Stepping back (temporarily) from LEDs

Submitted by Andrea on May 8, 2012

Ted and I were all set to install LED strip lights, as described in my recent post about choosing LED lights. But then we spoke with my father's friend John—a major techie at a major technical manufacturing company—and he suggested we wait a bit longer.

He said that for the next two years or so, the best LED products will be Edison-style replacement bulbs that use remote-phosphor technology. LEDs do not produce a wide spectrum of light on their own, but when LED light strikes a phosphor, the phosphor emits a wider range of colors. You can see this in the Philips LED replacement lamps: the unlit bulbs look yellow, but the light that comes off them is a nice warm white.

Those kind of replacement lamps are the best short-term approach, but the longer-term approach will be multi-string ("but not RGB"). He said, "They will be phosphor-shifted blue LEDs picking up green-yellow (called BSY), with some combination of red/orange/amber LEDs at the longer wavelengths."

He added, "CRI is only a start at analyzing the problem. It's very outmoded, made a lot more sense in 1950 than today. Doesn't measure reds well (which are very important to human perception), and the spectral absorption are too broad-band." This confirmed our experience of CRI — the lights we were going to buy had a good CRI (85) but was noticeably weak in the red part of the spectrum. Ted looked OK under our test lights, since he has fairly rosy cheeks to begin with, but they made me look a bit more wan than usual.

Our informant likes two lighting models right now:

  • CREE LR6 (BSY/orange two string) — "This dims well, but the color changes a lot"
  • Philips remote phosphor A19 bulbs (the ones that look yellow when off), remote phosphor with Europium-doped YAG (gets good red rendition)

One thing he likes about these models is that neither has 120Hz ripple, admitting that not everyone is sensitive to this, but that it drives him nuts. He also notes that efficacy is approaching 100 lumens per watt, "which is a good benchmark for a warm white bulb."

He suggested we wait at least a year before installing LED strip lights for the following reasons (direct quotes):

  • The models that you're looking at don't actually use DC, but rectified high frequency AC that tracks the input line (120Hz modulated 25kHz). This means a lot of flicker.
  • They are also are "local phosphor single string", which means bad color.
  • The efficacy with transformer is probably about 50 lumens/W, not awful, but not good either.

Our new plan is therefore to postpone installing the strip lighting, but to leave all the rough wiring in place. We'll make do with floor and table lamps for a year or so and then install strip lights once they've improved the color rendering and efficacy.

I told him that most of the light fixtures we're buying take regular A19 lamps (Edison standard), but a few will take B10 lamps (Edison candelabra bulbs). He warned that it's harder to make good replacement lamps for smaller bulbs because there's not enough mechanical volume to make a good LED ballast. I asked whether CFLs at that size are any good, and he said, "Most of the fluorescent at that size are CCFLs, which have good life, but won't dim well, and have lower efficacy than larger CFLs. There's a effect called cathode drop which fundamentally decreases the efficacy of these small lamps."

He concluded, "Maybe this gives you something to think about. A lot is going to change in the next few years."

So you want to use LED lights...

Submitted by Andrea on March 23, 2012
Addendum: We got more advice and decided to wait on installing LED strip lights. Read more in "Stepping back temporarily from LEDs" (May 9, 2012).

I could not have designed and built this house without our good friend Google. I created all of the 3-D drawings in the free version of SketchUp, and I researched literally every component of this house using Google's indispensable search engine.

Unfortunately Google is nearly useless for researching items that are aggressively marketed online, particularly LED lights. The problem is that discount LED vendors use every trick in the book to rank among the top Google search results, so it's nearly impossible to find helpful online advice about how to buy LED strip lights.

Until recently I had only a dim (ha!) idea of what components we'd need for LED strip lighting. But now that we've figured it all out and completed our lighting schedule, I'd like to share what I've learned about illuminating a room primarily with LEDs.

Not all LED lights are created equal

I do not usually use all-caps (the Internet equivalent of screaming), but this is hugely important. It is tempting to order LEDs online from discount vendors, and you might know people who like the lights they purchased that way. Ted and I have some friends in Austin who purchased a lot of accent lighting from Eco Light LED, and the lights look really cool. Installed inside bookcases and behind valances, they have RGB controllers and can be adjusted to display a huge range of fun colors. Ted and I assumed we'd light our house with something similar, only on a larger scale.

We subsequently learned, however, that you can only get away with cheap LEDs if you aren't using them as a primary lighting source. When you look at a person, you're seeing the light that's bouncing off of them; the surface of their clothing, skin, etc., absorbs certain parts of the spectrum and reflects the rest back out. So if your light source is missing crucial colors, that person will look downright creepy.

Any decent LED manufacturer will publish the product's Color Rendering Index (CRI). This is an adequate (though incomplete) measure of the light's color fidelity. CRI is measured on a scale from 1-100, with ordinary incandescent lights at 100 and everything else somewhere below that. For your primary indoor lighting source, you shouldn't go below a CRI of 80.

Color temperature is also important, and it is easily misunderstood. "Warm" light actually has a lower temperature — incandescent bulbs are 2,700K and those blue-white LED xmas lights are around 6,000K (compact fluorescent bulbs usually range from 2,700 to 3,500K). All of our LED lights will have a color temperature around 3,000K and a CRI in the mid-80s.

Once you know a little about CRI and color temperature, the discount LED vendors no longer look so good. Eco Light sells Warm White LED Strip Lights for about one-quarter the price of the strip lights we're buying, but a closer look at their downloadable spec sheet reveals that the color temp is a not-so-warm 3,500K, and they don't mention CRI at all. I found CRI info on a few other discount sites, but the numbers were unacceptably low (70-75).

Most of our LED strips will be installed behind a valance, with the light shining upwards across the ceiling (the sole exception is the under-cabinet lights in the kitchen). The LEDs we selected have a good overall CRI (85) but are a little weak in the red part of the spectrum, which means we need to choose ceiling paint with a hint of red pigment so it won't absorb all the red coming from the LEDs. Our lighting consultant told us a cautionary tale about how indirect non-incandescent light bouncing off cream-colored walls can turn everything yellow, and we don't want that to happen to us. In fact, we had planned on using pigmented plaster for our walls, rather than the usual paint over drywall, but the lack of fine-grained color control pushed us back to the standard approach.

LED strip lighting basics

The first thing to know about LED strip lights is that they run at a much lower voltage than most other electric devices in your house. In North America, we use 120 volts AC (alternating current), and most LED strip lights run at either 12 or 24 volts DC (direct current). You will therefore need a transformer to convert from line voltage (120V) to the voltage of your LED system.

In case you're rusty on how electricity works, I should point out that the voltage has nothing to do with how much energy the lights draw. Voltage is analogous to water pressure (not the total amount of energy used), so the important number is how many watts a fixture requires.

Each circuit of strip lighting will require its own transformer (by "circuit" I mean a strip that's controlled by its own switch), and the total wattage of the strip lights cannot exceed the maximum output of the transformer. Our strip lighting draws 3W per foot and our longest stretch on a single circuit is 14'-4" (the upstairs hallway), which means our heaviest circuit will only draw 43W. The smaller WAC Lighting transformer is rated up to 60W, so we'll be well within the limit.

In case you're curious, here's what you'd need to run 14'-4" of strip lighting:

  • Two 2-inch LED strip lights
  • Four 1-foot LED strip lights
  • Two 5-foot LED strip lights
  • One 12-foot lead wire (connects the light strips to the remote transformer)
  • One end cap
  • One remote transformer (driver). Converts from 120V (line voltage) to the 24V required by the lights.
  • One dimmer switch for an electronic low-voltage fixture

Each segment of strip lights connects to the next, and the end cap terminates the string.

Incidentally, the reason we're fiddling with the 2-inch segments instead of just trimming a 1-foot segment (the lights are trimmable every three inches) is that it's marginally less expensive. This will give us the exact length we need.

Why bother with LEDs?

I confess that writing this post has made me wonder why we're installing LED strips when CFLs use roughly the same amount of power. People criticize fluorescent bulbs (compact and otherwise) for containing mercury, but it's just a tiny amount and can be recovered if the bulb is properly recycled. LEDs don't contain mercury, but various toxic chemicals are used during production, and their heat sinks are made from valuable metals like aluminum.

So why are we using LEDs? I suppose it's partly the eco-bling factor. But we're installing plenty of conventional fixtures too, and in the short run we'll probably fit most of them with CFLs. LED replacement bulbs tend to shine in a single direction; this makes them a good choice for recessed downlights, but not so good for wall sconces and multidirectional fixtures.

We considered using a series of T5 fluorescent tubes for all the indirect lighting, but then we'd run into "socket gap" — dark spots where two bulbs meet. We would also have to build a larger valance to hide the bulbs, and there are a few places where we need to keep the valance quite small.

We therefore succumbed to the blingy lure of LEDs, and I sincerely hope they'll earn their keep during their projected 50,000-hour lifespan. That's 17 years, assuming we run them eight hours a day, which I doubt we'll do. Again, this is why it's important to choose the manufacturer carefully, since we're likely to be stuck with these things for a long long time.

I keep thinking I can cover lighting in a single post, but each time I try I wind up having too much to say. In a future post I'll share diagrams and photos of our indirect lighting setups. I'd also like to talk a little about switches (whee!), and now that my eyes have been opened to the subtle art of lighting design you can expect a rant or two about bad lighting.

Added on May 9, 2012: We changed our minds. See "Stepping back temporarily from LEDs" for the details.

The deep dark world of lighting

Submitted by Andrea on March 12, 2012

After struggling for months to complete our lighting plan, I now understand why most builders just give up and install recessed cans everywhere. You put a decorative fixture over the dining room table and in the bedrooms, maybe combined with a ceiling fan, plus some attractive pendants in the master bathroom, and voilà — a lighting plan!

Ted and I stubbornly resisted this approach, and after wrestling for ages with our own lighting design I can absolutely see why most people succumb and go the easy route. Our not-so-fun experiences included:

  • Getting a terrifyingly-high initial quote from a top-tier lighting consultant (more on this later).
  • Spending countless hours perusing lighting websites (I'm looking at you, Lighting Universe,, LampsPlus, Rejuvenation, Schoolhouse Electric, Barn Light Electric, Neena's, Lightology, and
  • Being led down the garden path by a vendor who said we simply had to see their terrific showroom, and then driving a long way to discover they had a tiny showroom with exactly nothing we liked.
  • Asking for specific advice from said vendor, waiting a week for that advice, but then being sent nothing but a quote for hugely expensive fixtures we never even asked about.
  • Choosing a bunch of attractive and reasonably-priced pendant fixtures, only to find out that someone near and dear to us suffers petit mal episodes around gently-swaying pendulums.

Yup, putting together this lighting plan has been a non-stop party! But now that the plan is done, I'm glad we toughed it out — I think our lighting will look great and function well, and I want to share what we've learned.

Our first step back in October was to contact a highly-recommended lighting designer from out of state. We got off on the wrong foot, though, when he sent us a quote based on a palatial Vermont ski house he had consulted on, and we had to explain that we were the lesser-known kind of of Vermonter who only has one home. (The overwhelming majority of Vermonters fall into this category, but if you're a renowned lighting designer in the greater NYC area you tend to meet only the other type.)

Once we conveyed to him what cheapskates we are, he assured us that he's happy to work on an hourly basis for people who just want a few pointers. Our first meeting with him was very productive and we planned to keep consulting him, but then Ted broke his collarbone and I freaked out about costs and decided we should just figure out the lighting all by ourselves. Ted devised an elaborate plan, rife with LED strips and T5 fluorescent tubes hiding behind valences, but it was really way too complicated and when I presented it our electrician in late January he soberly told us it was going to cost a friggin fortune to install.

We weren't really sure how to proceed, so we decided to meet with the lighting consultant again. He took a red pen to our plan, and two hours later we were all set. Here are the key items:

Indirect LED strips

We're probably going to get WAC Lighting InvisiLED Pro strip lights. They have a pretty decent color-rendering index (CRI), though a little short on red, which means we need to be careful when we choose our wall paint color. The light will bounce off the paint, so we'll go with a faintly rosy shade of white.

More recessed cans than I expected

Our lighting bible has been Martin Holladay's 10 Rules of Lighting, and he really hates recessed downlights. He points out that in nature the sky is bright and the earth is dark, and yet downlights mostly just light the floor. Furthermore, they cast unflattering shadows (as my bathroom mirror reminds me every morning), and on a high ceiling they don't really provide much useful light at all.

Ted and I were prepared to forgo recessed cans almost entirely, using them only above the shower and bathtub, and also as tasks light over the kitchen sink. But it turns out they work well if placed the right distance from the wall (24-27" for a high ceiling), and so we're going to use a wee smattering of them. They'll all be Juno IC-20 5" housings, with LED PAR30 replacement lamps.

Lighting alongside the bathroom mirrors

The most flattering lights for a bathroom mirror are the old Hollywood-style lightbulb surround. Light hits the subject from all directions, which means no creepy shadows. But many bathrooms only have downlights (this kind of fixture is all too common) — they look nice on the wall, but not so nice on the face.

The Hollywood lights are a bit over the top (and screamingly inefficient), so we're going with sconces on either side of the mirror. Not fancy, but flattering, and it'll bounce some light off the ceiling as well.

(We found an awesomely goth lighted mirror that we wanted for the master bath, but sadly it is discontinued and we'll have to content ourselves with something far more pedestrian.)

Incandescent decorative fixtures

Wait, huh? I thought incandescent bulbs were a big waste of electricity!?

They are, but the fixtures have nice standard sockets which take plain old Edison bulbs, and that's the biggest segment of the LED replacement market. So as long as we choose decorative fixtures that don't take too weird of bulbs, we can easily make them more efficient.

Choosing fixtures was often quite a challenge. Ted and I don't always have the same taste, and we're both quite opinionated. And once we agreed on a fixture that was the right price (another huge challenge), we'd discover it uses some crazy little non-standard halogen bulb which will almost certainly never get an LED replacement.

No dark shades!

This also comes from Martin Holladay's lighting rules: Don't block that light with silly dark shades. And don't obstruct light from bouncing back toward the ceiling. We're being careful to prevent glare from exposed bulbs, but otherwise we're letting it all hang out, lightwise.

I could say much more on the topic of lighting but will instead treat you to photos of some of the fixtures we've picked out.

Wall sconces along the stairwell:

On either side of the master bathroom mirror:

Two rigid-stem (non-swaying) pendants over the dining room table, hanging off a monorail:

A big friendly pendant in the middle of the kitchen ceiling:

Wall sconces in one of the guest bedrooms:

A cheerful little ceiling light at the back door:

There are several others, but I will wait until I can display them in their new home!

Fun with light fixtures

Submitted by Andrea on September 17, 2011

My quest for attractive and inexpensive light fixtures has begun, and my old friend the Internet is ready to help. I have no intention of turning this website into an interior design blog, but I couldn't resist sharing my bright idea.

I quite like this light fixture, but I wouldn't dream of sullying our Almost Passive House with an egregiously incandescent bulb:

However, I think it would look smashing with a Plumen CFL, don't you think?

Yes, Plumen bulbs are pricey ($30 USD), but the fixture itself isn't too outrageous ($119), so I think this could work. Not sure where to put it, but I'm sure we'll come up with something.

Lighting: My nebulous plan

Submitted by Andrea on September 15, 2011

The time has come, the Walrus said, to start deciding on interior fixtures and finishes. I've been focusing for so long on things like the foundation and the building envelope that it feels weird to focus on mere fripperies, but I can put it off no longer. Admittedly, I picked out my kitchen faucet years ago (I installed the same one in two previous houses), but I'm in a fog when it comes to interior lighting.

Ted had the clever idea to use LED strip lighting to give rooms the ambiance of a dorm room lit by Christmas lights. It's a soft, friendly sort of light, which is all we'll need when we're using our laptops (i.e. 90% of waking hours). Furthermore, we could use RGB controllers to change the light color, which would look pretty darn excellent. And of course we'd have some bright overhead fixtures for times we want to actually see things and not just pass the bong around. (I'm speaking figuratively, not literally — Ted and I are utterly and perhaps boringly substance-free.) LED lighting: Energy-efficient and mighty slick.

Alas, I've found no examples online of what we want to accomplish. I've found a lot of McMansiony-looking LED cove lighting, which is not our style at all. I'm imagining LED strips tucked behind curved moldings but not so close to the ceiling. Ideally it would bathe the wall in weird indirect light and look really cool.

But I have no idea if this would work. I suspect you need something above the LED strips to reflect the light back down. Furthermore, there are heaps of LED vendors online but I've heard there's a lot of junk out there. So today I called a lighting consultant recommended by Eli to see if he can help me navigate this bright glowing sea.

We spoke briefly on the phone and he warned me that LEDs are currently more expensive than conventional lighting (sigh). He confirmed that most of the LEDs available online are crap (and no, he doesn't sell anything himself — he just provides recommendations). We'll probably set up a meeting with him to discuss our wild notions and to see if we're heading in the right direction.

As for the overhead bright lights, I think we'll use a combination of LED recessed lighting and hanging fixtures fitted with GU24 sockets [ETA: Or not — see below.]. That is, if someone doesn't convince me that GU24s are a flash in the pan (ha!) and that this recent article about GU24 lighting from Green Building Advisor is all wet.

I have a sinking feeling that LEDs are not quite ready for prime time, which is frustrating because they surely will be within a few years. And of course they use a mere squeak of power compared to incandescents, and they are less flickery and annoying than CFLs.

Words of lighting wisdom are welcome!

[Added on 2011-09-18:  Erik Haugsjaa emphatically pointed out that GU24s are best suited for landlords or developers who want to force residents to use energy-efficient bulbs and that they're actually a terrible choice for us, given the lack of fixtures available. So we'll go with good old Edison overhead fixtures instead.]