Compact Flourescent Lights

[garsh]

When I collect enough bad ones, I take them back to Costco and they replace them with new ones for free.

Smart guy: never thought a retailer would do that.

Costco's return policy is hard to beat. Return anything at anytime for replacement or a full refund (except for some electronics like computers & TVs, which must be returned within 90 days).

 

[Nubo]

Just an off handed comment. What I have not understood about the LEDs is the HUGE heatsink required. I mean, come on, they are supposed to be so energy efficient, saving you money. Then why would they emit so much heat as to cause the above (nearly catastrophic) problem ? Ok, I've been told the heatsink is there to keep the LED cool because they don't like heat and last longer that way. Hmmm. Ok. But causing smoldering and just about a fire when enclosed ??!!! What's up with that. Not knowing the details, I'll still assume that the smoldering LED was a fraction in wattage of what the incandescent bulb used to be. Would the (higher rated) incandescent have caused that fire ? My guess is no.

Yes, it's to keep the LED cool and its associated electronics. Semiconductor electronics can't take anywhere near the heat of an incandescent bulb (a.k.a. "Gas and Glass"). Even though the LED produces far less heat per lumen, the heat is concentrated in a very small area and needs to be drawn away quickly otherwise the LED will suffer efficiency loss and short life.

You can draw an analogy to the LEAF. Even though the electric drive system does not produce anywhere near the heat storm of a gasoline engine, it does produce a small amount of heat and that heat needs to be quickly and effectively removed from the small concentrated area of the power electronics, whose semiconductor electronics can't take anywhere near the amount of heat as an engine block, oil, bearings, etc...

It doesn't take very many watts to make something small really hot if the heat is not dissipated. I have a small LED flashlight that runs on a single AA battery. If I run it at its maximum power (about 200 lumens @ 2 watts) it is fine if I'm holding it -- my hand acts as a heatsink. If I place the light on a table at that power and pick it up after 10 minutes of operation, it is painfully hot! Not a lot of heat, but it's concentrated in a small mass so the temperature gets high.

 

[DaveEV]

Just be careful.
I didn't research/read about LED's enough and put one in an enclosed globe in the hall. When the kids left it on all night the heat couldn't dissipate and it started to smolder.

Not good! This sounds like a design defect to me - a light bulb should never let the magic smoke out - never mind start a fire! What kind of LED bulb was this?

I had a 23W Feit CFL let the smoke out the other day. It had started flickering a bit when I turned it on, but that went away after it warmed up. 10 minutes later it flickered again, made a popping sound and let the magic smoke out. Did not catch on fire, though! Don't recall how old this bulb was, but no more than 4 years. Does typically get 2-4 hours of use a day.

 

[Deleted member 770]

There's one other technology that will (hopefully) be coming to market soon - Electron-Stimulated Luminescence, or ESL. From what I understand, think of a CRT that only produces light, not a picture. VU1 is currently the only manufacturer, and their first product will be a 65w floodlight replacement which will retail for about $15.00 USD. But it looks like a good alternative to incandescent, CFL and LED. They were hoping to have a product out in the first half of 2012, but they had to switch their manufacturing from Europe to China, so it's taken longer than they anticipated.

Personally, I've been burned by too many CFLs that either didn't meet their luminosity claims or got dim within a few months. I haven't waded into the LED waters yet, mostly due to the heat issues mentioned and high initial cost.

Disclaimer - I have no interest in the company other than as an impatient end user.

 

[ksnogas2112]

I forget the actual brand of LED. It was one of the cheaper ones and the bulb itself stayed sealed but the heat sink and it's surrounding plastic melted and caught fire. Still haven't replaced the fixture so it's dark in the basement hall.

Re: CFL, the Home Depot's around here accept them for recycling.

 

[Deleted member 3147]

Hello,

How do these manufacturers know that there LEDs will last 20 years??

Do the energy savings warrant the higher cost?

Saleem

LED's have been around since the 1950s - they've got a very good track record.

However, the "white" LEDs are fairly new. They do have limited life, not due to the LED itself, but due to the phosphors used to turn the blue LED light into white light.

This is one reason that the Philips bulbs are so good. They remove the phosphors from the LEDs and put them in the yellow plastic shell. This keeps it cooler for a much longer life.

The other limited life element, as others have mentioned, is the electronics to drive the low-voltage LEDs from 120V.

 

[Ingineer]

90% of the CFL's I have performed a failure analysis on when they failed early were due to Electrolytic Capacitor failure.

I noticed some the the good LED brands (Phillips) are not using Electrolytic caps in the power supply design, which may greatly help reliability.

This is also likely what lets the "magic smoke" out when overheated too much.

-Phil

 

[cwerdna]

When I collect enough bad ones, I take them back to Costco and they replace them with new ones for free.

Smart guy: never thought a retailer would do that.

Costco's return policy is hard to beat. Return anything at anytime for replacement or a full refund (except for some electronics like computers & TVs, which must be returned within 90 days).

I think it's YMMV. I had one in a box of 10 FEIT CFLs from Costco die very early, in less than a year, despite the 10K hour supposed life rating on the box (and I wasn't running them 24/7). They wouldn't give me a replacement for the bad bulb I brought in. At the time, I had the receipt.

I haven't tried against since and I've moved, so I'd be going to a different Costco. Not sure if the ones near me now would be more willing.

 

[garsh]

I had one in a box of 10 FEIT CFLs from Costco die very early... They wouldn't give me a replacement for the bad bulb I brought in.

They told me that there was some minimum percentage that had to die before they would replace them. I think it might have been 50%. Just hang onto the dead ones until you have closer to a full pack, then try again.

 

[cwerdna]

I had one in a box of 10 FEIT CFLs from Costco die very early... They wouldn't give me a replacement for the bad bulb I brought in.

They told me that there was some minimum percentage that had to die before they would replace them. I think it might have been 50%. Just hang onto the dead ones until you have closer to a full pack, then try again.

Crap. I think I already disposed of some and I don't know if I can find my receipt now (I think the CFLs were <$1.20/piece).

The local hardware store accepts CFLs, fluorescent tubes, and batteries for recycling.

 

[smkettner]

49 cents enclosed, 10 cents spiral

http://www.ganahllumber.com/wp-content/uploads/2011/06/100023-proj_ad_7_web.pdf

What is the payback on that.... a day?

 

[cwerdna]

49 cents enclosed, 10 cents spiral

http://www.ganahllumber.com/wp-content/uploads/2011/06/100023-proj_ad_7_web.pdf

What is the payback on that.... a day?

Wow. That's cheap. Too bad they have no such stores up here in Nor Cal.

Is that sale or are they regularly that cheap? If the latter, perhaps I'll pick some up the next time I'm down there.

 

[smkettner]

Periodic local promotion. I picked up 10 for a buck early this year as spares and I recently saw the flyer in the newspaper this week again.

 

[richard]

I had one in a box of 10 FEIT CFLs from Costco die very early... They wouldn't give me a replacement for the bad bulb I brought in.

They told me that there was some minimum percentage that had to die before they would replace them. I think it might have been 50%. Just hang onto the dead ones until you have closer to a full pack, then try again.

Crap. I think I already disposed of some and I don't know if I can find my receipt now (I think the CFLs were <$1.20/piece).

The local hardware store accepts CFLs, fluorescent tubes, and batteries for recycling.

I just ran into this last weekend at Home Depot. Tried to return one bad bulb from a 2-pack. Would have accepted almost anything, but I think the obvious thing is to offer a half-refund.

The return lady said they could only return a full pack. So yes, as idiotic as it sounds, I have to return a good bulb with the bad one to get a refund/credit. Very wasteful.

 

[AndyH]

Hello,

How do these manufacturers know that there LEDs will last 20 years??

Do the energy savings warrant the higher cost?

Saleem

Saleem, LEDs have been around since the 1950s (Bell labs, I think). The transister is from roughly the same vintage. An AC LED lamp has electronics inside to convert the 120V AC to the direct current the LEDs need. The LED's themselves will last a very long time. The electronics in a quality lamp should also.

Bottom line - there's not much 'new tech' in LED lamps - it's just that the price to build the device is finally come down enough. All the bits inside have very long track records.

edit...gack - I see Doxy and Ingineer already covered this. Sorry.

Do the energy savings warrant the higher cost?

Yes. Start replacing the most used lamps in the house. You might not replace the lamps in closets until they burn out because they're not used enough to show an energy savings. But replacing the rest will save money. Here's an example from my office:

I have a ceiling fan that holds four bulbs. I used four 60W incandescents initially. The lights are used about 13 hours per day 7 days a week. My electricity is about $0.135 per kWh.

Incandescent: 4x60W=240Wx13 hours= 3120 Wh or 3.12 kWh per day x 365 = 1138.8 kWh per year x $0.135 = $153.74 per year

LED (Philips L-prize 60W equiv.): 4x10W=40Wx13 hours= 520 Wh or 0.520 kWh per day x 365 = 189.8 kWh per year x $0.135 = $25.62 per year

LED savings annually: 153.74-25.62 = $128.12
Cost of bulbs: $35 each x 4= $140
If electricity prices stay the same, the lamps will pay for themselves in 13 months.

 

[mendenmh]

Saleem, LEDs have been around since the 1950s (Bell labs, I think). The transister is from roughly the same vintage. An AC LED lamp has electronics inside to convert the 120V AC to the direct current the LEDs need. The LED's themselves will last a very long time. The electronics in a quality lamp should also.

The LED lamps being sold now do have one major bit of new technology. For a long time, most LEDs were Gallium Arsenide (GaAs) or Gallium Aluminum Arsenide (GaAlAs), which is a long-wavelength (red/infrared, depending on how much aluminum) emitter. The stability of these is well understood. For along time, there was a problem with aluminum migration causing dark spots and, eventually, failure. That problem has been mostly resolved.

Now, most of the LED lamps are Gallium Nitride (GaN) lamps, which emit in the deep blue and near ultraviolet. They have a phosphor coating to convert this to a white color to make a useful light. In many senses, they are a lot like fluorescent bulbs, which take the very strong ultraviolet emission from mercury vapor and convert it via a phosphor to visible light. Because of the high power density at which these LEDs are operated, they get quite hot locally. With a good heat sink, they can last a very long time. However, good heat sinks cost money, and not all manufacturers are spending it. Therefore, there is a wide range of lifetimes in LED lamps. GaN can operate at a fairly high temperature, but it has it limits.

Nonetheless, I entirely agree that these are a really good idea. The energy savings are huge, and they don't contain mercury. I unfortunately bought a large stock of CFLs by accident (forgot I had already bought them, bought more...) so it may be a long time before I buy any new lights.

 

[AndyH]

...Now, most of the LED lamps are Gallium Nitride (GaN) lamps, which emit in the deep blue and near ultraviolet. They have a phosphor coating to convert this to a white color to make a useful light. In many senses, they are a lot like fluorescent bulbs, which take the very strong ultraviolet emission from mercury vapor and convert it via a phosphor to visible light...

Very cool - thanks for this! I'm too young to be stuck in the 1960s! :lol: