LED Equivalent Chart

1. 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 traditional lighting 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, high bay LED lights are directional bulbs and function perfectly without reflectors.

2. Lumens Life Span

As you can see, in several of the instances above, the metal halide lights have a higher lumens output on the comparison charts.

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. Lumens measure brightness and watts measure energy output.

Regardless of light bulb type, all lights 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 light 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.

LED light bulbs, on the other hand, can run up to 100,000 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 light source.

3. Invisible Light

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 more light output isn’t what you can actually see. An HID bulb, like a metal halide, generally wastes a significant amount of its energy consumption producing heat.

LED bulb technology, in general, produces very little heat and most of the energy consumed is used to produce light, which is the true purpose of lighting anyway.

4. 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 colors 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 a range of CRIs, so you can determine what is best for your facility’s needs and make the appropriate choice.

As you can see, there are many benefits of LED bulbs over HID bulbs, traditional incandescent light bulbs, 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 of 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 the 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 reality, commercial and industrial facilities won’t just replace a single light. In fact, many of these facilities have hundreds of lights that need replacing.

Getting the same brightness, you can save $353 a year by switching one light bulb to a LED light bulb, imagine how much you could save by switching hundreds of bulbs to LED.

However, as we said, savings on energy use with energy efficient lighting is 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.