Choosing the right led bulb.

ChrisinShropshire

ChrisinShropshire

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I have been looking at replacement luminaries for the wall outside our French windows.
For the ones we like, the box says E27, 10 W led. The data sheet on the manufacturer's website says 60W max.
I presume the 60W limit is due to heat build up from an incandescent bulb within the enclosed (IP54) housing. If so, why can't I fit a 12W led as it wont get anything like as hot?

The same applies with lampshades. Some, understandably have a max bulb power for incandescent bulbs, but then put a low limit for less, even though they produce much less heat.

Please can someone throw some light on the subject (sorry for the awful pun)?
 
Once again manufacturers or the people who write for them getting it wrong.
 
ChrisinShropshire said:
I have been looking at replacement luminaries for the wall outside our French windows.
For the ones we like, the box says E27, 10 W led. The data sheet on the manufacturer's website says 60W max.
I presume the 60W limit is due to heat build up from an incandescent bulb within the enclosed (IP54) housing. If so, why can't I fit a 12W led as it wont get anything like as hot?

The same applies with lampshades. Some, understandably have a max bulb power for incandescent bulbs, but then put a low limit for less, even though they produce much less heat.

Please can someone throw some light on the subject (sorry for the awful pun)?
Click to expand...
If you want to get the right answers you have to ask the right questions.

ChrisinShropshire said:
For the ones we like, the box says E27, 10 W led.
Click to expand...
It is possible that what you mean is "The lamps which we would like to use in the existing fitting concerned are designated as "E27, 10 W led"
Of course E27 is the current description of a "Standard" Edison Screw (ES) lamp base - which is nominally 27 mm in diameter.
(The "equivalent" B22 "Bayonet" base is nominally 22 mm in diameter.)
ChrisinShropshire said:
The data sheet on the manufacturer's website says 60W max.
Click to expand...
By this, it is possible that you mean "The data sheet on the manufacturer's website relating to the existing luminaries for the wall outside our French windows says 60W max."

The fittings concerned are all rated for the maximum possible "heat" which they can withstand.
30 years ago, point source lighting was only/mainly obtainable from incandescent lamps.
Now, after enduring a CFL phase, we have LED lamps which are at least 5 times more efficient in producing Light than were Incandescent lamps, which mainly produced heat.

Everyone must get used to specifying light output in Lumens - and not "Equivalent Watts", as seems to be prevalent in North America.

As a "bench mark", an efficient Incandescent 60W lamp might have produced about 800 Lumens.
However, a 800 Lumen LED should use only not more than 10 W, or (with increasing efficiency) less.

There can be arguments as to how light is distributed from the LED lamps concerned as opposed to the light distribution from incandescent lamps, but that is another story.
 
Last edited:
Leds do still get hot, its quite possible that a 10w led can generate enough heat to destroy its electronic components rather than the light fitting
 
FrodoOne said:
If you want to get the right answers you have to ask the right questions.


It is possible that what you mean is "The lamps which we would like to use in the existing fitting concerned are designated as "E27, 10 W led"
Of course E27 is the current description of a "Standard" Edison Screw (ES) lamp base - which is nominally 27 mm in diameter.
(The "equivalent" B22 "Bayonet" base is nominally 22 mm in diameter.)

By this, it is possible that you mean "The data sheet on the manufacturer's website relating to the existing luminaries for the wall outside our French windows says 60W max."




The fittings concerned are all rated for the maximum possible "heat" which they can withstand.
30 years ago, point source lighting was only/mainly obtainable from incandescent lamps.
Now, after enduring a CFL phase, we have LED lamps which are at least 5 times more efficient in producing Light than were Incandescent lamps, which mainly produced heat.

Everyone must get used to specifying light output in Lumens - and not "Equivalent Watts", as seems to be prevalent in North America.

As a "bench mark", an efficient Incandescent 60W lamp might have produced about 800 Lumens.
However, a 800 Lumen LED should use only not more than 10 W, or (with increasing efficiency) less.

There can be arguments as to how light is distributed from the LED lamps concerned as opposed to the light distribution from incandescent lamps, but that is another story.
Click to expand...


My concern is that I have to buy a bulb for the new luminaire. It has an E27 fitting, so I know I need a bulb with the appropriate Edison fitting. There are two sources of information about the bulb that I should buy. The manufacturer's website says '60W max'. The box that the luminaire came in says '10W led max'.
Even a 1300 lumen led bulb won't produce as much waste heat as a 60W incandescent bulb, will it?
 
FrodoOne said:
Everyone must get used to specifying light output in Lumens - and not "Equivalent Watts", as seems to be prevalent in North America.

As a "bench mark", an efficient Incandescent 60W lamp might have produced about 800 Lumens.
However, a 800 Lumen LED should use only not more than 10 W, or (with increasing efficiency) less.
Click to expand...

The problem there is so much stuff coming from the far east that completely lies about lumens, and even more annoying, will lie about wattage too!


ChrisinShropshire said:
My concern is that I have to buy a bulb for the new luminaire. It has an E27 fitting, so I know I need a bulb with the appropriate Edison fitting. There are two sources of information about the bulb that I should buy. The manufacturer's website says '60W max'. The box that the luminaire came in says '10W led max'.
Even a 1300 lumen led bulb won't produce as much waste heat as a 60W incandescent bulb, will it?
Click to expand...

How bright do you need it to be? Sometimes just a few watts from an LED bulb is enough to see your way. Maybe even look at dusk til dawn, or motion sensor bulbs
 
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