If you know anything about LED lighting, you likely know that LEDs are considered to be energy-efficient fixtures that help save money on electrical costs.
And, although that is only one benefit of switching to LED lights, it is certainly a big one. For most people in the commercial and industrial, the question isn’t so much, “are LEDs energy efficient?” but rather “How much can I save with LEDs?” And we’re here to answer that.
LEDs vs Metal Halide Lumens Equivalent Chart
Loss Of Lumens
The degradation of lumens that most fixtures experience can be exacerbated even further by what is known as loss of lumens.
Loss of lumens is the term used to describe the lumens that leave the fixture but never reach the intended surface area.
This is typically the result of multiple reflections from a fixture’s housing.
Loss of lumens can be calculated simply by knowing a material’s reflectivity.
For example, aluminum generally has a reflectivity of 90%.
This means that every time light bounces off of it, 10% of the lumens will be lost. But, it won’t stop there.
Oftentimes a light is reflected several times before it actually reaches the surface area, meaning that even at peak lumens capacity, if your fixture has any reflectors, you’ll never be getting the max lumens.
Unfortunately, metal halide lighting needs reflectors because the bulbs are not directional, and therefore require something to ensure that they shine in the correct direction.
Luckily, LEDs are directional bulbs and function perfectly without reflectors.
Lumens Life Span
As you can see, in several of the instances above, the metal halide lights have a higher lumens output.
But this number can be a little misleading, and there are two issues with judging a light’s brightness solely by its lumens output.
First and foremost, we need to discuss the lifespan of the lumens.
Regardless of bulb type, each and every light will experience some form of lumen degradation as they are used.
However, some bulbs are worse than others… and metal halides are one of those bulbs.
As you can see from the graphic above, metal halide bulbs will suffer from a 70% lumens loss after only 10,000 hours of use.
LEDs, on the other hand, can run up to 80,000 hours before they experience the same amount of lumen degradation.
So even though a metal halide may be initially brighter the light will quickly diminish and be outshone by a comparable LED.
As you may know, there are many wavelengths on the light spectrum that are not visible to the human eye.
So even thorough a photometer may be able to pick up on them and add them to lumens value, the shine on the invisible spectrum has no effect on the surrounding environment.
This means that the claimed output isn’t what you can actually see. An HID bulb like metal halide generally wastes a significant amount of its energy consumed producing heat.
LED Light, in general, produces very little heat and most of the energy consumed is used to produce light, which is the true purpose of lighting anyways.
CRI – Color Rendering Index
CRI, or color rendering index, is a measure of a light’s quality. And most often, the higher the CRI, the brighter the lights appear. A high CRI also helps the eye discern between color and creates much better contrast, which is why studio lights usually have an extremely high CRI.
Metal halide bulbs, on average, initially have an extremely high CRI, but as the lumens begin to degrade, so does the CRI.
LEDs are available in many different CRI ranges, so you can determine what is best for your facility’s needs and make a decision.
Savings & The Many Other Benefits of LEDs
As you can see, there are many benefits LEDs offer over HID bulbs like metal halides and high pressure sodium.
Perhaps the most significant is the reduced lighting bills and maintenance costs once you make the switch.
In the above graphic, you can see savings up to $353 in electricity costs per year by converting only one metal halide bulb over to LED.
The variation in our calculation accounts for the differences in cost of electricity across the USA.
If you know your cost of electricity, we can run a savings calculation for you. Or if you want, run one yourself by clicking here.
In real life, commercial and industrial facilities won’t just replace a single light. In fact, many of these facilities have hundreds of lights that need replacing.
If you can save $353 a year by switching one light to LEDs, imagine how much you could save by switching hundreds of bulbs to LED.
However, as we said, energy savings are just one small facet of LED lighting. If you want to know about the many others, you can read about them here.
But, even with only reduced electrical costs, LEDs superiority is pretty obvious.