28 June 2008

Lighting affects us more than anything in our home

Lighting is an art as much as a science. Lighting affects us more than any other detail in our home. Light conditions our emotional and physical comfort.

We need good lighting for our daily activities, to see clearly, to prevent fatigue, and to support our mood. We can light a room for a particular occasion or activity; we can change the usage of a space more quickly with light than with any other decoration detail. Lighting variations affect our daily rhythms giving us either a comfortable or a miserable mood.

Besides allowing us to see, lighting sets the emotional atmosphere. Understanding the effects of lighting is a key parameter when selecting light sources to create a particular emotional setting.

  • Bright light stimulates us, while low levels of illumination quiet our senses.
  • Too much bright light hurts our eyes and make us feel jittery.
  • Insufficient lighting causes eye fatigue and headaches.
  • Insufficient lighting is linked to emotional stress and to physical ailments.
  • Low light level or harsh contrasts produce eyestrain.
  • Directly visible light source cause irritation and disturb tranquility.
  • Artificial light does not replace the calming effects of natural daylight.
  • Absence of natural daylight triggers depression and poor immune defenses.

Lighting brings benefits in many ways, but notice how an excess or a lack of artificial light brings about the same harmful side-effects. Choosing between a glow and a bright light involves understanding the effects of light on our mood. Uniform lighting is adequate for working, but is rather boring; people feel more comfortable with lighting from many sources. Combinations of contrasting brightness and darkness cause dramatic and lively changes in an ambiance as long as they remain balanced. Use of artificial light sources add variety and vivacity to our spaces and our lives only by respecting our emotional and physical comfort.

02 June 2008

No retrofitting please!

Early attempts to apply LEDs to general lighting failed because LEDs did not meet the required luminous efficacy or color requirements. Technology has reached a point where using LEDs for general illumination is now a viable option. But, taking over where I left, I believe trying to repurpose existing technologies' lighting fixtures to house LEDs is inappropriate.

LEDs represent a disruptive innovation for the lighting industry. A disruptive innovation is technologically straightforward, using off-the-shelf components put together in a product architecture that is often simpler than previous approaches. These products are usually less capable in the traditional aspects of what is required in established markets, but feature different bundles of characteristics that were not considered important in the past. Applied to LED technology one may think of energy efficiency, resistance to vibration and unidirectional luminous flux, to cite a few.

Conventional approaches to developing power LEDs based general lighting often involve retrofitting existing fixtures to house the new technology. Many early attempts simply used traditional lighting standards and housings instead of investigating the challenges and benefits of LEDs. But LED technology breaks traditional rules, and it quickly become apparent that old thinking cannot be applied. A LED module may physically fit into an existing fixture’s housing, but that housing will not leverage the inherent qualities of power LEDs, mainly because:

  • standard housings do not handle the challenges of LED thermal management, which is vastly different from those of incandescent or fluorescent lighting.
  • optical design used in most traditional fixtures does not maximize the LEDs' efficacy.

Furthermore, power LEDs last a very long time, and the expectations for fixtures' life span are getting higher. Typical specifications for LED lighting fixtures tend toward more durable, longer-lasting products using higher quality materials than those commonly associated with other lighting sources. A state of the art LED module in a cheap fixture would defeats the purpose.

A disruptive innovation is not the same as a radical innovation. A radical innovation is just a major improvement along an existing performance dimension. A disruptive innovation creates a different performance dimension, one that is not particularly important to incumbent firms' most profitable customers. Let’s hope lighting industry experts accept the change and gain a better understanding of how to capitalize on that technology.

01 June 2008

The incandescent frame of mind

There is one recurrent bias in many writings about the coming of age of LEDs for general lighting: the author always assumes the only allowed form factors for LEDs to become successful have to be similar to those of the other light sources technologies we know today. Or to put it more simply, that LEDs are only going to succeed in the “retrofit” market. I take as example this attempt at describing how LED based fixtures are now able to compete with traditional general lighting fixtures.

Beyond the fact that the post speaks a little too much about one single manufacturer to be exhaustive, and try to draw general conclusions based on this narrow view point, I believe it gives a wrong perception of the issues at stake by providing the wrong examples. This is particularly true of the cost based examples. But I am ready to assume this has been caused by jet lag and "red eyes"…

Let’s examine the "much work remains to be done to get the costs down" example. First of all it sounds based on that ubiquitous chart found all over the web comparing luminous efficacy of light sources that everyone makes its own. Let’s say it makes me suspicious when I see a comparison using a "800 lumens" figure as a basis for calculation… But it is more the peremptory conclusion that "cost" must be driven down that makes me uneasy.

After all it is nor fair nor possible to compare the price of an incandescent bulb with a “15-20 watt LED”. Doing so we are not comparing apples to apples, but rather commodities with luxury goods, and ultimately we only propagate marketing BS.

As a matter of fact, the "cost" of this 15-20 watt LED light source is a retail price. Knowing that at semi-gross prices this same light source is coming out at around $27 (without volume discount), the only valid conclusion one can draw from the example is that the retailer is taking a three fold markup. And this cannot be called the cost of LEDs.

Moving on to the “kitchen cans” example, we can repeat the same calculation. This time taking into account the additional elements necessary to create a retrofit light source, namely a constant current driver ($5), an anodized extruded heat sink ($2), an optic ($3), an outer fascia ($1) and fixtures ($1). We are now approaching the $40 for the bill of material. The resulting product will probably be assembled in China, adding another $5 to the cost. Once again the example only demonstrate the three fold margin applied by the retailer on the product.

However, I agree with the author that “only the most elite pocketbooks will open for LEDs” at this price. Like they did for incandescent bulbs when electricity lighting took over from gas lighting… But what a cumbersome way to say that most retailers are pricing LED retrofit light sources as luxury items! Hasn’t it always be the case with emerging technologies?

Nonetheless, to return where I started, I believe the author missed an important point. Power LEDs are a disruptive innovation and trying to mold them into the previous technologies form factors is flawed. LED general lighting will really take off when designers, writers and customers alike will step out of their “incandescent” frame of mind.

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Form is the visual shape of mass and volume. Light makes form legible. There is no form without light.


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