LED Lighting Selection: Why LPW isn’t the Only Factor that Matters

As facilities strive to optimize operations, many are looking to industrial LED lighting as a solution to improve energy efficiency, reduce maintenance and provide a safer environment for employees. While LED fixtures have proven to deliver these benefits across a wide range of applications, including warehousing, transfer, storage and other material handling environments, there are many factors to consider in deciding which fixtures are right for your specific application.

Recently, there’s been a push by some LED lighting manufacturers to prioritize lumens per watt (LPW) as a key performance metric and compete on this criterion alone. While it’s certainly important—getting the most usable light per watt consumed is key to lighting efficiency—a high LPW often comes at a steep price, and not just in dollars and cents. Many buyers don’t realize that, in order to achieve the highest possible LPW, manufacturers must make significant sacrifices in other critical areas of lighting performance.

Much like you wouldn’t choose a new car based only on fuel economy, without also considering safety, durability, capacity and cost, choosing an industrial LED fixture based on LPW alone would be a big mistake. Here’s why.

The Trade-offs
In order to drive LPW higher, manufacturers may cut corners in other areas. These include:

  • Compromised LEDs & Electronic Components: To amplify LPW, manufacturers will often eliminate secondary optics or fixture lenses to eliminate obstacles that can lower lumen output. In a material handling environment, this exposes the fixture to greater risk of damage if struck by equipment or material, which often happens in the normal course of operations. The fixture is therefore less durable and at risk of greater failure and more frequent replacement. When LEDs are unprotected, airborne contaminants can attack LEDs and other electronic components and cause premature failure. In addition, poor thermal design and overheated LEDs can cause phosphor bleed and other issues such as lumen depreciation and color shifting.
  • Optical Control & Comfort: Pushing the lumen output higher and eliminating optics often turns high LPW LED fixtures into glare bombs that are hard on the eyes and make it difficult to see clearly. This discomfort makes it difficult to perform tasks, lowering productivity. And, in areas where material handling equipment and personnel are often moving about together, this creates a serious safety risk. It’s simply not worth it to gain a few more lumens per watt if it puts staff at risk. It also sacrifices optical control, which means the light is sprayed all over the place, even onto areas that don’t need illumination, wasting luminance on the walls, etc. Wasted light means wasted energy, which offsets the efficiencies gained by high LPW.
  • Color rendering: The near-daylight high CRI of LED lighting is one of its most attractive features for industrial applications, providing crisp, clear visibility, which enhances productivity, quality assurance and safety. But, to boost LPW, many manufacturers lower the CRI to save energy. This could leave workers struggling to distinguish colors on warning signs, wiring and other indicators that rely on color for communication. Here again, high LPW can mean a greater safety risk.
  • Fixture size: To maximize LPW, some manufacturers underdrive the LEDs, even cutting amperage in half, in some cases. To compensate, they’re forced to add more LEDs to the fixture to achieve the same output. This adds substantially to the fixture size, weight and cost. The fixture may run more efficiently, but it’s too large, too heavy and too expensive to meet the buyer’s needs.

All of these trade-offs add up to a fixture that’s predisposed to underperform in virtually every metric besides LPW. Instead of saving money, high LPW fixtures often end up costing more to operate and require more frequent replacement, lowering the total ROI and customer satisfaction.

The Metrics that Matter
In virtually every situation, a high LPW simply isn’t worth the setbacks, sacrifices and headaches. Rather than be lured into the high-LPW hype, buyers should instead consider the fixture as an entire system and choose one based on overall performance, longevity and quality.

When choosing an industrial LED fixture supplier, here are the metrics that really matter:
1) Reliability and longevity. One of the key benefits of high-performance industrial LED lighting is it can virtually eliminate lighting maintenance, putting an end to the hassle, cost and safety risk of bulb changes for up to 10 years in some cases. And, by removing secondary optics and skimping on cheap LEDs and other components, high LPW fixture manufacturers churn out products that are prone to premature failure. Instead of those trade-offs, choose a fixture brand that emphasizes reliability and longevity to get the most ROI.
2) Light quality, comfort and efficacy. Getting the right light in the right places to ensure visual clarity and comfort is essential in industrial applications, particularly in material handling environments where product and people often intermingle. A high LPW fixture with poor color rendering, uncomfortable glare and poor optics will make for a dissatisfying result. Choose a fixture that delivers on the efficiency, color, clarity and comfort that makes LED lighting technology so attractive.
3) Total cost of ownership. Choosing an LED fixture based on LPW alone may save you a few bucks in energy costs but may end up costing you more than it’s worth down the road. After all, a fixture that’s cheaper up front but costs more over the long haul is NOT a good investment. Instead, choose a fixture that meets the DesignLights Consortium (DLC) LPW standards for performance and efficiency, but also uses industrial-grade components, high-quality diodes and secondary optics that maximize usable light.

While LPW fixture efficiency is a factor worth considering, it shouldn’t be the ONLY factor. Sacrificing key LED benefits in the pursuit of high LPW will result in poor performance, frequent replacement and dissatisfaction. Choosing a high-quality LED fixture that delivers performance, quality and safety over a longer life span will mean a lower total cost of ownership and higher ROI and customer satisfaction.

Vishnu Shastry is an Optical Engineering Manager at Dialight.

Show More

Related Articles

Back to top button