable . There is a warning on the package that the LED bulb is not suitable for fully enclosed fixtures ........
 
I wonder how 3 or 4 LED 10.5w( 60w) bulbs would compare to a T12 75w fluorescent tube for light output ?
 
I wonder how 3 or 4 LED 10.5w( 60w) bulbs would compare to a T12 75w fluorescent tube for light output ?

Looks like the long tubes are about 60 lumens/watt: http://en.wikipedia.org/wiki/Luminous_efficacy
so maybe 4000 lumens total.

The best CFLs are at the same level of efficiency, and the best current LED bulbs are maybe 50% higher (90 lum/W in warm white).

To answer the question....get the lumen spec on the LEDs.
 
Thanks Woodgeek . The LED bulbs that I have are 800 lumens so it looks like I would need to have 5 of these bulbs to replace the light output of one T12 75w but they would only draw about 52.5 watts compared to the 75w T12 tube . Do I have that right ?
 
Now that I did the math , 60 lumens per watt would equal 4500 lumens for the T12 75 watt tube ....... That means I would need 5 or 6 LED bulbs to replace the T12 tube . 63 watts for 6 LED bulbs , still a slight savings .............
 
Not clear what the eff of the ballast on the T12s is, or if they are older they may be well below their initial brightness.

Subjective effects are hard to predict....for task lighting, the LEDs would prob be more concentrated, for shop lighting, it will just be about lumens. I like Warm White better lumen for lumen.
 
I wonder how 3 or 4 LED 10.5w( 60w) bulbs would compare to a T12 75w fluorescent tube for light output ?
I've debated this for some time with respect to a 24"x24" T12 40W U-bend fixture I have in my kitchen which spends quite a lot of time ON.

According to the manufacturer: The 40-Watt linear fluorescent U-Bent light bulbs feature a light output of 1950 lumens and last up to 18,000 life hours @ ~$10 each.

If I installed five 800 lumen LED (60W equivalent) bulbs in my 24"x24" fixture, I'd get 4000 lumens at around 50W. A replacement ballast for my T12 fixture is ~$20, so Edison sockets and LED bulbs start looking like an enticing upgrade if the ballast fails.
 
I'm pretty sure a flourescent fixture uses more juice than the sum of the bulb wattage. That's what I found when initially using my Effergy - but I forget now how much extra. I was chalking it up to the ballast using it. I ended up replacing two dual bulb 48" fixtures in my office, that were on usually 12 hours a day, with two ordinary dual socket fixtures with LEDs in them.
 
I replaced all the bulbs in the house with 2700k leds. I doubt I'm saving much compared with cfls, but they're performing well and are dimmable.
 
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