cfls in fixtures designed for incandescent lamps

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wire twister

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Might sound like a stupid question but all my work is commercial/industrial so I have never ran into this situation before. I am looking at changing out the 60w incandescent lamps in my enclosed ceiling fixtures with 13 or 20 watt cfls, but I was wondering about the heat buildup. Are there any concerns as far as heat buildup safety wise or longevity wise?
 
masterinbama said:
Heat is not a problem. The only problem I have encountered is some are restricted as to what orientation they can be used. I.E. horizontal, straight up or straight down.
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Also, if you have dimmers, they can be a problem. The bulbs need to be dimmable, and in some cases the dimmer must be for CFL.
 
masterinbama said:
Heat is not a problem. The only problem I have encountered is some are restricted as to what orientation they can be used. I.E. horizontal, straight up or straight down.
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Heat is not a problem, Then why would orientation be an issue?

HEAT!
 
Look at the fine print on cfl lamps. I have yet to see one that can be installed in an "enclosed" fixture. The only real place that they can be used, is in lamps or open fixtures.

I still have used them in enclosed fixtures, but they go bad prematurely.
 
wire twister said:
Might sound like a stupid question but all my work is commercial/industrial so I have never ran into this situation before. I am looking at changing out the 60w incandescent lamps in my enclosed ceiling fixtures with 13 or 20 watt cfls, but I was wondering about the heat buildup. Are there any concerns as far as heat buildup safety wise or longevity wise?
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Heat build up is an issue. CFLs can't reject heat by radiant energy, so it will get hotter than its designed for and fail prematurely.
 
Electric-Light said:
Heat build up is an issue. CFLs can't reject heat by radiant energy, so it will get hotter than its designed for and fail prematurely.
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I thought that the heat thing was all BS until I put one in a shower trim fixture and it was burned out by the next day. Of course I thought that maybe it was just a bad bulb and the second one didn't last much longer.
 
cowboyjwc said:
I thought that the heat thing was all BS until I put one in a shower trim fixture and it was burned out by the next day. Of course I thought that maybe it was just a bad bulb and the second one didn't last much longer.
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Take two identical CFLs, enclose one, run one in the open. When you notice the enclosed one turning higher in CCT (kelvin), then you know that its overheating.

When CFLs overheat, not only do they fail early, the efficacy drops dramatically.
 
Electric-Light said:
Take two identical CFLs, enclose one, run one in the open. When you notice the enclosed one turning higher in CCT (kelvin), then you know that its overheating.

When CFLs overheat, not only do they fail early, the efficacy drops dramatically.
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And the orientation makes a difference primarily because the most heat sensitive part (in terms of life) is the electronics module at the lamp base, while much (but by no means all) of the heat comes from the tube rather than internally from the electronics.
 
Imo the cfl is a waste of money. I was given 3 or 4 from the local power company and they all burned out within a few months. These bulbs were not on all day but rather 3 or 4 hours a day max. They were installed in an open track head. I think heat is an issue and also the style of light that the fixture demands is important.

The other issue is the listing. I have never seen anyone get called on it but the fixture is listed for incandescent luminaires -- in most cases.

I have a customer who bought all these LED tube fixtures so he can convert his fluorescents to LED's. Called the inspector and he said -- NO Way. You void the listing when you disconnect the ballast or modify the fixture
 
Dennis Alwon said:
Imo the cfl is a waste of money. I was given 3 or 4 from the local power company and they all burned out within a few months. These bulbs were not on all day but rather 3 or 4 hours a day max. They were installed in an open track head. I think heat is an issue and also the style of light that the fixture demands is important.

The other issue is the listing. I have never seen anyone get called on it but the fixture is listed for incandescent luminaires -- in most cases.

I have a customer who bought all these LED tube fixtures so he can convert his fluorescents to LED's. Called the inspector and he said -- NO Way. You void the listing when you disconnect the ballast or modify the fixture
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For screw base fixtures, I am used to seeing a warning about the maximum wattage Type A or Type R lamp you can put in them, but I don't have access to the UL book to see whether there is a hidden listing condition that they must be incandescent bulbs. (For that matter, I wonder if a 60 watt halogen Type A might cause higher temperatures in the fixture than a common incandescent.)
Modifying the ballast in a listed fixture is a lot more invasive than just screwing in a different kind of lamp.
 
buzzbar said:
Look at the fine print on cfl lamps. I have yet to see one that can be installed in an "enclosed" fixture. The only real place that they can be used, is in lamps or open fixtures.

I still have used them in enclosed fixtures, but they go bad prematurely.
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I just looked at one last night, and it basically said not for use in "totaly enclosed recessed fixtures." So a surface mounted light, or a recessed light without a lens would be OK.

I can't see a 13 watt lamp and ballast getting nearly as hot as a 60 watt incandescent. But the ballast probably has a lower temp. limit than an incandescent lamp would have.
 
steve66 said:
I just looked at one last night, and it basically said not for use in "totaly enclosed recessed fixtures." So a surface mounted light, or a recessed light without a lens would be OK.

I can't see a 13 watt lamp and ballast getting nearly as hot as a 60 watt incandescent. But the ballast probably has a lower temp. limit than an incandescent lamp would have.
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That is the issue. The CFL's will not overheat the fixture as they do not get as hot as an incandescant, but they still produce heat and are not designed to operate where that heat will be trapped increasing the ambient temp of the lamp and ballast.
 
kwired said:
That is the issue. The CFL's will not overheat the fixture as they do not get as hot as an incandescant, but they still produce heat and are not designed to operate where that heat will be trapped increasing the ambient temp of the lamp and ballast.
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I don't think that's entirely true.
I just purchased 2 totally enclosed outdoor wall sconce lights from Acclaim Lighting that are listed for a 13W GU24 CFL lamp and even came with the lamp.
 
Little Bill said:
I don't think that's entirely true.
I just purchased 2 totally enclosed outdoor wall sconce lights from Acclaim Lighting that are listed for a 13W GU24 CFL lamp and even came with the lamp.
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GU24 based lamps maybe have different design that can take the heat? I have seen them in other enclosed fixtures as well. I have also seen that a fixture designed for 13W GU24 will not have enough room to put cover back on if you try to install a larger wattage lamp - probably for good reason.
 
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