Let's shed some light on the situation
February 17, 2019 2:31 PM   Subscribe

It dawns on me (ha) that I have somehow become so afraid of putting too-high wattage bulbs in lamp sockets that my house is.... dim. Am I being silly?

Can I put a 60W bulb in a socket labeled as 45W? Can I put in 75w? 100w? Some bulbs need to go in sconces/chandeliers (does it matter if the wiring is in the wall?) and others are normal, non-antique table lamps.

FWIW I far prefer incandescents to CFL, LED or others (which are so hard - for me - to dispose of and don't come in the necessary weird sizes/shapes).

Please let me know if the "recommended wattage" is a laughable marketing ploy... or something that real adults know to follow like gospel.
posted by nkknkk to Home & Garden (29 answers total) 5 users marked this as a favorite
 
The sockets are rated for a particular bulb. You should not exceed the socket rating. However, LEDs are ridiculously efficient and are THE WAY to get a lot of light out of low-rated sockets. I know you said you prefer incandescents, but modern LEDs are much more pleasant than even a few year old ones.
posted by Gilgamesh's Chauffeur at 2:48 PM on February 17 [9 favorites]


You can put a higher lumen-equivalent LED in cheap lamps because the bulbs generally use < 15W. The wattage rating in a lamp is a calculation essentially based on the size of the wire used in it and the amount of electricity that's going to run through it, not the brightness of the lamp per se.
posted by rhizome at 2:49 PM on February 17 [3 favorites]


I accidentally put a 50W bulb in a fixture that said 35W max.

It exploded one day at breakfast, and a piece of hot glass fell on my daughter's hand.

I am now more careful about following the stated ratings.
posted by clawsoon at 2:52 PM on February 17 [7 favorites]


And yeah, I used to be an incandescent snob who traveled for miles around to collect 100W incandescents when they got banned here several years ago. After my stash ran out I started looking at new technologies, and I've been very happy with the color temperature of the LEDs I've been able to find, much more so than 5 years ago. CFLs are straight-up losers no matter how you slice it.
posted by rhizome at 2:52 PM on February 17 [12 favorites]


Light bulbs put out a lot of heat. The more light, the more heat. This means that anything close to the light bulb (socket, wiring, the fixture itself) needs to be able to withstand this heat. The maximum wattage on any fixture corresponds to the maximum amount of heat that the manufacturer guarantees will not set the lamp/fixture on fire.

Incandescents actually emit something like 80–90% of their energy as heat, and relatively little as visible light. You can get more light out of a given lamp or fixture by using an LED or CFL bulb, since they emit more light for the same amount of heat. If you look on the packaging for such a bulb, it will usually be sold as "100-W equivalent (25 W)"; it's the smaller number that is the one you need to worry about for safety purposes.
posted by Johnny Assay at 2:56 PM on February 17 [7 favorites]


The rated wattage of a fixture is decided by the heat production of a similarly-rated incandescent bulb. Never "over-lamp" a fixture with incandescent bulbs. Clawsoon's story is on the low-consequence side of what can happen; some fixtures will catch fire or set adjacent objects on fire.

Fortunately, modern LED bulbs are quite good, and there's no problem putting a 100W "equivalent" LED bulb in a 60W incandescent rated fixture, especially because that 100W "equivalent" LED bulb is going to draw far less than even half of its incandescent ancestor, so you can get brighter light.

For the best LED light in multiple socket fixtures, use a combination of "warm" and "daylight" bulbs. This gives a very natural moderately warm tone. This is particularly effective in bathrooms and kitchens where you want lots of high quality light.

I'm fussy about light, and I use LEDs now after gritting my teeth at CFLs.

There's no excuse not to switch any more.
posted by seanmpuckett at 3:00 PM on February 17 [6 favorites]


Immediately after the wattage rating on the label are the words “RISK OF FIRE.”

Your lighting fixture has only been safety tested to the wattage listed on the labels. If the wattage is lower than it could be, that’s possibly because they tried it with higher wattage bulbs and it failed.
posted by Huffy Puffy at 3:16 PM on February 17 [3 favorites]


If the socket says 45W max, you can't go past that without risking a fire. That's a real thing. Now, there may not be that much risk depending on how far above its limit you go, but there's a reason those ratings exist and if you exceed them then all bets are off as far as the manufacturer is concerned.
posted by Anticipation Of A New Lover's Arrival, The at 3:18 PM on February 17 [2 favorites]


I once put 100W incandescent bulbs in a lamp rated for 60W. I was able to unplug it before it caught fire, but not before it started to put out smoke. I was very stupid and very lucky.

All the lamps in this place are rated for 60W max, but I have 100W-equivalent bulbs in them because the LED 100W equivalent is actually only 14W. The labeling is confusing but if you look at the label closely you’ll see it’s fine.
posted by Ampersand692 at 3:18 PM on February 17 [4 favorites]


It's just lumens and color for me now. I think a 60w equivalent is about 850 lumens? At any rate they're fairly well segmented at retail so it's easy to figure out which strength the bulb is when looking at boxes.
posted by rhizome at 3:33 PM on February 17


I hate CFLs, but modern LEDs are very low-flicker and come in a wide range of colour temperatures. It's not hard to find ones that match the "feel" of incandescent bulbs closely. Not at all like even five years ago, when "cool white" was almost the only option.
posted by tobascodagama at 3:42 PM on February 17


An additional note: LED bulbs are just as easy to dispose of as incandescents, as that's a point you mentioned. Some of the bulbs I have can even be easily disassembled for better recycling - I've easily separated the glass lens, the metal heatsink, and the plastic housing for the electronics.
posted by mhz at 4:23 PM on February 17 [4 favorites]


Another vote urging you to respect the rated wattages on your sockets. A couple other minor additions to the LED recommendations above: to get the LEDs that best match incandescent bulb light, you have to shop by color temperature, as noted above. Not specified above, though, is the color temperature to look for: about 2700K, or as close to that as you can. I've never really seen anything lower, but colors up to 2850K will probably look fine. This is also known as "warm white" or "soft white" in many brands. Second, LEDs have no harmful chemicals - unlike CFLs - and so they can be tossed in any garbage or even recycled with mixed plastics.

Finally, I feel you about odd bulb sizes. If online shopping is an option for you, search for "chandelier LED bulbs"; there appear to be many options both at Amazon and at custom vendors. Some of them even have thin semiconductor "filaments" so they resemble Edison bulbs instead of newfangled LEDs. Pretty cool.
posted by Joey Buttafoucault at 4:27 PM on February 17 [1 favorite]


From what i understand, the the maximum rating considers not just heat the bulb makes, but maximum safe power draw through the fixture’s wiring. An overheating wire or other electrical connection could seem fine for a long time (years, even) before eventually resulting in a fire. I’d not push my luck.

If you haven’t already, switch to the halogen bulbs that are packaged in a traditional bulb but put out the equivalent in lumens of a higher watt bulb. E.g., the ones i use are 72 watt bulbs and are the rough equivalent of a 100 watt incandescent. This is great for my lamps that are rated for 75 watts maximum. (I live in a cold, rainy climate where the heat is usually on at night even in the summer. Bulb heat just means my heater has to work less.)
posted by D.C. at 4:51 PM on February 17


Hard to find bulbs?
Try bulbster They carry LED
I had a heck of a time finding bulbs for an old microscope till I found them.
posted by rudd135 at 4:52 PM on February 17 [1 favorite]


All of the above on the safety of running high-brightness, low-wattage LED bulbs in low-wattage fixtures is completely correct, but if you've tried LED lighting and not liked it that's probably not because there's something wrong with you; it's probably because LED lighting will alter the way your interior colours appear compared to similarly bright incandescent lighting, and it takes time to get used to that.

The colour spectrum out of a LED or CFL bulb is designed to make whites and greys appear to be the same colour as when illuminated by an incandescent source with a similar colour temperature rating. The term "colour temperature" refers to the spectrum of radiant emission from an ideal black body heated to the specified temperature; the heated filament of an incandescent bulb is a very good approximation of an ideal black body at around 2800K, which is also a typical colour temperature for a "warm white" CFL or LED bulb.

Black body radiation is a continuous spectrum. If you use a prism to make a rainbow out of it, you will see the rainbow colours shade smoothly into one another and there will be no sharp bright lines visible. Do the same thing with a LED or CFL bulb and you will see mostly sharp bright lines: the light out of these devices is not black body radiation.

When used to illuminate whites and greys, or when used to create perceived colours directly by additive synthesis as is done by every flat panel display screen, this difference makes no difference: careful choice of the colours and intensities of those sharp spectral lines makes their combined effect as perceived indistinguishable from that of the black body radiation they're designed to simulate, because they stimulate the color-sensitive cells on the back of the human retina to the same relative extents.

But if you illuminate coloured objects with them, the reflected light from those objects will in general not stimulate the retina the same way as it would under illumination from continuous-spectrum black body radiation. Sit in a familiar room where you've fitted LED or CFL lighting to replace incandescents, and you will notice that certain colours pop out at you in ways they haven't done before and that the whole room looks subtly "off".

This sudden unfamiliarity is usually experienced negatively by those who notice it at all (many people simply don't) and that's generally what's behind a stated preference for incandescent lighting over anything else.

It used to be the case that non-incandescent lighting would flicker at mains frequency to a much more perceptible extent than incandescent lighting would, causing discomfort in people sensitive to subtle flicker. Old-style tube fluorescent lighting does this quite noticeably as well as featuring a peaky spectrum that messes up colour perception, which is why it has such a terrible reputation.

I don't cope well with flicker, but it's been my experience that leaving new CFL or LED lighting in place and just deciding to put up with the colour differences means that after a few weeks my attention is no longer drawn to them and the rooms look just fine again.

It's also been my experience that bulb manufacturers are getting better at working around the inherently peaky output from their LED and CFL products by using fluorescent substances with many more spectral peaks; these simulate the perceptual effect of black body radiation much better than the earlier products did. In fact I've experienced periods of needing to readjust as room colours shift back to something much more similar to an incandescent-illuminated look after replacing long-serving CFL central room lights with new LED ones.

From what i understand, the the maximum rating considers not just heat the bulb makes, but maximum safe power draw through the fixture’s wiring.

For typical domestic fixtures with maximum rated powers in tens of watts, the bulb heat is really the only limiting factor. Standard house wiring doesn't break a sweat until you start pulling thousands of watts.

Bulb heat is perfectly capable of setting fire to an under-rated fitting without help from the wiring.
posted by flabdablet at 4:59 PM on February 17 [12 favorites]


Standard house wiring doesn't break a sweat until you start pulling thousands of watts.

Yeah, but i was referring to the internal-to-the-fixture electrical path, not the house wiring it is connected to.
posted by D.C. at 5:10 PM on February 17


Even so, I've never seen a fixture whose wiring is so thin that running a bulb ten times the fixture's rated wattage would challenge its current carrying capacity.

Fire-causing failure modes that do involve the wiring will typically be due to excessive bulb heat melting the insulation and causing an arc to develop where the wiring consequently shorts out.

But it doesn't really matter exactly how it happens. Bottom line: it absolutely is unsafe to install a bulb that consumes more electrical power than the fixture you're installing it in is rated for.
posted by flabdablet at 5:16 PM on February 17 [2 favorites]


CFLs are totally different than LEDs in the respects you mentioned being concerned about: disposal, weird sizes, flicker and color. Try LEDs again, they're really totally fine now. They don't need special handling like the mercury does in CFLs, they don't flicker, and you can find them in all the color temperatures you'd want.
posted by odinsdream at 6:00 PM on February 17 [2 favorites]


I meeeeaaan SHOULD you follow the rules? Absolutely! HAVE I broken them my whole light-bulb-replacing life to minimal issue? Yes! I wouldn't stick a 60w in a 35w fixture but a 100w in 75w fixture has been fine for me. However as everyone else is saying, the new LEDs, bright and warm, are actually great.
posted by masquesoporfavor at 6:01 PM on February 17


It's true that you'll have a very hard time finding an LED bulb which will strain the capacity of your sockets to handle heat.

However, all white LED bulbs are actually a kind of fluorescent light in which the LED component emits light with a narrow range of short wavelengths which excites phosphors painted onto the surface of the LEDs, and those phosphors in turn emit a range of longer wavelength light.

Almost all white LED bulbs use blue light LEDs to excite the phosphors, and the power spectrum of the emitted light invariably has a strong peak in the blue region, and in all the spectra I can remember looking at, that blue peak is actually the highest in the entire spectrum, whether it's a warm white bulb or not.

And there are some problems with blue light. It's been known for years now that blue wavelengths are by far the most effective in resetting your circadian rhythms, and they do this via blue sensitive cells in the retinal ganglion layer in front of the image forming parts of the retina, and that's the reason there's so much advice out there to avoid looking at your phone right before bedtime, because the blue light emitted by the phone LEDs can reset your internal clock inappropriately and interfere with sleep.

But a study published last year seems to show that excessive amounts of blue light can actually damage cells in the retina, and potentially lead to serious vision problems over the long term.

But there is one manufacturer which makes white LEDs that use a violet light emitting LED to excite the phosphors, and that would probably ameliorate both problems.
posted by jamjam at 6:19 PM on February 17 [2 favorites]


Fancy stuff:
Small lamp style (also great for stove hood lights)
Chandelier (1, 2)
Edison olde-tymey
posted by rhizome at 7:25 PM on February 17 [1 favorite]


However, all white LED bulbs are actually a kind of fluorescent light in which the LED component emits light with a narrow range of short wavelengths which excites phosphors painted onto the surface of the LEDs, and those phosphors in turn emit a range of longer wavelength light.

I don't think this is really true, though? The part about "all of them" being what you describe. Every LED bulb I've bought or even seen at common hardware stores and Ikea are direct light coming from the LED junction, and perhaps routed through some optical media for diffusion, but none of them I've seen are actually the fluorescent scenario you describe.
posted by odinsdream at 7:34 PM on February 17 [1 favorite]


Pretty sure most white LEDs are blue or violet (NGAN) with a phosphor (YAG) emitting white. My understanding is that in the past 10 years the phosphors have got pretty awesome, though.
posted by Alterscape at 8:52 PM on February 17


Every LED bulb I've bought or even seen at common hardware stores and Ikea are direct light coming from the LED junction, and perhaps routed through some optical media for diffusion

Look closely and you'll see that the encapsulation over the junction in a commercial lighting LED is pretty much always yellow when then LED is off. That colour is given to the encapsulation by the phosphor grains embedded in it. The encapsulation is translucent, so it looks like you've got a direct view of the chip when it's working, but at least some of the light rays hitting your eye have got there via a grain of phosphor along the way.

It's also very difficult to judge colour accurately when the source is both extremely bright and not very close to either end of the visible spectrum, because the brightness just overloads the retinal cells in much the same way as super bright sources overload the CCD sensor in a camera. This skews the ratios between the colour-component brightness values delivered to visual processing neurons further upstream. At very extreme brightnesses, all the light-sensitive cone cells can be overloaded to saturation regardless of what colour range they're most sensitive to under normal conditions, and upstream processing will interpret their equally-saturated outputs as white light.

Also, even though you will see a very strong blue peak in the spectrum you get by playing with a cheap white LED and a prism, that blueness tends to get swamped on direct viewing because what's coming from the phosphors is also very bright, and what you appear to be seeing is almost impossible to distinguish from a junction that is in fact emitting white light right from its centre.
posted by flabdablet at 10:20 PM on February 17 [1 favorite]


jamjam: that blue peak is actually the highest in the entire spectrum, whether it's a warm white bulb or not. And there are some problems with blue light. It's been known for years now that blue wavelengths are by far the most effective in resetting your circadian rhythms

For this reason, I have drifted toward having LED lights for the morning and low-power, dim incandescents for the evening.
posted by clawsoon at 7:04 AM on February 18


I assume but am not sure that the Color Rendering Index (CRI) of a bulb relates to how incandescent-y and even the light spectrum is on an LED bulb. Higher would be closer to “normal”, with fewer weird LED specific-frequency artifacts.
posted by Huffy Puffy at 9:14 AM on February 18 [1 favorite]


Yeah, incandescents have a CRI of 100 because they are black-body emitters so that's how they roll. Better LED bulbs have CRIs in the mid-90s, but good luck finding one where the manufacturer is brave enough to actually list the CRI rating, they're like hen's teeth.
posted by Anticipation Of A New Lover's Arrival, The at 12:19 PM on February 18


The violet LED-driven bulbs I linked to above claim a CRI of 95.
posted by jamjam at 2:46 PM on February 18


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