I have just decorated my hobby room and need a new ceiling light shade which will take 100w (or new equivalent 14-16 LED) bulb. I need the bright light for close work but all the suppliers I have tried only seem to keep shades using 60w or equivalent in LED. Can anyone advise where I may be able to get a shade to take the brighter bulbs? Many thanks.
Lamp Shades
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what country are you in?
the amount of heat a bulb gives out is proportion to the electrical power running through it.
So a 15W LED is cooler than a 60W filament, even though it gives out more light than a 100W filament.
For some reason lampshade manufacturers do not all understand that.
Anyway, I'd go for an Anglepoise or spots over the workbench.
the amount of heat a bulb gives out is proportion to the electrical power running through it.
So a 15W LED is cooler than a 60W filament, even though it gives out more light than a 100W filament.
For some reason lampshade manufacturers do not all understand that.
Anyway, I'd go for an Anglepoise or spots over the workbench.
Not necessarily cooler. The 60 W filament radiates most of that 60 watts from the glass envelope's large surface area. The heat generated in the LED lamp is concentrated in the components of the LED driver and these are invariably packed into the small space inside the bayonet or screw cap which therefore gets hot and thus the lamp holder gets hot.
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And so does the bulbholder of a 60W filament lamp, which generates much more heat.
I'm sure you've seen lampshades, curtains or paper that have charred or even caught fire in contact with a filament lamp.
But a 15W LED?
A bulbholder that can cope with the heat of a 60W filament will easily cope with the far smaller heat of a 15W LED. So will the lampshade.
Yes I have seen scorched lamp shades, I have also replaced lamp holders damaged ( scorched ) by heat from "energy saving" lamps.
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I have lost count of the number of pendant lamp holders I have replaced in the last 35 years (many due to old folk replacing the 60W lamp with a 150W GLS...)
How many have you replaced because the 60W lamp has been replaced by a 10-15W LED?
It seems to me that two different things are getting muddled here ...
Although an LED will consume much less power, and generate less heat, than a similar-luminance incandescent bulb, the heat tends to be concentrated around the base (rather than primarily radiated from the 'capsule' of the bulb), and LEDs are much more susceptible to thermal damage than incandescents - hence the maximum power of LED that should be used in a particular fitting will usually be a lot lower than the maximum power of incandescent bulb that should be used in the same fitting.
However, as far as the great majority of shades are concerned, it is the heat radiated from the capsule of the bulb that matters - so, from that point of view, a shade should be able to tolerate a higher wattage of LED than incandescent (not that LEDs will ever be anything like that high powered) - so it seems to make little sense that shade manufacturers should specify a lower 'maximum wattage' for LEDs than for incandescents.
Kind Regards, John
Although an LED will consume much less power, and generate less heat, than a similar-luminance incandescent bulb, the heat tends to be concentrated around the base (rather than primarily radiated from the 'capsule' of the bulb), and LEDs are much more susceptible to thermal damage than incandescents - hence the maximum power of LED that should be used in a particular fitting will usually be a lot lower than the maximum power of incandescent bulb that should be used in the same fitting.
However, as far as the great majority of shades are concerned, it is the heat radiated from the capsule of the bulb that matters - so, from that point of view, a shade should be able to tolerate a higher wattage of LED than incandescent (not that LEDs will ever be anything like that high powered) - so it seems to make little sense that shade manufacturers should specify a lower 'maximum wattage' for LEDs than for incandescents.
Kind Regards, John
I am currently refurbing a 1 bed flat, there are total of 4 pendants and one batten holder, the only holder that didn't actually need replacing due to heat damage was the one containing a 60W GLS, the others all had 11W CFL's dated 2011 [I got into the habit of marking the fitted dates due to the early reliability issues]. 2 of the holders simply disintegrated when I tried removing the CFL.
I find the CFL body where the heat is concentrated is almost touching the lock ring whereas there is usually 3-4 mm clearance with a GLS so my theory is the conducted heat causes more damage than the convected. This may not be relevant with LED lamps.
I find the CFL body where the heat is concentrated is almost touching the lock ring whereas there is usually 3-4 mm clearance with a GLS so my theory is the conducted heat causes more damage than the convected. This may not be relevant with LED lamps.
I think that is almost certainly true, of both CFLs and LEDs, in the latter case with the additional problem that the LED elements are particularly heat sensitive.
However, as I recently wrote, as far as shades are concerned (which, after all, is meant to be the topic of this thread), it is surely the radiated (and to some extent convected) heat which matters, and that is going to be much greater with an incandescent bulb/lamp than with a CFL or LED even of the same power (which will not happen in practice)?
Kind Regards, John
Generally I agree, many of the shades have plastic rings for the lampholder these days and I wonder if that comes into it? Additionally I wonder if the higher UV content of CFL's and LED's has any relevance, it certainly discolours the plastic quicker.
I suppose it might, given that CFLs/LEDs can certainly get pretty hot 'down there' - but I can't say I've got any shades young enough to have other than metal rings, so I didn't think of that
Kind Regards, John
If the shade is trapping the heat in a Cfl, could be more affected by that heat, even though its a lot less heat than from a tungsten lamp, whereas a tungsten lamp can withstand that same heat plus lots more.
Even Tungsten 100w bulkhead fittings advise against fitting Cfl lamps
Even Tungsten 100w bulkhead fittings advise against fitting Cfl lamps
The plastic rings i have seen usually snap out, the brackets are made in metal to fit Continental lampholders, and the snap in plastic removable insert reduces them to 22mm for UK use
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