LED: The Tiniest Giants
If you’re remodeling or building a home, you know that California has some of the toughest energy codes in the nation, and getting tougher every couple of years. From a lighting perspective that means that lighting must be highly energy efficient.
The tiniest giant
Luckily, we have a tiny new player in the world of lighting: Solid State Lighting (SSL) better known as LED lighting. SSL has taken the lighting industry by storm and will soon knock out inefficient contenders such as incandescent, halogen and many fluorescent lamps by providing warm, dimmable, long lasting energy efficient light.
SSL is the best lighting innovation to come along since the Edison lamp, in fact, there is nothing on the horizon that can compete with this light source for the next 20 years, and SSL is projected to get better and better in 6 month cycles.
Why? Because SSL produce light via an extremely energy efficient process called electroluminescence thereby eliminating the need to heat a filament in a gas filled vacuum tube like incandescents, or exciting gases in an arc chamber as in florescent lighting, both of which are inefficient ways to produce light.
Instead, SSL only have to move electrons over a tiny distance to produce light. The LED chip itself is extremely small and requires very little energy to produce huge amounts of light. Currently, a 1 watt LED is only about 1/8” square and can produce over 150 lumens per watt (LPW) of usable light. By contrast, a 100W incandescent lamp only produces approximately 17 LPW, and fluorescents generate between 50-100 LPW – energy efficient, but still not as efficient as SSL.
This light source which until recently was considered too blue and too expensive for residential applications, now easily produces excellent color temperatures rivaling the purest white light from halogen lamps, outclasses any fluorescent light source, and is falling closer and closer to an acceptable price point.
When considering the cost of SSL, one must accept a paradigm shift in how you calculate lighting costs and its associated value. Historically, lighting cost was determined purely by the cost of the fixtures, and lamps were considered a disposable commodity. With SSL lighting there are more criteria to consider: fixture cost, energy consumption, lamp efficacy, demand on cooling systems and lamp life. These parameters were given only marginal considerations by homeowners in the past, but going forward they will be given a bigger consideration especially since lighting is one of the highest energy consumers in the home.
SSL is not a disposal commodity; you can expect to use a typical SSL source for over 15 years. That’s longer than most people keep a car, or most appliances, so this product should be given the same consideration that one gives to choosing big ticket items such as flooring, appliances and surfaces.
From a green perspective, SSL are considered very environmentally friendly; in fact, they are environmentally friendly from production, through usable life, to disposal.
has over twenty five years experience in high-end residential construction, design and engineering. Alfredo established Techlinea Inc. in 1985 to provide quality lighting design services to discerning clients throughout the US and abroad. Prior to the founding of Techlinea, Alfredo was principal and partner of Electric Connection Inc., and was responsible for designing and installing electrical and lighting systems for many notable residences throughout the San Francisco Bay Area. He combines a deep understanding of lighting technology and design with a unique blend of creative vision, hands-on technical expertise, and collaborative style to make Techlinea sought out for projects worldwide.
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Hi Alfredo, You mention SSL now “easily produces excellent color temperatures rivaling the purest white light from halogen lamps”. I’ve never see a LED’s CRI over the high 80′s or very low 90′s. I’ve also heard serious doubts about the credibility of manufacturers’ CRI claims. Do you know of specific brands or models that achieve 100 (or anything close)?
Hi Alfredo,
My initial test was with the type you show and all failed (some individual LED’s dead) within 3 months or so.
I currently have 5 x MR16 3watt high efficiency LED’s mixed with my normal MR16 50w halogen downlights, 3 in the kitchen and 2 in the living area. The kitchen one’s have been in for approx. 2 years now. Just some general observations.
1. the LED’s give approx 50% equivalent light output
2. the LED’s are very directional (no diffuser fitted)
3. they switch on/off immediately with no visible lag
4. very minimal heat generated from the light side although the heatsink deos generate considerable heat which then dissipates into the roof space or closed fitting
5. I have no doubt that within a short period they will have a near or equivalent light output as their halogen counterparts. All the companies selling these MR16 and PAR10 LED’s overstate the comparable light output against existing lighting. Perhaps because they are promoting them!
Paul,
I don’t believe that I endorsed any particular product in my article.
I don’t particularly endorse LED MR-16s either, I haven’t found one LED
MR-16 that I really love yet, but we’re doing a lot of comparison still.
Frankly I’m more interested in working with fixtures with integral SSL light engines or chips. In this setting the entire fixture has been designed and engineered to optimize the LED output with optimum optics, heat sinks and
reflectors. There are some decent LED retrofit inserts, but I prefer
the whole fixture.
As I mentioned to Geoffrey, check out Xicato LEDs these are very bright and produce a very crisp white light, unfortunately they don’t make MR-16s or retro-fit products they only OEM for lighting manufacturers right now.
Regards,
AZ
Geoffrey,
For some reason my original response to your post didn’t get processed
but I responded that there are LED manufacturers that do have led
packages that produce high 80s-95 CRI. Check out Cree, Nichia, philips and Xicato
LEDS. we have a sample in our office of a Xicato LED chip that is 8W, 95cri
3500k. When tested side by side with a halogen lamp the only way I can tell
which is the LED and which is the Haolgen was by the striation pattern caused
by the MR 16s reflector. The Xicato is Made inthe USA and based in Silicon Valley.
In order to avoid the hype, stick to LEDs that have undergone testing have LM79,LM80 cerfication by DOE.
Keep in mind that the CRI by itself does not indicate what the color temperature of the reference light source is; therefore, it is necesarry to cite the correlated color temperature (CCT). Remember that even though the incandescent lamp is condsidered 100 CRI, everyone who has ever tried to match black and blue under incandescent lighting knows that its not easy task.
AZ