Do you save energy using occupancy sensors with LED lights?

Factual Questions
1

So, I’ve decided to finally upgrade the rest of the house to LED, now that there are the $2.50 Phillips bulbs as well as inexpensive high CRI bulbs that are supposed to solve any spectral problems. (I plan to use a mix, the phillips will go into multi-bulb fixtures as well as a high CRI bulb or 2, as well as outdoor and garage lights I rarely use)

So, these new bulbs eat around 8-13 watts, depending on the bulb and the type. Occupancy sensors also eat power to run their motion detector. So if it eats half a watt all the time, and this saves me from a certain amount of hours per day of eating 8 watts, it doesn’t sound like I get ahead by much.

Maybe I could wire the switch in the kitchen, living room, etc as an occupancy sensor and the switch in rarely used rooms as a vacancy sensor? (so it doesn’t consume power running the motion detector once off, I hope?)

I guess from another perspective, once you have LEDs, occupancy sensors are probably a waste of money. The sensors are about $17 each on Amazon for the brand with good reviews. If the sensor saves you 12 hours a day for a 4 bulb circuit that consumes a total of 48 watts, then it saves me…$23 a year. Wow. Still worth it. Even if the thing *does *have idle power draw, it’s worth it.

And while the sensor costs money and has idle power draw, it also costs money every time you forget to turn a light off, or if you trip over something because a room is too dark…

2

LEDs don’t use that much less than CFLs, but instead of lasting years, their life span is (supposed to be) closer to a decade or two, that’s where the savings is. If people in your house have an issue with leaving lights on, adding occupancy sensors will be nice, help with the longevity of the bulbs (and all the heat they produce) and it will save money. If not, I wouldn’t bother, unless you just want them for the wow factor, that’s different.

3

I don’t know if occupancy sensors will do the same thing, but I noticed something strange when I put in an LED bulb in the garage. It glowed all the time. Not full brightness, but enough that you could see. The wall switch that controls the bulb is one that glows a little. I’m guessing that it leaves enough ‘juice’ go to the light.

Come to think about it, I have LED bulbs in the motion sensor light in our back yard. They don’t glow when ‘off’. I’d assume that occupancy lights are similar to it.

4

This is a common problem with LED bulbs. Fancy switches that require a small amount of power will draw just enough to cause the LED to glow, but not enough to light up an incandescent filament. Current electrical codes always require a neutral in the switch box so fancy switch devices do not energize the switched circuit when it’s supposed to be off, but if it’s an older house with switch-loops then you can run into that problem.

5

I have a set of three vanity-shaped, low-luminance (like 20 W equivalent, I think) LEDs. These glowed very slightly in my previous apartment’s bathroom, with the (completely unremarkable, non-glowing) switch off. They don’t glow at all with the switch off in my current apartment’s bathroom. Since the switch in the old apartment wasn’t anything special, I don’t know why there was some electricity finding its way to the LEDs.

6

An interesting issue I have is that in one room I have LEDs, in the next room over (different circuit I think), I have fairly early CFLs (probably had them close to 10 years). Anytime someone turns the lights on or off in that room, the LEDs in the other room flick. It’s annoying if someone is playing with them.
I’m not sure if the CFLs or the LEDs are the problem, it could even be the dimmer the (dimmable) LEDs are connected too. It’s not that big of a deal so I’m not really that concerned about it.

7

Once high-quality LED bulbs become cheap and plentiful, what am I going to do with my lifetime supply of incandescents?

8

You can use them in closets and the basement and garage and other places where the light is only on for a few minutes here and there. But what did a lifetime supply cost? Incandescents are, what, like a $1? Toss them if you don’t have any use for them.
Or, just keep using them in all your regular spots, they only last a year or two. But going from 60 watts to 10Watt is probably worth just sacrifice.

9

Take up a hobby where you can use them as space heaters? It’s always what they were best at, anyway.

10

I just replaced even the closet bulbs with those $2.50 Phillips LED bulbs. I bought more expensive Feit Electric high CRI bulbs (they are the cheapest bulbs that offer a CRI rating over 90) and I have installed them in important places in the house where I think light quality is important (my bedroom, the office, the kitchen)

My reasoning is at $2.50 for the phillips, if I forget and leave a closet bulb on for a long enough time-period, it’ll cost me more in electricity than the Phillips bulb costs. Also, closet bulbs tend to burn out at inopportune times, and LEDs, even cheap LEDs like the cheap $2.50 ones, inherently have many times more longevity. (I suspect the average phillips bulb will last at least 5000 hours compared to 1000 for an incandescent.

11

Put them on fleabay. No doubt there are plenty of anti-vaxers etc who are never going to switch to these new fangled LED things on the grounds that they are clearly a Government plot.

Come to think of it - hang on to them as they will probably increase in value.

12

You could package them with old seeds, a commemorative gold coin, and a bride and groom wedding topper and sell it as an emergency modernity prevention package. $$$

13

I’d take them.

I just tried some LEDs for the very first time. These were Philips 100W equivalent. I bought two, one 2700K and one 5000K. They didn’t seem to be available in the intermediate 3600K-ish temp I really wanted. These are traditional A (pear-shaped) globes, but with the bottom half as the electronics package so the light only comes out of the top hemisphere.

Total abject fail, even in a simple non-dimmed pole lamp = torchiere. The perceived quantity of light was less than a well-used 60W incandescent in the same fixture. And the light was emitted only upwards from the hemisphere, whereas the goal in a pole lamp (indeed almost any lamp not set in a ceiling can) is to have light coming downwards as well.

The 5000K lamp put out a harsh blue light that was painful to look at even through the frosted glass fixture envelope. It made cheap 1960s shop light fluorescent tubes look nice. I stay in a lot of hotel rooms and put up with a lot of uber-cheap Chinese CFLs. This had obviously worse light quality than those.

The 2700K one seemed to put out even less light, but it was a bright orange and qualitatively very different from incandescents at either full or partly-dimmed voltage.

Neither bulb put out light my eyes could use to read by.

I’ve been back twice trying to find bulbs of any shape or wattage at the intermediate color temp to complete the experiment. No dice. Admittedly I haven’t visited other big boxes or dedicated lighting stores, but there don’t happen to be such in a convenient location. Maybe this weekend …

The good news is they cost $10 each at my local big box. Color me exceedingly disappointed and therefore skeptical. I believe in progress, but if this swill is what the mainstream public accepts as “good lighting”, I’m gonna be searching eBay for contraband incandescents before too much longer.

14

My objection to things like LED status lights is that most houses end up filled with them, and even when you want darkness you get this perpetual multicolored glowwwww everywhere. I started an effort a few years ago I tagged the “glow to hell” project - with the aim of eliminating, dimming or darkening all status lights, panel backlights etc.

There are times I want to sit in my living room or family room without feeling like I’m James T. Kirk, y’know?

15

LSLGuy, you drive a vehicle that uses state of the art technology as well as some conservative bits through the airlanes of the sky. Don’t be a luddite. Your problem is not that LED are inferior, your problem is you bought the wrong ones.

Well…it’s a failure of government as well. The bulbs you bought are not eligible for utility rebates, California will not give you a discount…because they are shit and the regulators know it.

The key factor or statistic you ignored is color rendering index.

You can look up exactly how they calculate it, but essentially, for a light at a given intensity, 8 standardized color samples need to reflect light at a given resulting intensity using a standardized testing apparatus.

A plot is produced, and a score is calculated somehow, I don’t know if the errors are linear or quadratic. In any case, it needs to match to the old school incandescents. If it does match, and it doesn’t flicker or buzz or fail and is bright enough, it will perform the same in the field. (except it will burn less than 1/8 the energy and last 20 times longer)

In short, if the CRI matches(above 90), and the color temperature matches (you want only 2700K or 3000K, nothing higher, if you are trying to mimic incandescents), and it fits in the socket, and the bulb is bright enough, and it lasts long enough, you have chosen a good LED.

Feit electric seems to make the cheapest ones that match all the above. Green Creative, Cree, and Phillips are probably more reputable brands but I voted with my wallet since failures are probably low enough that it is more efficient to get a cheaper brand that fails slightly more often and replace the broken ones.

16

Internet. I was just at a big box yesterday, having done my research. I picked up the crappy $2.50 Phillips, they are $2700K. These are used in locations that are not used to “read by”.

You want something like this, this, or this. See that sticker on the package? Some big box stores do carry a bulb like this, but you are probably going to need to buy it from the internet.

It’s like McDonalds versus Chipotle, or a 90s Volvo versus a 90s Ford Focus. The price premium between the mass market swill and the pretty solid, quality product is only 30% or so, but in the race to the bottom, people skimp on the 30% that can result in a huge gain in quality…

17

I bought some GE LED’s a year ago. They’re 11 watt, 800 lumen, 2700 k bulbs. They were initially $4.50 or close to that price. They’ve since doubled in price.

I have them in my ceiling fan and am extremely pleased with them. They have a softer shading at the top of the bulb which makes them ideal for fixtures pointing down. The light distribution is better than any other bulb type and they don’t blind you looking at them straight on.

The engineers responsible for them should get some kind of award. I’ve purchased other brands but haven’t tried them yet. We get CFL’s subsidized by our power company so it doesn’t make sense to buy LED’s for any fixture with a cover. At my age I may literally have a life time supply of the CFL’s in the pantry waiting to be used.

The only place I have a traditional incandescent bulb is in my garage. 2 of the 7 fixtures use them and their purpose is to come on immediately at full brightness. When 100w equivalent LED’s are $4 I’ll buy a couple.

As for light sensors I don’t really see the need. I turn lights on and off as needed. If I had kids who forget to turn them off then I’d just take it out of their allowance.

18

Use them in the winter when that extra heat is actually useful.

19

Even this is not true. Sure, the heat is better than nothing, but

  1. The heat tends to be at the ceiling and needs to be circulated by fans that are not present in a normal setup.

  2. Heat pumps have coefficients of performance for a modern one of about 3-4. That is, you get 3-4 joules of heat for every joule of electricity burned.

This does depend on what the outdoor temperature actually is. In my climate, the outdoor temperature virtually never goes below 32 fahrenheit, so the COP won’t go below 3, and will usually be closer to 4. If you live in Minnesota, it might go down to 2 pretty often…and 2 is still twice as good as using resistive heat.

20

Alton Brown style Mega Bake Oven?