Flourescent Lighting Question

Who says they can't be? A number of companies have developed wide, flat fluorescent lamps -- with varying degrees of success. Some of the early developers have gone out of business since flat fluorescent lamps have problems with capacitance, electrostatic attraction, cathode sealing, non-uniformities and glow 'beading' in the glowing gas, to name a few issues. Here's an example of some small flat lamps that were made about 15 years ago:

http://statusreports.atp.nist.gov/reports/93-01-0109.htm

These days you can make a flat lamp using LEDs (either as an array of LEDs or by using a few LEDs with a flat light guide) and get more lumens per watt without the need of a high voltage ballast.

I sure wish they would put more effort into LED's. These compact flourescents don't last anywhere near as long as advertised. I lit up my basement with them, (about 10 or 12), half are dead in less than a year, and I don't go down there very often.

They're very suseptible to voltage fluctuation, this is your sign to protect your sensitive equipment.

The compact fluorescents are the only thing I've ever had a problem with. I do have a surge protector on the computer.

And outside in the winter, or any un heated area for that matter they are useless!

That may be part of the problem. The basement is unheated, although it doesn't get below, probably mid 40's. It does take them a while to reach full brightness.

Banning incandescents has already begun, which really pisses me off. If they are going to force us to use cfls, they should work as advertised. I'll never understand the utter stupidity that runs through the local, state and federal government.

I've got 5 burned out cfls in the basement right now. Of course they contain toxic material, unlike incandescents.

One of the biggest issues is installing and/or changing the lamps- ALL fixtures have been designed with clearance for round lamps 1.5 inches or smaller in diameter.

IF a lamp that is only 1.5 inches wide were used- should not be a problem but it is a challenge to get adequate lumen output from just the "flat" side to match the equivalent circular shape, with its inherent larger surface area.

You would not gain anything by making the tubes wide and flat. Fluorescent tubes emit light equally in all directions so half the light would be emitted towards the fitting. If you study catalogues of when they were first introduced, almost all the fittings had the axis of the tube sited at the focus of a rolled metal white enamelled parabolic reflector, so that the light was directed to where it was needed. In later models this feature was dropped. A case of aesthetics winning out over efficiency. The reflectors used to attract electrostatic dust and I can remember when lamp cleaning throughout a factory was a routine maintenance task.

Fluorescent tubes generally replaced incandescent light bulbs, and in their time were a breakthrough in high efficiency, high intensity lighting. A tube uses less glass than a rectangular section, it is stronger so that you can use thinner glass, and it is easier to extrude and seal. This makes manufacturing much simpler and cheaper. Usbport has listed some of the technical problems associated with non-tubular so I won't repeat, but several factors associated with how they are handled during manufacture also make a tubular lamp preferable.

LEDS emit a 160° cone of light so don't lose any light towards the fitting. This makes them much more suitable for large flat lighting, but I think that in the next few years improvements in organic photo-diode technology will allow illuminating panels to be printed onto walls and other flat surfaces. The small amount of mercury in tubes is already causing concern over their waste disposal and this will hasten the demise of the fluorescent tube.

actually fluorescent lights do not emit light equally in all directions, a circle or sphere or circular tube emits light equally, because the sides or outer surfaces are equal distance from the centre.

Nothing spectacular about this knowledge, a flat tube will emit more light at the curvature or ends/sides than the flat surface as there is more surface area in that confined space of the curve EG: a one inch edge curve one inch apart from each flat surface is three and a half inches of surface in one inch of the tube, so the edges would glow far brighter than the balance of the tube, though this is not the reason they do not make them that way - total light being the value point regardless of how silly it looks.

the reason is the same as all mechanics, a sphere or a tube absorbs impact at far greater ranges than a flat surfaced object, tubes and spheres are stronger, you would need tougher glass and the cost would increase too much against current costs. Have no fear a previous answer is indeed correct Fluros days are numbered, they are antiquated and bad for you eyes to boot.

Enerventure,

Are you sure? The visible light from a fluorescent tube is from the phosphor chemical coating on the inside surface of the bulb. This coating must absorb the UV radiation from the low-pressure mercury vapor arc inside the tube. Therefore light output is directly dependent on the amount of UV light absorbed. Getting a uniform arc across a flat area is more difficult than within a tube. Buried in my statement above and hinted at in your comment is the real reason why fluorescent tubes are not flat. The low-pressure is a fairly high vacuum. Spherical and tubular glass bulb shapes are much stronger than flat shapes--the flat ones would have the two parallel sides pulled together, or would break fairly easily, or would need much thicker (and heavier) walls.

--JMM

Just chiming in here: Why does it matter ?

Although my opinion is only that, I couldn't care less about CFL's, and fluorescent lighting is something that should be phased out ASAP.

For all those on the CFL bandwagon, get off. The world is being pushed into an era of "green this" and "green that", all about the environment and your "carbon footprint".

Anyone care to postulate on what the SHORT-long term effects of filling every landfill with fluorescent lightbulbs ?

I am in NYC, some states are more lenient than others, but you basically need a hazmat team to clean up a fluorescent bulb mess. You must be careful, and if it gets in your rug be more careful. I also do NOT suggest vacuuming up any of it. You would effectively be taking any residual mercury vapor and dispersing it in the air.

I agree with some of these posts about CFL life because in my experience I have had to replace almost as many as any incandescent bulbs I have ever had. One issue for me about fluorescents is that a bulb is as reliable as the fixture, and I have some ancient Fluorescent fixtures that even with heavy use have very long bulb life. Of course these fixtures are VERY old, and all the new ones I have bought in the past ten or so years go through bulbs all the time.

What all people must do, is start using LED lighting systems, they are non toxic to the environment, and they give you the lowest in power consumption, which IS the goal here.