Light fixture wattage limit Halgen vs Incandescent

[Naomi Cezana]

Hi,

I am a little confused. If someone with electrical experience can answer, I would appreciate it.

I have a ceiling light fixture that has space for two bulbs. It states that the wattage limit is 60W per bulb. Now with everyone using Halogen bulbs, can I place 2x 53W Halogen Bulbs - which produce the same lumens as a 75W i ncandescent bulb, or do I need to ensure that the lumen output does not exc eed that of the 60W incandescent, which would mean a 43W Halogen bulb?

I hope the question makes sense. I know that halogens produce more heat tha n incandescent, so I am not sure what the Wattage limit is about - is the t he heat that is produced, or is it about the energy that is drawn?

I would appreciate a response - dont want to take any risks, but would love to maximise the lumen output.

Please note, only Halogen or Incandescent bulbs can be used in this specifi c fitting.

Thank you in advance.

[Nate Nagel]

The wattage limit is for heat concerns - one, the heat produced by the bulb in the fixture, and two, the heat produced by the resistance of the wiring/sockets in the fixture as the current flows through it (hopefully negligable at rated power.)

I would consider the 60W/bulb limit to be a limit for any type of bulb no matter what (BTW halogen is a subset of incandescent) if you want to make sure that your setup is safe check temp with 2x 75W incandescents and then check again with 2x 53W halogens, if the temp with the halogens is the same as or lower than the temp with the incans you are not outside the design parameters of the light.

In this case I think you are probably quite safe; there have been some concerns about heating with CFLs due to their producing more heat in their bases and trapping it there as opposed to in the globe of the bulb as in an incandescent, but since incan and halogen are essentially the same thing and operate the same way I really don't see how the fixture would get hotter with a lower wattage halogen.

good luck,

nate

[Pat]

Hi Naomi, You ask a very good question. The 60 Watt limit is probably related to the heat generated by the bulbs but could also be the current limits of the sockets and wires. Only the original designer would know for certain. Assuming it is the heat, new technologies like CFLs and LEDs would be fine if they physically fit. They produce significantly less heat AND draw significantly less current. Halogens, as you say, are designed to run hot. That could be a problem. If the replacement bulbs you are looking at are designed to directly replace incandescents, the 53 watt models are probably OK. The hot filaments are probably well within the overall enclosure of the bulb. Since halogens are more efficient than incandescents, the overall heat entering the fixture is less than an incandescent of the same wattage. In summary, I am "pretty sure" the 2x53W Halogens Bulbs would work safely, but I can't say 100% sure. I can say that lumens are not the problem.

Pat

[trader4]

+1

[Ralph Mowery]

It is the heat that is produced. For even 200 watts of power, almost any wire that is big enough to attach to other wires will handle the current. Often the rating is for the ammount of heat the wire is rated for.

Light bulbs generate that ammount of heat the wattage is rated for. In a room all the enegery is converted to heat. Not counting a few photons of light that may exit a window which would not be enough to measure by any practical means.

Some fixtures will move the heat away from them beter than others.

[Tony Hwang]

+1 again. Lumen has nothing to do with heat. Watt does.

[Tony Hwang]

Hmmm, You are trying to say 53W has more heat that 60Watt? Do the math.

[Tomsic]

I am a little confused. If someone with electrical experience can answer, I would appreciate it.

I have a ceiling light fixture that has space for two bulbs. It states that the wattage limit is 60W per bulb. Now with everyone using Halogen bulbs, can I place 2x 53W Halogen Bulbs - which produce the same lumens as a 75W incandescent bulb, or do I need to ensure that the lumen output does not exceed that of the 60W incandescent, which would mean a 43W Halogen bulb?

I hope the question makes sense. I know that halogens produce more heat than incandescent, so I am not sure what the Wattage limit is about - is the the heat that is produced, or is it about the energy that is drawn?

I would appreciate a response - dont want to take any risks, but would love to maximise the lumen output.

Please note, only Halogen or Incandescent bulbs can be used in this specific fitting.

Thank you in advance.

This one is straightforward. The 60 watt x 2 limit is based upon heat via a UL test based upon standard UL-1598. The lumen output of the lamps doesn't matter.

Tomsic

[Nate Nagel]

Agreed, and less expensive light fixtures may not be rated for an incan wattage that will put out enough light to properly light the room. Check the stickers when purchasing - many fixtures spec a maximum of 40 or 60 watts, even if it's a big fixture. Table lamps are just as bad.

I was pleasantly surprised with the Philips L-Prize "60W equivalent" LED "bulbs" which are actually slightly brighter than a traditional 60W bulb. Of course I became aware of them, bought a few, liked them, then they were promptly discontinued. you can still buy them on Amazon, but at around $40 apiece... they were $15 at Home Despot for a while, but you had to find a store that had them.

nate

[bud--]

Or compare 2x 60W with 2x 53W halogen. Comparing may not be easy.

With the more efficient halogen, presumably you could use a larger actual wattage and the actual heat could be lower than an regular incandescent because a lower percent of the halogen wattage winds up as heat. Not sure I would want to try that without heat comparisons for an enclosed fixture.

Halogen filaments are hotter than regular incandescents, but these have a halogen capsule that is inside a glass bulb.

My recollection from Don Klipstein is that the heat produced by a CFL is at wavelengths that do not radiate as well as the heat from incandescents, and the globe enclosing a CFL may be hotter than an incandescent. The electronics in a CFL is much more heat sensitive.

The halogen capsule is at a higher temperature and my guess is it would radiate heat a little better than a regular incandescent.

[bud--]

I agree it is heat, not current. A minor addition for people not familiar with wire ratings - it is the heat rating of the insulation of the wire.

Heat is an issue not only for the lamp wiring, but the building wiring behind the fixture.

Heat is also a major issue for the socket.

Would seem like 2 - 53W halogens would be OK.

===================================== CFL, and particularly halogen, lamp manufacturers have a habit of lying about what is an equivalent wattage. A 75W regular incandescent should be at least 1100 lumens. (For a 60W - 800 lumens, 100W - 1600 lumens.)

[Frank]

In two kitchen, enclosed fixtures that specified 60 watt incandescent bulbs, I've been using 75 watt equivalent CFL's with no problem for several years. Both fixtures with glass globe on one and cover on another are a PITA to change and CFL's have largely eliminated this concern with their much longer lifetimes.

[Percival P. Cassidy]

To the best of my knowledge, halogen bubs run hotter than regular incandescents.

Perce

[jamesgang]

Halogen are slightly more efficient than tungsten so watt for watt they should produce slightly less waste heat.

[Nate Nagel]

My thought as well. There may be slightly different mechanisms for shedding the waste heat as a halogen has an extra capsule inside the globe, but overall halogen and regular incan are very, very similar so I would expect them to behave roughly similarly.

If you are really worried about "pushing the limits" checking with a laser guided non-contact thermometer should provide reassurance. (sounds expensive, but Harbor Freight sells 'em for cheap. I had a good one that I picked up somewhere but I'll be damned if I can find it anywhere.)

nate

[Naomi Cezana]

Thank you Everyone, it seems the consensus is that it would be ok to install the 53W halogens... Hope it works out!

[Ralph Mowery]

All light bulbs produce the same ammount of heat for the same ammount of wattage drawn from the line. Atleast with any common means to measure the ammount of heat.

Some bulbs may have a smaller area where the power is used and may heat one spot on the bulb hotter than another. In a closed fixture the ammount of heat will be the same.

The compact flouresent bulbs give off more light than a filiment type bulb for the same ammount of power used. That is why the CFL draws less than 20 watts while producing the same ammount of light as a 60 or 75 watt filiment bulb.

[Pat]

No, I am not saying that. I am saying a halogen bulb that wasn't envisioned by the designer could concentrate heat in a different place and therefore cause a problem. I agree that is very unlikely.

My thinking is similar to LED heat issues. Even though an LED produced much less heat than an incandescent of similar light output, the little heat that is generated is all in one place - the LED itself

- rather than being radiated away from the bulb. That is why higher brightness LEDs have been slow arriving to market. Creative heat sinks are solving the problem - slowly.

Pat