replacing CFLs with LEDs

Like many people, my wife prefers the warmer low K, but I like the higher K. I've long considered soft lighting wasteful and would buy clear incandescent instead of pearled even before I bought my first CFL.

I have 6 LED bulbs, all A19 replacements.
- Rear deck: 2 x 40Weq (8W?) daylight. CFLs can't handle cold well so outside lighting was the first target. Don't need them at Christmas when the LED tree's out there though.
- Downstairs bathroom: 11W daylight Home Depot. 850 lumens for instant on. Actually quite shocking when you're sleepy and you've been used to the gentle flickering of a just-turned-on CFL.
- Laundry/computer room: 11W daylight Home Depot 850 lumens. There's a dimmer switch and although we don't use it seems to make non-dimmable CFLs flaky in there. LED replaced a higher-wattage dimmable. The light seemed slightly dimmer than the higher wattage it replaced, yet somehow clearer at the same time. My wife doesn't complain (much) about the light.
- Lamp in the living room: 12.5W 2.7K Philips 800 lumens. They're occasionally available at our local Home Depot for less than $10 since they're an old model.
- I can't remember which room now: 12.5W Philips.
Note that Philips bulbs were updated to 11W/830, a significant improvement in lumens/Watt. LEDs keep improving and I'm hoping that higher-output bulbs will drop in price, as there's 3 20W warm CFLs over the bathroom mirror that I'd like to replace with LEDs when they blow.
I'm always very keen to get small intermediate LEDs to replace small 40W high-intensity bulbs under microwave. But that may be a few years.
I should also get an LED ready for when the fridge light blows. Or maybe I'll just wait until I need to replace the fridge-freezer. Newer models come with LED lighting.
Damn old houses.

 

I get the sense we're just beginning from different definitions of "good" lighting. To me, it's CRI very importantly, then the match of color temperature to the surroundings and to the purpose of using the space. I would borrow FL_Prius_Driver's idea about not letting numbers overshadow the reason for having nice room lighting in the first place. We can be thankful for living in a time that is rapidly expanding our options for efficiently lighting our spaces in ways that please us.

That said, in case anyone is reading who hasn't already seen graphics like the one you posted, it's worth pointing out that, first, what the color-temperature number refers to is really a blackbody spectral curve (nice images here), and about the only way to get a real blackbody curve is by heating up a real blackbody. Any image shown on a computer screen to illustrate color temperature differences is made by calculating the red/green/blue values according to the illustrator's choice of which color temperature to show as "white" (which then comes out as whatever color temperature your monitor approximates at maximum red/green/blue). Your graphic was chosen to white balance around 4500K so that it would illustrate the relative blueness and yellowness above and below, and it does that well. It just doesn't really capture the way our vision adjusts to consider many different spectra 'white' in different places and times of day, usually without our noticing (unless we are using something like an old camcorder with manual white balance, which will surprise us with how yellow or blue it thinks the scene is, until we tweak its white balance to match what our own vision came up with). It's more the contrast between different color temps that we really notice.

That reminds me that I had good, high-CRI 4100s in my basement for a few years and I was quite happy with them (yes, a partial retraction of my earlier teeth-on-edge comment). It's not a spectrum I'd choose for a living or dining room, but for the kinds of things I work on in the basement it's fine. I changed them after a few times I had driven down my street at night after forgetfully leaving the lights on. The light out of my neighbors' windows is still largely 2700ish, and my basement windows made an unattractive contrast, like I was running a small prison or morgue or something. I changed to equally-high-CRI 3000K in my basement and I'm just as happy being in the space, plus the effect from the curb is much nicer.

Another thing we've only kind of talked around is that since neither fluorescents nor LEDs can really produce a blackbody spectral curve, they fake it by mixing various specific color phosphors to get a mix that will look a certain way to human trichromat eyes. What colors to mix up to imitate an x Kelvin blackbody spectrum is Pop's secret recipe for each different brand, and those can be noticeably different even between high-CRI offerings. For example, the first 85 CRI 3000s I tried were GE or Sylvania (I forget) because a nearby store had them, and I found the color cloyingly pinkish, which is not the case with the Philips versions I have now (same Kelvin and CRI rating). It's not just me because my friend who changed out the 4100s in the kitchen did the same thing ... picked up the GE or Sylvania at the closest store, took them home, thought "whoa ... pink" and got the Philips (now easier to find since Home Depot stocks them).

The color-mix recipes that work for human trichromats to imitate various whites could look quite different to animals that have dichromat vision, or even other trichromatic animals whose cones are tuned to different wavelengths than ours (e.g. bees). Some humans are dichromats and it might be interesting to ask them how different fluorescents and LEDs look (I'd guess the manufacturers actually do this). Those birds, reptiles, etc. that outdo us by having more than three cone types probably think all our high-CRI CFLs and LEDs suck.

Color vision in other animal species

-Chap

 

I'm glad you brought those details up. Lighting is far too complicated to be reduced to one number. Some time ago I read where a small percentage of people have a slightly different eye opsin spectral sensitivity. It made their color sensitivities different from the vast majority. I'm always wondering how this would show up where so much color matching using discrete color components is matched for the majority, not them. (e.g. They cannot get their TV set to look "normal" to them without looking color skewed to someone else.)

 

Complicated topic, to be sure.
When we say that the lamp has a natural lighting, what time of day are we relating to ?

 

From the previous post, I would say "natural" has nothing to do with the time of day and instead refers to a total light spectrum profile that matches the sun for whatever time of day picked.

 

I may not be following you. The lamp presumably has a constant radiation spectrum profile, while sunlight changes throughout the day. Right ?

 

I never thought of that, so you might be onto something interesting.

However, all I was trying to convey was using the suns spectral profile as the basis of calling a light output natural. More specifically, any light source that puts out a single or series of narrow light frequencies instead of a continuous range of frequencies would not be called natural. Just to be overly technical, a TV set puts out only three or four narrow light frequencies to (successfully) fool our eyes into perceiving what the scene looks like naturally in real sunlight. So my definition is not tied to the temperature at all, but the spectral composition for the temperature picked.

That is certainly not the "marketing" meaning of natural, so I'm not insisting my definition has legs. It just has a clear match to what nature provides.

 

To muddle the topic a bit further, I wonder how many homes have over the years picked colors to best complement incandescent bulbs in the sense of what we humans tend to find pleasing. Perhaps fluorescents are fighting against a stacked deck.

 

An example I just remembered is that a few years ago I bought my sister a Samick Sage. I had it out of the box at the store admiring the nice rich browns of the wood just as you see in the brochure, put it back in the box, brought it home, took it out in my bedroom, and had one of those sanity-doubting moments: wait, didn't I have this one out in the store? Did they switch boxes? How did I not notice this wood is green? I mean, green green. Really, strikingly, they hadda stain this wood green on purpose green.

I didn't have time to take it back so I just shrugged and took it outside to try out a little, and as soon as I was standing outside I looked down and what I had in my hands was totally brown again, like it had never been green at all, and I thought aha, had me going for a sec but now I get it.

The CFL in my bedroom is a good quality, high CRI light that I've been very happy with and had really never noticed distorting any other colors before. It's just that whatever very specific red wavelengths reflected by that particular wood that make it not green are apparently not any of the reds coming out of my particular CFL.

-Chap

 

CFL 13w twist blubs at Costco $1 for 4..................

 

Or if they can even get it to look normal to them at all, if they're sensitive at wavelengths very different from those of the three TV primaries. Not that you can't compute a transform from one color space to another with different primaries, but in general some colors may transform to vectors with one or more negative values, which the TV isn't going to be able to reproduce (until they figure out how to build pixels containing LumiSuck™).

-Chap

 

Depends how the dimming is done. If the dimmer is just expending as heat the energy it does not send to the bulb then no energy savings from dimming.

I'll take a confident guess that the efficient (read:not wasteful) dimmers are more expensive and likely cannot recoup their extra cost. I do not bother with dimmers.

Re: subsidy, my local utility subsidizes CFL bulbs. Honestly though, at this point in the price curve CFLs are cheap, period.

 

The nice thing is you get to be judge, jury, and victim. (Just jesting). Let us know how it works out. I find reading with 3000K light comfortable. Much higher bulb temps are somewhat more distracting to me. When I'm home, I get to choose what works for me.....exactly like you are going to do.

 

... a deeper, more penetrative coefficient of extinction, several health related issues (e.g., postpartum depression; sleep deprivation) associated with blue light exposure, you are unequivocally better off with florescents or incandescents. Principle cost-benefit issue, putting LEDs outside is going to be, theft. The theft of just one LED bulb negates any gain, over and above incandescents -- asj.