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Discussion Starter · #1 ·
I was reading about the LED bulbs that replace the incandescent bulbs.

Example for this thread.

60-watt replacement LED bulbs typically only use around 10 watts.

If the bulb says 60-watt equivalent, that's for the measure of lumens, correct?

If I have a light fixture that says 60 watt max, how big of an LED bulb can I safely put in it? If I want a brighter bulb, can I put a 75W equivalent LED which actually only used around 14 watts? What about the 90W equivalent which still only uses less than 20 watts?

Is it true that LED bulbs produce less heat than an incandescent?
 

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The 60 watt equivalent LED is approximately equal in lumens to the old 60 watt incandescent. The match is not exact, and the color spectrum is different, so they may not look the same.

LEDS use about 1/5 as much electricity as traditional incandescents, and they put out a lot less heat. The actual bulb temperature is a bit difficult to measure, but see this article for a good discussion http://sewelldirect.com/articles/led-vs-incandescent-light-bulbs.aspx.

For any fixture that will take a 60 watt incandescent, you can put any size LED typically available in without any heat problems.
 

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A "Handy Husband"
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While LEDs generate much less heat than incandescent they do generate heat. And excessive heat will kill a LED. You need to be concerned about how the LED is oriented in the fixture: lamp pointed straight down is worst case as all the heat moves up to the driver circuit. Also of concern is a closed fixture that traps the heat.
 

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When a fixture says 60 watts max you use the actual wattage of the bulb not the fake 'equivalent' wattage.
As for brightness I find that most of the new bulbs also state a lumen value on the package.
 

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The fixture will not overheat because it's rating is based on actual wattage, not some sort of fake "equivalent" rating (see if you agree that it's actually as bright as a 60W incandescent). However, as rjniles says, the LED bulb itself is much more sensitive to heat than an old fashioned lightbulb because it contains delicate electronics. Even though the fixture won't get as hot with the LED in it, the LED itself may fail early from its own heat if it's in a closed-up fixture.
 

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mpoulton said:
The fixture will not overheat because it's rating is based on actual wattage, not some sort of fake "equivalent" rating (see if you agree that it's actually as bright as a 60W incandescent). However, as rjniles says, the LED bulb itself is much more sensitive to heat than an old fashioned lightbulb because it contains delicate electronics. Even though the fixture won't get as hot with the LED in it, the LED itself may fail early from its own heat if it's in a closed-up fixture.
Electronics reliability goes down with rise in temperature. This is why led bulbs have a built in heatsink to extract the heat from the electronics. In a tightly enclosed fixture you undo the effectiveness of the heat sink as the heat has no where to go. So it won't be a fire hazard or violation of the fixture rating but at $10-15/led bulb it could get expensive. Fixtures where there is some outside airflow are better, fixtures with the bulb open are best. If a sealed enclosure the larger the surface area of the cover the better but be prepared for the bulbs to not to meet their published life (and it won't be a warranty claim due to the application).

Also light switches for electronic bulbs are not to be used at the nominal led wattage rating added up for the branch. They must be derated because of turn on surge current of the electronics on the bulb input. So a say a 600W dimmer shouldn't be used on a branch with forty 60W led bulbs (which draw 15W nominally). I haven't seen clear guidelines of the derating so I'd refer to the bulb manufacturers suggestions.
 

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I use one in our front porch light. Two for the fixture that is for the Basement Stairwell. They give a lot of light, if have a large enough area to reflect. Otherwise items like bathroom fixtures. They appear very dim.
 

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1 - If the bulb says 60-watt equivalent, that's for the measure of lumens, correct?

2 - If I have a light fixture that says 60 watt max, how big of an LED bulb can I safely put in it?

3 - If I want a brighter bulb, can I put a 75W equivalent LED which actually only used around 14 watts? What about the 90W equivalent which still only uses less than 20 watts?

4 - Is it true that LED bulbs produce less heat than an incandescent?
1 - Yes !
2 - Almost any that will phyically fit in .
3 - Yes !
4 - Certainly ! A great deal less than an incandesant.

But they do produce some heat, and you must consider it, a well ventilated fixture will give good long lamp life, a sealed unventilated one will give short life.

The rating on a lamp fixture mainly refers to the heat generated by an incandesant lamp of that rating.
So the fixture will with stand the heat of an 75w incandesant lamp.

 

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You need to be concerned about how the LED is oriented in the fixture: lamp pointed straight down is worst case as all the heat moves up to the driver circuit. Also of concern is a closed fixture that traps the heat.
I'm not so sure that's true. While LED's do produce heat, most of the heat is out of the back side of the led. The driver circuit also produces heat. If you flip the bulb up one way you're driving heat from the LED's into the driver circuit. If you flip it the other way your driving heat from the driver circuit into the led's.

Total guess here but logically speaking a LED bulb will be MORE stable when pointed right down. The led's (more sensitive to heat than the driver circuit ) will stay cooler.
 

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Discussion Starter · #10 ·
I use one in our front porch light. Two for the fixture that is for the Basement Stairwell. They give a lot of light, if have a large enough area to reflect. Otherwise items like bathroom fixtures. They appear very dim.
I'm currently using the "60W equivalents" on both porch lights, the kitchen, and a hall way. All of them are brighter than the 60W incandescent that I had in there before. All fixtures except the hall way are either open on top, or have a way to vent heat out of the top. The hall way is completely closed in, and it still puts out more light than the previous incandescent. The hall way light never stays on for more than a few minutes at a time though.
 

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I like the look of LED. I'm running PAR 20 'cool white' in my ceiling pots in the basement and it doesn't feel like a basement anymore. The lighting makes it look like a main level now and more of a household extension as opposed to just another finished basement.

It wasn't cheap though. 12 bulbs at $25 each plus the dimmers....
 

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A "Handy Husband"
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The price of LEDs is dropping fast. I saw a 2 pack of 60 watt equivalent dimmable, Lowes house brand for $8 and change.
 

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The price of LEDs is dropping fast. I saw a 2 pack of 60 watt equivalent dimmable, Lowes house brand for $8 and change.
Actually LED's don't have to be anywhere near as expensive as they are now. They cost pennies to make. It's all the driver curcuitry that has to be used to make it compatible with our older style of electricity and delivery system

If LED lighting ever becomes standardized then you could run a single central power supply, perhaps one on each floor and they would in turn supply all the power for all the led's on that floor. Bulbs would be MUCH cheaper because they would no longer need the drivers. They would run cooler, and with proper regulated DC power supplies, dimming would be cheaper and smoother and changing a bulb would take place maybe once every 8 or 10 years. Dimming a standard LED bulb with our present method of electrical supply and current type is a bit of a messy business when it doesn't really have to be.

Anyways... just a silly thought, but LED's do give us the opportunity to think on a completely different level. It was never this simple with cfl. You need a driver circuit AND a starter circuit with them.
 

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Bob Sanders said:
Actually LED's don't have to be anywhere near as expensive as they are now. They cost pennies to make. It's all the driver curcuitry that has to be used to make it compatible with our older style of electricity and delivery system If LED lighting ever becomes standardized then you could run a single central power supply, perhaps one on each floor and they would in turn supply all the power for all the led's on that floor. Bulbs would be MUCH cheaper because they would no longer need the drivers. They would run cooler, and with proper regulated DC power supplies, dimming would be cheaper and smoother and changing a bulb would take place maybe once every 8 or 10 years. Dimming a standard LED bulb with our present method of electrical supply and current type is a bit of a messy business when it doesn't really have to be. Anyways... just a silly thought, but LED's do give us the opportunity to think on a completely different level. It was never this simple with cfl. You need a driver circuit AND a starter circuit with them.
Not happening. That war was waged >100 years ago by Edison and Tesla(Westinghouse). Tesla won. The smart grid is gaining momentum but it's still 60Hz AC to consumers.

LEDs bulbs are just a couple years old. Give the industry a few years to run down the experience curve and prices will fall. They don't need to match incandescent in price but the gap has to close further for everyone to jump in. It's still an early adopter market. I really like the new Philips bulbs that vary color temp as you dim them. Full on they are 2700 but drop to 1800 or so at lowest setting. Better matches an incandescent dimming experience. Still too pricey though at $20 a pop.


Also all the dirty little secrets of dimmer compatibility, buzzing, $100-150 specialty dimmers, and drop out has to improve as well for massive adoption of LED. There's too much fine print on packaging which results in high returns. Retail returns kill a business model. It's not if anymore, just when....
 

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If the bulb says 60-watt equivalent, that's for the measure of lumens, correct?
As the other poster suggested, some manufacturers are very liberal in their claims of "equivalent".

If you want to know how much light they produce -- look at their "lumens" spec.

If you want to know how much power they use -- look at their "Watts:" spec. And by the way, a 100 Watt light bulb makes exactly the same amount of heat as a 100 Watt electric heater. So if you live in Arizona, you are paying twice for the power, once for the 100 watts to light your kitchen, and then for your air conditioner to pump the heat outside.
 
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