Just like buying eggs at the supermarket, buying light bulbs can turn into quite the task with the stupefying selection provided. Luckily, we have come up with an idea.
Here is a comparison of the light bulbs you are likely to purchase for your house or business, including their lifespans, energy efficiencies, and general workings — just don’t forget to check if it’s a bayonet or screw cap...
A household that invested $90 in changing 30 fixtures to [Compact Fluorescent Lights] would save $440 to $1,500 over the five-year life of the bulbs, depending on your cost of electricity. Look at your utility bill and imagine a 12% discount to estimate the savings." - Money US News
Incandescents
How common?
Let’s start with the basics: incandescent bulbs. These are your classic light bulbs that are in most houses and probably yours right now. These bulbs also feature commonly in torches and car headlights, not to mention in cartoons above heads with bright ideas. They are also used as those small 'candle'-like lights in multi-bulb candelabras.
How do they work?
They have a generic bulbous shape with a characteristic metal filament inside. This metal filament is made of tungsten and is a bridge for electricity to surge over. As the electrons flow over the filament, it heats up so much that it begins to emit light. This is comparable to heating up a cattle brander or other metal implement where it glows red and eventually white-hot. Well that’s your light: white hot (have you ever tried to change one while it was still on? Youch!).
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Halogens
How common?
Also known as ‘tungsten halogen lamps’, halogens are quite common. Because they can be made smaller than incandescents, they are used for smaller applications such as in penlights.
How do they work?
Halogens work similarly to incandescent bulbs, but instead of having a vacuum or some other gas inside the bulb, halogens contain...you guessed it, a halogen gas. Normally, the tungsten filament inside an incandescent evaporates, weakening the filament and eventually leading to a blown light. The halogen gas that fills the interior of halogens ‘feeds’ the tungsten filament, thus prolonging its lifespan.
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Fluorescent
How common?
Fluorescents lamps or tubes are common. These are the ones that flicker in long corridors, largely in horror films.
How do they work?
These lamps use an entirely different process for light generation. Where incandescent lights heat metal up till they emit heat and light, fluorescents take advantage of a chemical reaction known as fluorescence. Fluorescent lamps contains mercury gas at a low pressure. Electricity is ran through the system, exciting the mercury temporarily. The mercury calms down, emitting light on ‘its way down’.
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Compact Fluorescent Lamps (CFL)
How common?
These fluorescent lights are more efficient than regular fluorescents. Some are designed with a characteristic ‘helical’ or coiled pattern. They are increasing in popularity as their value and lifespan are increasingly recognised.
How do they work?
CFLs work the same as the tubular fluorescents, but they are more compact, with the tube coiled in to form a compact shape.
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Mercury-vapour lamps
How common?
Common, but not in the household. These are the bulbs that line the streets on streetlights. They are in the process of being banned worldwide due to their poor efficiency.
How do they work?
They also work by exciting mercury vapour inside an enclosed bulb.
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LEDs
How common?
Light-emitting diodes are very common, but not commonly as a lighting source. LEDs are a common component of circuitry such as remotes, traffic lights, and camera flashes.
How do they work?
LEDs utilise a process known as electroluminescence, using a material known as a semiconductor. Electrons are ‘coaxed’ to enter electron holes within the semiconductor, thus becoming excited and emitting light.
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Edison bulbs
How common?
Not very. These bulbs have long and characteristic filaments, giving a vintage look.
How do they work?
Edison or vintage bulbs are incandescents. LED imitations are being produced to maintain the look of these globes, but upkeep the energy efficiency and longevity of LEDs.
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Light bulb comparison table
| Measurement | Incandescent | Halogen | Fluorescent | LED (Generic) |
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| Electrical power (W) | 60 | 42 | 14 | 10 |
| Light output (lm) | 860 | 650 | 800 | 800 |
| Luminous efficacy (lm/W) | 14.3 | 14.42 | 57.14 | 80 |
| Color temperature (K) | 2700 | 3100[96] | 2700 | 3000 |
| CRI (Colour fidelity; 100 = natural colouration) | 100 | 100 | >75 | >85 |
| Lifespan (hours) | 1,000 | 2,500 | 8,000 | +25,000 |
*Source: Wikipedia
compare led lights to incandescent
Hi Alan,
Thanks for your question.
LEDs have longer lifespan and lower energy consumption than incandescent lights, but they are also more expensive.
Cheers,
Anndy