Post date: Oct 22, 2014 2:37:26 AM
I know, it is not yet time to think about lighting - we don’t even have a fixed floor plan yet. But I seem to work on details first.
Walking through Home Depot I notice that LED is the latest fad - even in places where it doesn’t seem appropriate to me such as ambient lighting and linear applications. What is the big deal?
LED (today) and Fluorescent produce roughly the same amount of light per Watt of electricity. A 32-Watt T8 (8/8" diameter) tube with electronic ballast having Color Rendering Index (CRI) in the 80's and color temperature of 3500°K produces about 2950 lumens (depending on manufacturer) when new. That's 92 Lm/W.
A raw white LED (without power supply) can produce 5-150 lm/W. Screw-base lamp might produce 55-80 lm/W and a reflector lamp 60 lm/W.
[For reference, a typical tungsten filament incandescent bulb produces 15 lumens per Watt, and a low-voltage halogen about 24 lumens per Watt.]
But the big difference is that fluorescent tubes emit light radially while LED emits light in one direction from the face of the diode. That means that the configuration of the lamp and the fixture are very important. Fluorescent lamps come linear, folded, circular, and twisted. Thus a twisted CFL installed in a nearly flat ceiling fixture requires a reflector in the fixture to get more than half its light close to downward. A cleverly designed LED spot lamp can put most of its light into the spot without need for large reflectors. A LED type-A (pear-shape) lamp requires mounting the diodes in a cylinder, and then the usual fixture may waste much of this light.
For under-cabinet lighting, downward-facing LEDs put the light where it is needed, whereas a fluorescent tube shines half of its light upward into the fixture, which may be painted white (and is therefore somewhat reflective) but still wastes considerable light within the fixture.
Halogen puck lights are clearly not right, as they inherently shine in all directions (requiring individual reflectors) and get very hot. A fluorescent tube is the right shape (linear) for this application. A string of down-pointing LEDs is also good if they are placed close enough together.
But what about the cost of the fixtures. Right now LEDs are the latest fad, so the price of fixtures is higher. Fluorescent under-counter fixtures are passé, using common (read: inexpensive) designs and manufacturing processes. For example, a 22" fluorescent fixture may cost $22 emitting 600 lumens with color temperature 2700°K and CRI of 80. A comparable 24" LED fixture costs $150 emitting 525 lumens (close enough) with color temperature 3000°K. Another is priced at $105 but emits only 485 lumens at 2700K with CRI 85, or 66 lm/W. Or you can pay $190 for a 12 Watt dimmable unit that emits 600 lumens with similar color.
What do you get for your extra $100 (per 24" cabinet)? Longer life, certainly. Fluorescents claim lifespans of 20,000 to 30,000 hours. LED claim 20,000 to 100,000. Let's assume you use the lights 4 hours per day, 30,000 will last 20 years - probably longer than you will use this kitchen before a significant remodel. And it is certainly easier to change a fluorescent tube than a LED or LED fixture.
What about saving electricity? They both use about the same amount, so that is not a significant factor.
I vote for fluorescent.
Here there are a few major wall fixture styles:
Some of these may look ridiculous on the outside of a house that is supposed to look like it were made of adobe. And we cannot have any outdoor lights that shine upward.
So my thought is to specify a common-looking hanging box with no bottom, then install either an omnidirectional lamp (such as a twisted CFL) or a down-pointed flood lamp. This gives me a little flexibility in both light pattern and lamp technology.
I want some lights that are motion-sensitive, but don’t want the ugly spotlights that everyone uses. I want the same outdoor fixtures, just controlled. So I will mount the sensors where they pick up the right motion and the lights where they do the most good.
All outdoor lights should automatically extinguish during daylight.
For path lighting nothing beats the solar LED lights. Need to get the luminosity, as some are very dim.
Valance lighting (strips hidden behind a board) that are mounted above a window can - at night - imitate the nice light that you got through the window during the day.
I am rather fond of the white glass bowl stuck to the ceiling with a Circline fluorescent tube inside. Maybe with a little metal trim to match the fixture in the bathroom. Those tubes are perfectly suited to a round fixture, are very efficient, and come in a number of color temperatures and sizes. Sadly, they are rapidly going out of style. Their fixtures are generally quite plain, but nearly out of sight on the ceiling.
To light or highlight individual pieces of art work hung on the walls, I have the choice of track lights or recessed eyeball fixtures. The recessed fixtures are less obtrusive. The track lights are much more flexible.
I’d say the track is easier to install and the track heads are priced from under $15 to $670 (for blown glass pendants)
This is a situation where compact fluorescents are not technically the right solution because they radiate light in all directions. Here light-emitting diodes (LED) are the suitable source. A standard screw-in fixture is reasonable, too, because the base of the lamp is away from where you want the light. So cheap line-voltage fixtures with LED spot lamps is the way to go.
The price of LED lamps is dropping fast. I can get them from Hong Kong for under $5 each, although most sold in the US today are $25-30 each.
You don’t really want to light the room or the top of your head or the mirror. You want to light your face. Thus the only place for lights near the mirror is on both sides, at face height - above and below. Thus you need vertical strip lights. This is a clear case for an 18” or 24” fluorescent tube, but such fixtures are hard to find now.
Fluorescent tubes have been replaced by compact fluorescents and they simply install two in a long fixture. This is inherently more expensive and gives less uniform light in a linear fixture than using a fluorescent tube. But that is what is available. Sigh.