Incandescent vs Fluorescent bulbs and globes

Pros and Cons

Had this dilemma - whether to choose one over the other (pros and cons to go incandescent vs fluorescent.)

Could the best way to decide be based on someone else's experience?

One day ...  how the shift started

We just realised that one too many bulb had become short lived. It was as if manufacturers were cutting too many corners. Kind of saying - we invested enough R&D into other light technologies it was time to put our money where our mouth was. In other words, manufacturers have already decided where to tilt the incandescent vs fluorescent debate.

Jump to Incandescent vs Fluorescent wattage comparison >>

Pros and Cons
Coloration problems

Wattage comparison

Shape facts
Light output
Surface treatment
Price comparison

Lesser known evils Related Articles, Resources
We started using fluorescent bulbs there and then. (We are quite cautious with LED lights.) But trial and error is always the way as there are already a lot of places and uses where even fluorescent bulbs will not suffice. Still, wherever we can we replace our incandescent bulbs with fluorescent ones.

Not to mention that I like the silly look you can have with fluorescent light bulbs. In a lamp designed for an incandescent, similar wattage fluorescent bulbs will be too big for their own good. They will stick out - a bit like curious little light creatures. Increase this effect by deliberately using spiral bulbs instead of pear shaped ones. Not for the pedantic!

Over the period of several years now, we had only one bad experience. See, incandescent bulbs burn out very unpredictably. (Quite often at the worst possible time.) I don't know how it will be with fluorescents on the long run though. For many-many months now we didn't have to replace any of them. But one we did. Read on to find out why ...

Coloration of incandescent vs fluorescent bulbs

Incandescent is generally warm white due to the red and infra red component. Fluorescents can have various light effects due to different color temperatures.

Usage Coloration

If you happen to see your brand new fluorescent bulb burning with an unusual color (we had violet), don't think that the light become brighter over time. Because it won't. We thought - hey let's give it a little time. Bulbs are only 'human', they need time to warm up - then we'll see. What we saw was nothing like that. The coloration got more and more violet - yes. But it never got brighter. (In hindsight, it is likely that the internal coating was too thin, but we didn't know this back then.)

HAIRY Quick Points
Fluorescents - bulbs are filled with mercury gas that is carbon-expensive to recycle. Coated inside with phosphor that emits light when excited.
fluorescent tube - has to be long: arc IS the light
Have to be long enough for the phosphor surface to give off enough light so it is packaged
in one long tube (the old way) 
short fluorescents - need to be wound up or wound up like this "bulb"

Learn more about Compact Fluorescent Light Bulbs here
Incandescents - need a stucture that burns something in the middle. Unfortunately, this way it pollutes inordinate amounts of heat and light ...
incandescents - need a near sphare shape To spread light (and heat) evenly they are built with a round shape. And if you focus light to lose less of it - making it a reflector - turns pretty hot too.
Photo courtesy Wikipedia
Anyway, do promptly what we decided to do eventually. Swap it for a good one or return for a refund while you can.

Shape comparison

This is an area where an incandescent can hardly compare with the wild variety of fluorescent light fixtures. Fluorescents come in many shapes including tubes, spirals, pear shapes and possibly even spheres (I yet to see one.) The problem you will often face though is that the shape you find is not the shape you look for. Retail stockist are quick to reorder them on demand, but still very cautious to reorganize their stock light to your incandescent vs fluorescent dilemma.

Light output comparison - incandescent vs fluorescent


Overall they match in final brightness. This is because it takes some time for fluorescents to "lighten up" after a lower initial brightness. In the end I would give a slight edge to incandescent lights, but this could very well be a personal preference.

Wattage / Brightness comparison table

Common household sizes

Table Use / Description / Update

100 20-27 1250-1750
Click inside table for more information.
Same light
range (lumen)
40 7 400-500
50-60 10 500-600
75 11-15 600-1150
90 18 1150-1250

Track back Wattage / Brightness comparison table:

You will want ot use this table when:

  • You don't see as well as you would like to, but prefer to be independent and shop by yourself. The problem for you is that Equivalent Wattage Values are often printed WAY too small. In fact, they are often too small for just anybody. Full stop.
  • You discarded the original package. On the base of your new light bulb its wattage is clearly marked, but equivalent wattage of an incandescent bulb (or globe) is not. What a bummer ...

  • To get similar if not equivalent brightness, choose your compact fluorescent light bulb according to this Wattage / Brightness Comparison Table. Within range, you will get very close to equal light output.

    IMPORTANT: Compact fluorescents usually gain full brightness in about 30 seconds to a minute after you switch them on. Even so, my experience is that the brightness you get then from a fluorescent may be similar - it will still remain a bit shy of what I used to get from an incandescent bulb in the same range.

    Related Articles

    As you can see I expanded my initial table a bit.
    In the first two columns I left the information about similar wattage the way was noted on the actual products. But I also looked up measured data on brightness (or light output) calculated in lumens and added them in the third column. On average, the lower figure in that brightness range applies to a fluorescent and the higher to an incandescent bulb. So for example a 7 Watt fluorescent bulb tend to have an output closer to 400 lumen while the highest output of a similar 40 Watt incandescent bulb would closer to 500 lumen.

    Just one more thing:
    Light output there means the brightness you get after about 100 hrs of operation. (Somewhat confusingly, this is called initial brightness in lighting lingo.)

    The interesting thing that comes up is a confirmation in numbers that the similar wattage noted on the products does not necessarily mean same (or similar) brightness.

    Bulb and globe surface treatment

    Incandescent comes with a clear or frosted surface. Fluroescents are frosted. (Am yet to see a fluorescent other than that - and it is likely I won't.) You see, without the phosphor internal coating that comes across as frosting light would be bluish violet and ultra violet.

    However, some tinkerers use stuff other than phosphor. Think they put titanium dioxideoutside the bulb and claim that the reaction of this thin surface with the luminescent light coming from within changes the ionic content of the air surrounding the bulbs. They propose that these spiral bulbs purify your indoor air making you healthier. Watch out. While there are some better products, most of the ionised air mumbo-jumbo I found was little more than plain quackery.

    Price comparison

    For determining on your dilemma (incandescent vs fluorescent) I should have started with this comparison. However, on the face of it price doesn't tell much; - At least not the full story.

    It is true that fluorescents are about 3 times more expensive than using incandescents for the same job. But is it the same job they do? Not quite. The working life of incandescents is on a steady decline - at least this is my experience. The fluorescents we got to replace them have already worked three times longer than the old ones ever had. But these ones are still going. So keep buying the old bulbs if you cannot afford the new, but you'll likely get less and less value for your money with incandescents.

    Fluorescents on the other hand are gaining more and more popularity on construction jobs that are managed into facility management and maintenance contracts. A ten story new building with 100 rooms at each level would have about 10-30 thousands new light fixtures. These are the real demand on the problem incandescent vs fluorescent light bulbs. But this is an exclusive high-end market, which is unlikely to drive pricing very much down.

    Incandescent vs Fluorescent:
    The lesser known things you need to look out for.


    Two lesser known "evils"

    Replacing everything with halogens saves energy is no more then an urban myth.

    Handling: Fluorescents are "look don't touch" ligthts.
    The popular belief that bright incandescents should be replaced with halogen down-lights - wherever possible - doesn't hold. Where they are there for ambient room lighting use compact fluorescents instead. This is because to achieve the same level of illumination you'd need too many halogens. This in turn will use much more energy, not less.

    And when you need bright spots, consider some LED bulb washers and floods to compare effects - and possible savings - instead of halogens.


    Take extra care when handling compact fluorescent light bulbs. Remember not to touch the bulb with bare hands. It is a less known fact that the grease deposited from your fingers may reduce the lifetime of your compact fluorescent bulb or globe.
    (You need to take similar care as you do with halogen light bulbs.) Use a maintenance glove or a clean piece of cloth.

    These bulbs you can touch with fingers of course. But it is always wise to clean them before use, as burnt grease is much harder to remove. As a lot of light an incandescent bulb gives off goes into light pollution anyway, (that is light lost to heat) occasional mishandling in this department will not have significant effect on normal usage.

    Related Articles, Resources

    Learn more about compact fluorescent bulbs

    About long life incandescents bulbs.

    Some thoughts on LED bulbs as flood lights

    (links open new window)

    Another comparison is based on light output (brightness) per watt (also called "efficacy")

    Comparison typical initial light output and lifetime

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