Sunday, December 30, 2007

Induction Lighting FAQ

Michael Ng, Director of Marketing for Amko SOLARA Induction Lamps, describes briefly the applications and comparisons of different lighting sources with Induction Lighting in this short interview.

Original post can be found here:

1. What is the difference between traditional fluorescent light and induction light?

An induction light is similar to a fluorescent light in that mercury in a gas fill inside the bulb is excited, emitting UV radiation that in turn is converted into visible white light by the phosphor coating on the bulb. Like fluorescent, the phosphor coating determines the color qualities of the light. Fluorescent lamps use electrodes to strike the arc and initiate the flow of current through the lamp, which excites the gas fill. Each time voltage is supplied by the ballast and the arc is struck, the electrodes degrade a little, eventually causing the lamp to fail. Induction lamps do not use electrodes. Instead of a ballast, the system uses a high-frequency generator with a power coupler. The generator produces a radio frequency magnetic field to excite gas fill. With no electrodes, the lamp lasts longer. Induction lamps, in fact, last up to 100,000 hours, with the lamp producing 70% of its light output at 60,000 hours. In other words, their rated life is 5-13 times longer than metal halide (7,500 to 20,000 hours at 10 hours/start) and about seven times longer than T12HO fluorescent (at 10 hours/start).

2. How efficient or energy saving is it?

While induction lamps can generate more lumens per watt compared to metal halides (80 v. 70), it is not as efficient as T5’s that powers 100+ lumens per watt.

3. What kind of application is induction lighting for?

Induction lamps are ideally suited for high-ceiling applications where the lamps are difficult, costly or hazardous to access. They are also ideally suited for such applications where the advantages of fluorescent lighting are sought but a light source is needed that can start and operate efficiently in extremely cold temperatures. As a result, induction lighting is a suitable for a wide range of applications, including not only warehouses, industrial buildings, cafeterias, gymnasiums, etc., but also signage, tunnels, bridges, roadways, outdoor area and security fixtures, parking garages, public spaces, and freezer and cold storage lighting.

For some applications, well-designed linear induction hi-bays are better than well-designed HID hi-bays with regard to glare, contrast ratios and vertical footcandles. Here are two examples. Imagine yourself playing volleyball. As you follow the high arching ball coming towards you, would you prefer having to look up into a point source HID bi-bay or a 4ft long induction hi-bay with one 400W lamp? Imagine yourself as a forklift driver having to deal with vertical surfaces and load and unload pallets in high warehouse racks. Compare vertical footcandles with well-designed 4-ft., 8-ft. or extended-row linear induction hi-bays mounted in the middle of rack aisle row parallel to the racks with well-designed HID hi-bays mounted in the middle of rack aisle row. Envision how easily a loaded pallet can block the light from the point source HID lamp.

4. What are the increased costs to use induction lighting?

The increased costs occurs in the induction systems themselves – which could be 5 to 6 times more than metal halide systems, and also in new fixtures, which can inflate payback periods and reduce return on investment. But you also generally get a 30% reduction in capital and operating costs immediately from the reduced number of fixtures made possible by the higher light output. You also get 15% more efficiency just because the induction system (lamp and electronic ballast) is more efficient. Apply that over ten years plus replacement and maintenance costs and suddenly it makes a lot of sense to go into induction lighting systems.

5. What advantages are there for induction lights v. metal halides

I think the biggest advantage that induction lighting has over metal halides is the ability to instantly start and shut off. The reason I said that is because we see the fastest growing replacement of metal halides to induction in areas like tunnel and street lighting. Why? Because a driver driving at 55mph cannot afford to be inside a pitch dark tunnel for more than 2 minutes waiting for the metal halides to restart! Many tunnel lighting fixtures have an emergency direct current backup where the light will run on batteries until the electrical power is back up. Metal halides, once turned off in an outage require a cooling off period for the gases to return to a solid state before it can restart itself. A solution to this problem is to install fluorescent lamps such as T5’s or CFL lamps, as emergency lamps that will light up immediately. But that in turn increases the installation of fixtures and lights, as well as periodically testing these back up lamps to see if they are still functional. Not to mention that these are usually installed in minimum quantities and in low wattages that barely suffice as emergency lighting. Our tunnel fixture installed with SOLARA induction lamp will switch to DC power immediately and keep the tunnel lit as if nothing has happened.

Another advantage induction lighting has over metal halide is lumen maintenance. Most significantly, at 40% of service life, metal halide’s light output and efficacy experience severe degradation. A 400W metal halide lamp, for example, may produce 36,000 lumens but 25,000 at 40% of life, a 30% decline. Therefore, unless the lamps are periodically group-relamped, a large system’s “average” performance over time is much lower than its initial ratings. Tests on the 400W SOLARA Induction lamps on the other side, retains 82% output after 20,000 hours (that’s already more than the rated hours on metal halides) and still puts out 70% after 60,000 hours. You would have replaced at least 6 metal halide bulbs by then and the last bulb will be running at 50% output.

6. How does induction light compare with LED?

Well we all know that Light Emitting Diodes are not considered for general lighting purposes because of its limited brightness and poor color rendering, but this is compensated by its high reliability and high color temperature. It is still a common mistake that many people make thinking that higher color temperature, say 6000k, means higher brightness.
LED however, does have the same theoretical lifespan of 100,000 plus hours as induction light, given that the integrated chip does not fail before the diode. Many LED manufacturers neglect to fit a decent high temperature IC or integrate some kind of heat dissipation device and their LEDs fail after only 10,000 hours.

Induction light on the other hand, offers the same stability and lifespan as LEDs but is available in much higher wattages and brightness that it can truly replace incandescent and discharge lamps as the next revolutionary lighting source. In the end, both are emerging technologies and are getting as much attention and improvements as the other so you can expect these problems to be corrected in the near future.

7. What about T5?

The T5 is a very effective fluorescent light because it tops 100 lumens per watt whereas the SOLARA generates between 80 and 85 lumens per watt. The only problem is T5 is not available in higher wattages – you can generally find a T5 tube up to 58W, but there is a German manufacturer that produces a 90W T5 at a relatively high price. When you are limited to small wattages, you have no choice but to use multiple tubes together to increase the total lumens output, hence increasing your material costs in terms of additional inventory and lighting fixtures.

6 comments:

hess said...

very well

Anonymous said...

Re your item #6, properly designed LED luminaires are very capable of high wattage and very bright outputs, color temperatures from less than 2000K to over 6000K, and CRI's to 85.

small potato said...

I am confusing that, whether a backup battery can be apply on the induction lamp as an emergency lighting ??

Anonymous said...

I am confusing whether a backup battery can be apply on the induction as an emergency lighting ??

alen mcmilan said...

I really like your given article on difference between traditional fluorescent light and induction light.I think T5 is really better one option in the LED lights.
LED Manufacturers

seecol said...

very nice blog,i really liked it,as you have nicely explained comparison between Induction lampsand other lights,these lights are Eco-friendly and energy saving.Thanks for sharing the information.