Lighting 101, basic but...
- Thread starter Calvados
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That will be the maximum for a CFL energy saving lamp. If you can get an LED that fits it will give more light than a CFL.
13W!
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The maximum rating of 60W is based on the heat output, usually limited by the shade fitted.
The comparison with low energy types is nonsense - 13W is just some useless conversion indicating a similar light output.
A 60W CFL could be fitted if it would physically fit in there.
The fitting/shade doesn't know whether its a CFL, LED or anything else.
The comparison with low energy types is nonsense - 13W is just some useless conversion indicating a similar light output.
A 60W CFL could be fitted if it would physically fit in there.
The fitting/shade doesn't know whether its a CFL, LED or anything else.
Yes, good point! I should have thought about that before posting 
You may use a 150W CFL if it will fit*, on the grounds that they produce far less heat than incandescents.
i.e. the heat output of a 60W CFL is nowhere near as much as that of a 60W incandescent.
* Which it surely won't - a 150W CFL is huge.
Basically, the biggest CFL you can get in there will be absolutely fine - you don't need to worry about heat. Do check the instructions for any lamps you look at - I don't know what orientation it has in your fittings, but not all CFLs are happy base-up.
i.e. the heat output of a 60W CFL is nowhere near as much as that of a 60W incandescent.
* Which it surely won't - a 150W CFL is huge.
Basically, the biggest CFL you can get in there will be absolutely fine - you don't need to worry about heat. Do check the instructions for any lamps you look at - I don't know what orientation it has in your fittings, but not all CFLs are happy base-up.
Comparing heat produced in an incandescent lamp with heat produced in a Compact Fluorescent Lamp ( CFL ) shows that it is not as simple as it seems.
The heat from the incandescent lamp comes almost entirely from the large area of the glass and not the cap ( screw or bayonet end of the lamp )
Most of the heat created in CFL lamps is created by the electronics in the cap of the lamp and thus the heat is more concentrated in the lamp holder and is not dissipated by the air flow over the glass.
Hence the reason why some ( many ) CFLs are not happy "base up", they over heat.
That's all true, but once you introduce the inevitable size constraints the OP will have, I really don't think he has to worry about where the heat is produced in the lamp, wrt to damage to the lampholder or shade, as there will be so little of it.
AFAIK an incandescent lamp turns about 90% of the energy it consumes into heat, and a CFL about 30%. So a 20W CFL will produce, not as much heat as a 20W incandescent, but as much as a 7W one. Whatever will fit in the OPs lights will be fine.
AFAIK an incandescent lamp turns about 90% of the energy it consumes into heat, and a CFL about 30%. So a 20W CFL will produce, not as much heat as a 20W incandescent, but as much as a 7W one. Whatever will fit in the OPs lights will be fine.
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Oh is wish it was that simple. I have an 11W CFL with 900 lm output classed a A with a G23 base it is likely as good as any LED lamp. But most 11W CFL are no where near that output of light.
Clearly the more light the less heat but my folded tube is not used with a BA22d fitting and if one wants to run on the limits then you have to consider the heat of the lamp used.
So moving beyond the manufactures recommended sizes it's up to you to decide if that unit can take the heat and it's no good trying to move the responsibility if you want to exceed the manufactures recommendations it up to you and no one else to work out if it's OK.
Clearly the more light the less heat but my folded tube is not used with a BA22d fitting and if one wants to run on the limits then you have to consider the heat of the lamp used.
So moving beyond the manufactures recommended sizes it's up to you to decide if that unit can take the heat and it's no good trying to move the responsibility if you want to exceed the manufactures recommendations it up to you and no one else to work out if it's OK.
Well - I'd stake what's left of my pension that that guideline was written by somebody who didn't have a clue, and all they did was to see somewhere that an 11W CFL is "equivalent" to a 60W incandescent, and decide that therefore 13W should be the limit for CFLs in their product.
Thanks guys - really glad I asked the question because the sticker on the lamp is clearly advising (incorrectly) that a CFL cannot be more that 13W (hence my question) with the shade/lamp.
But I now understand that I could add the 20W CFL that we really need in that lamp to make the room brighter. So thanks!
But I now understand that I could add the 20W CFL that we really need in that lamp to make the room brighter. So thanks!
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