If you’re on a mission to make your home more environmentally friendly, lighting is a great place to start!
Now that traditional incandescent bulbs have been phased out across the globe, attention has turned to their successors: halogens.
After brightening our homes for the last 60 years, are halogen bulbs next to be eliminated?
LEDs are far brighter than halogen bulbs. They have a lumen per watt ratio of 80-100 lm/W, compared to 16-24 lm/W for halogens. This means that LEDs emit much more light using much less energy.
So it’s no surprise that experts are predicting that LEDs will account for 61% of lights by the end of 2020.
LEDs may be bright, but at what cost? If you’re eager to find out more, stick around. In this article I’ll be discussing:
- How halogen bulbs work
- How LED bulbs work
- The brightness of both types of bulb
- How halogens and LEDs perform in car headlights
Difference Between Halogen and LED Bulbs
Before I get on to brightness, it’s important to understand how halogen and LED bulbs work. Let’s start at the beginning.
Much like traditional incandescent bulbs, halogens make use of a tungsten filament fitted inside a gas-filled bulb. Light is created by running an electric current through the thread until it is white-hot.
However, unlike argon-filled incandescents, halogen bulbs, as the name suggests, are packed with halogen gas.
When an electric current is supplied, the tungsten filament evaporates and combines with halogen particles.
Using halogen means that once the bulb is turned off, the tungsten can migrate back to the filament instead of depositing on the inside of the bulb. The halogen is then released and free to start the cycle again.
The addition of halogen expands the lifespan of the bulb since incandescent bulbs fail due to the filament degradation.
High pressure of halogen is needed for this process to work efficiently. So halogen bulbs are typically made from fused quartz, instead of standard fragile glass.
LEDs, whereas, are based on an entirely different principle that doesn’t require a filament.
LEDs generate light using a semiconductor. When a suitable voltage is applied, positively charged electrons can jump the semiconductor’s band gap and meet with negatively charged electron holes.
This reaction is called electroluminescence, and the result is photon production (light).
As I’m sure you can see, LEDs and halogens are worlds apart.
Halogen vs LED: Which Has Better Light Output
So how do these differences play out when it comes to brightness? Sadly, it isn’t a straightforward comparison.
In the past, wattage and brightness were directly correlated. The higher a bulb’s wattage, the brighter it would be.
But the introduction of LEDs disrupted this relationship. As a highly efficient light source, an LED can replicate a halogens 40 watts of light using just 10 watts of energy.
In other words, a 30-watt LED will be much brighter than a 30-watt halogen.
So it’s clear that the relationship between wattage and brightness is no longer linear. But why is this?
If you’ve ever touched a lit halogen bulb, I’m sure you’ll know that they get very hot. In fact, halogens waste 80% of their energy as heat, with only 20% being used to create light.
With LEDs, the complete opposite is true. They use 80% of their energy as light, and the other 20% escapes as heat.
Back to the question at hand, it became clear that a new yardstick for measuring brightness was needed. Introducing… lumens! Lumens are a measure of the total amount of visible light emitted by a light source.
An 18w halogen bulb emits around 220 lumens, while an 18w LED bulb outputs 1300.
Which Type Is Brighter?
But LEDs are available in a wide variety of brightnesses, so the two bulbs’ brightness is better compared by determining their lumens per watt ratio. This is calculated by dividing the number of lumens by the number of watts.
On average, LEDs have a lumen per watt measure of 80-100 lm/W. Halogens, whereas, typically have a lumen per watt measure of 16-24 lm/W.
In this regard, LEDs are a clear winner, since they emit more lumens using fewer watts. But that’s not all.
Since LEDs are available in a range of brightnesses and colour temperature, they’re much more customizable than halogens. This means it’s easier to find a bulb that fits your exact needs.
What’s more, LEDs reach full brightness immediately after being turned on and are unaffected by frequent cycling. That is, unlike halogens, they can be switched on and off for short periods.
Ultimately this means that as well as being brighter, an LEDs light is also more stable.
Are Halogen Bulbs Better Than LED For Car Headlights?
The debate between LEDs and halogens is often heard in the context of vehicle headlights.
Since the late 1970s, halogens have grown to become the most widely used automotive headlight bulb. They are compact and get the job done.
But over the last decade, a new type of headlight has emerged: LEDs. Audi was the first company to implement full LED headlights in 2007. Since then, lots of other car manufacturers have followed suit.
So which is better? Well, it depends on the car you have and the type of light you prefer.
LEDs are brighter, whiter, and longer-lasting than halogens.
While halogens typically cast a small yellow pool of light directly in front of the vehicle, LEDs cast a broader light pattern that makes it easy to see your entire surroundings.
In this sense, LEDs are safer since they allow for greater visibility of the road.
But retrofit LEDs may suffer from practicality issues. Heat is the enemy of LEDs, so many LED headlights require a heat sink that dissipates excess heat away from the diode.
Besides, LEDs operate at a lower voltage than halogens, so they need a transformer to step down the voltage supply.
It may sound simple, but the demand for extra electronics can cause fitment issues, as there may not be enough space in the headlight.
So while LEDs make better headlights, halogens are more practical and far more straightforward. If you want to explore the topic of LEDs in car headlights deeper, check out my other article.
To summarise, when it comes to brightness, there’s no competition between LED and halogen bulbs. LEDs are around 5 times brighter!
Soon enough, you’ll have no choice but to make the switch. In 2018, halogen light bulbs were banned across Europe and other continents are set to follow suit.
Did you know about the fundamental differences between halogens and LEDs? Have you ever tried LED car headlights? Let me know down below!