Does anyone know of LED bulbs with a good dimming range? I really like my Cree bulbs, but their dim range is terrible. With my automation system, an incandescent light set to 1 (out of 100) is barely visible and truly one step from being effectively off. A Cree bulb at 1, however, is more like an incandescent at 30% brightness or more.

It's been interesting reading about how LED bulbs have to handle dimming digitally through circuitry, but that means it's up to the bulb.

So does anyone know of a bulb that can dim more?

The problem, as I understand it, is that you can't "dim" an LED. You have to use PWM, which means that the LED is on for a bit and then off for a bit, and so on.

If you "dim" it too much, the flickering becomes visible to the naked eye, and that gets really annoying. So, yeah, maybe there are LED bulbs that will dim further, but you're never going to get as dim as an incandescent.

Have you tried one of the newer LED filament style bulbs? A smart bulb might allow lower ranges as well, but you'll have to dim it with a home automation controller instead of a manual switch.

There is a fundamental awfulness to the old school methods for 'remote control' of lighting based on messing with the AC waveform being fed to the light 'bulb'. This was all we had for many decades dating back to lighting control in theatres using Variacs or potentiometers,

The electronic Triac based AC 'dimmers' worked well enough with incandescent filament bulbs by chopping portions of the AC waveform away, reducing the average power delivered to the hot filament. Sometimes there was visible flicker or shimmer but mostly this worked well enough.

Then the arrival of 'transformer' powered 12 volt Halogen complicated things as the Triac devices fought with the magnetic transformers. This begat 'magnetic' compatible dimmers. Then came 'electronic' transformers and yet again fancier dimmers to manage the hacked up AC waveform in a manner that the downstream electronics could cope with. Not perfect with flickering, incomplete dimming and delayed starting being fairly common issues. CFL lamps have similar issues.

LED lighting can be so low power that it messes with the basic premise of inline Triac dimming where the dimmer itself leeches power from the current flow to the load. When the lighting becomes very low power the dimmer often cannot sustain itself without consuming a large percentage of the total power to the load. Result is incorrect dimming, flicker or other problems.

In my view the whole idea of managing lighting by messing with the electrical supply to the 'lamp' is no longer viable. The lamp itself needs to manage its own power levels and brightness and be able to accept remotely issued commands for changes in brightness. This is of course what is happening with 'smart' lights and lamps, but overall we are a long way away from widespread implementation of this approach.

Lighting is one of a few things where there is this idea that it is ok to corrupt the AC power waveform feeding the thing. We do not dim our TV or adjust the volume of the sound system by messing with the AC input.

It will be a bumpy road from where we are currently with household AC wiring to reach an intelligently configured future where the power provided to all devices is clean and uncorrupted, including those devices providing lighting.

I had not realized that the US electrical code had been changed to require AC neutral conductor in new construction switch boxes, since 2011. This will allow for more stable operation of the dimmer controller itself but does not address the underlying problem of bizarre and potentially incompatible waveforms being delivered to the downstream lighting devices. Not to mention the undesired results from inadvertently 'dimming' a non-lighting device such as a TV.

I agree with everything you guys have said. I hadn't thought about smart LED bulbs being able to dim further but that makes a lot of sense. I'll have to look into whether any of them are supported by my system.


Ugh, don't get me started. Again, this is an issue I've had to warn new home automation users about. For some reason I keep coming across people who want to automate a lamp plugged into a switched outlet, and they decide to use a dimmer switch to do this. Yes, it'll technically work...for that lamp. But you won't want anything else plugged into it and that's too hard to predict.

Lutron makes a plug specifically for dimming lamps which I came across on amazon once and thought was an interesting idea.

My house is too old to have neutrals in any of the boxes, so I'm stuck with the older style dimmer with very few choices for zwave switches. They make every LED bulb purchase an adventure.

So it is against the rules entirely to allow dimming control of a standard outlet. Only allowed with special outlets and special lamp plugs.

That would imply that you cannot legally provide dimming controls to regular outlets, regardless of whether your clients promise to not plug other things into that outlet. Liability ...

Grounds (green or bare wire, missing from really old wiring), not neutrals (white wire, always present for 110-125V outlets).

Cheers

I think he was talking about wall light switch boxes, not receptacle/outlet boxes. Often no neutral/white wire in switch boxes.

Oh no no, I wouldn't ever do this for a client. This is just when I'm chatting with automation newbies in online forums.

LED dimming is challenging. I have all sorts of LEDs in my house, in some situations even a small change like changing a bulb (like for like) can start lamps flickering, degree of dimmability is also variable.

Ours are all on trailing edge dimmer switches, we didn't go for any fancy controls. The least hassle/most reliable have been the LED tape connected to driver that we've used for "wall washing".

Is that LED 'driver' module rated for dimming?

Many LED strip 'electronic transformers' are simply regulated output 12 or 24 volt DC power supplies, sometimes simply repurposed from generic laptop or other 12 volt power packs. Not rated or intended for any sort of AC dimmer control.

In my opinion LED strip lighting should be dimmed and controlled on the DC side, not the AC feed.

I have a very basic understanding of electronics, I assume that the driver is dimmable as it does indeed dim the tape, but I have no idea what's actually in there.

On a related tangent.. We installed a basic home-centre style range hood over the gas range in our kitchen. For the first few months it used just a regular pair of PAR20 halogen bulbs for the built-in lighting.

The unit has a three-step electronic dimmer circuit for the lighting, plus "off".

After a while, we got around to trialing LED PAR20 bulbs in the same unit, carefully monitoring to see if the plastic bulbs suffered from the stovetop heat. So far so good on that front, but..

Wandering to the kitchen for a midnight glass of water, I noticed the fixture was "on", though quite dim. Turns out, it is like that all of the time when supposedly "off". There is some leakage current always flowing, never enough to illuminate the halogen bulbs, but sufficient to light up the LEDs (dimly).

So that got fixed pronto, by hardwiring a new switch into the fixture to turn it completely 100% off, electronics and all. Such a senseless waste of power.

Cheers

I have yet to find an over the stovetop vent hood that is actually excellent. Even if the lighting control was well done, the fan noise is probably an order of magnitude louder than desirable.

Three speeds; Loud, louder, and at the loudest setting modest actual airflow.

My last house I removed the built-in noisy fan from the range hood housing (it was marketed as a high end quiet model) and instead ducted it to a attic mounted Fantech exhaust fan. Routed through a Fantech inline silencer unit (rated for kitchen exhaust) between fan and range hood (with a length of flex ducting to limit vibration transmission). Fan exhaust was through the roof with a weather shroud, but could also have been eave vented.

The result was circa 600CFM exhaust flow yet one could speak in normal tones while standing right in front of the cooktop, with the fan on high.

Excellent air flow and visitors standing in the kitchen often were not aware the fan was running, let alone on high.

I forget whether I used the 8XL or 10XL inline fan for that install. Worked very well and I would do something similar again. Buy the range hood for the aesthetics and lighting, bin the supplied fan and remote mount a 'real' exhaust fan.

We have a Berbel, it was expensive but it's the quietest and most effective hood that I've seen, it has non dimmable LED lights. Very easy to degrease too.

Interesting that the spec for sound levels is given for 'stage 3' while the fan speed range goes to 4.

I didn't see any mentions of noise or sound levels in the product descriptive texts, only within the tech specs tab.

Zero-based indexing problem?

Sorry, work eats my brain sometimes.

My guess is they don't want to publicly admit how loud the exhaust fan actually is on maximum speed so they selected a slower speed for the noise measurement.

We have a Blockline 120cm, it has 3 speed settings, compared to Gaggenau/Neff etc hoods that I've seen in other peoples houses this is noticeably quieter.

Just a small update: I actually ordered a ZWave LED bulb (because my whole network is ZWave) and well, it's probably a tiny bit worse. I'm guessing this is a bulb-by-bulb issue, so I don't know if a Hue bulb can get darker. I wouldn't be surprised, since it's probably a little better made than this one.

For now, I'm going to put a 40W bulb in the "nigh light" lamp and dim it to an extremely low level. It won't be quite as low energy usage, but it'll be close. I'm basically trying to ween my son off of a night light completely, so I need to be able to go reeeeally low, and LED's just can't do it, it seems.

LED bulbs can be covered with a coating or fabric that absorbs some of the light output. Just don't clog any air venting or cooling fins. You could experiment with draping or wrapping the bulb to reduce the effective light output.

Don't do this with incandescent bulbs, of course.

The theatre lighting world used to use neutral gray and colored filter gels all the time, I imagine that sort of thing is still available.

Other Industries also have similar films. You can layer the films to multiply the light reduction.

http://www.solargraphicshome.com/Neutral_Density_Film.html

This video shows the sheet neutral gray filter material, 1:58 mark.

One "solution" to getting a dim LED bulb might sourcing an older one. The newest are quite bright. Anything more than a few years old? Not so much.

That would dim all light levels, though, so I couldn't get the bulb as bright as I might want.

I think I'll go incandescent until I don't need the light at all.

You could use some other lamp for 'bright' and the cloaked lamp for 'very dim'.

Nah, that's not what I'm about. The whole reason I got into home automation is because I really love to have even lighting throughout a room. So I spread the light sources to logical and appealing spots, then set them all to the optimum dim levels for whatever scene I'm creating. My least favorite way to light a room is to have a single lamp in one corner that's turned bright enough to do something in the opposite corner, as that lamp will be too bright at its source.

So that would mean that to accomplish your suggestion I would have to have two lamps in the same spot. I guess I could also have a lamp with two ZWave bulbs in it, one of them "cloaked." But then I wouldn't be able to use the super cute monkey lamp that we currently use as his night light

I think I'll stick with the 40W. It's not going to suck too much juice. Not at these levels.

I've gone back to the 40W bulb and it works so much better. I can set the dim level to anything, and it performs beautifully.

Now I have two more questions for you kind folks:

1- What's with the buzzing? So many of my light fixtures let off this buzzing noise that seems much more pronounced with the LED lights in them. What's going on here? It's not as bad when the light is at full brightness, but when it's dimmed it's really bad.

2- Does anyone else dislike the color temperature of a dimmed LED bulb? I feel so set in my ways, but I guess my brain just likes the additional warmth of a dimmed incandescent bulb. It looks like LED bulb manufacturers know this, and I've seen at least one Cree bulb that claims to offer that behavior. Anyone else feel this way?

That's why I hate everything but incandescent lights. Fluorescent and LED all buzz because they need some kind of transformer. Those kinds of lights can't accept the AC current as-is, it's gotta be changed somehow, either to a DC current or to some other variant of AC current. What you're hearing is the transformer. Usually a cheap-ass crappy one, because good transformers cost more than people usually expect to pay for a light bulb. Whereas incandescent lights don't need any change at all, they just take the AC directly off the wire.

Some of the more expensive LED and incandescent lights might start their life buzz-free but then develop a buzz later on as they get older and the transformers age.

In my home studio, noise floor is everything, and I can't abide fluorescent or LED lights of any kind. (Or dimmers of any kind, which often induce their own buzz, either audibly or injected into the house current so that it shows up in the audio recording). What I don't understand is what audio recording studios (including my own) are going to do in the future when incandescent bulbs no longer exist.

Maybe candles?

Thanks Tony. That makes sense. I wonder, then, why the incandescent bulbs in my bathroom vanity also make that buzzing sound. They are also dimmed, but the buzzing comes from the fixtures and not from the switch. Is that still the dimmer producing that buzz?

If that's so, I wonder why all sorts of combinations in the rest of my house don't have this problem. I have LEDs and incandescents on dimmers and lamp modules elsewhere and they don't make this noise...