Industrial and commercial LED warehouse lighting are used to provide ambient lighting and task visibility in commercial and industrial storage facilities.
Warehouses are designed to provide an appropriate environment to store goods, materials and equipment that need to be protected from outdoor elements and may provide value-added services such as product mixing, light assembly, order fulfillment, cross-docking, packaging, etc.
Warehouse operations are the heart of the business. Warehouse lighting design is a key factor in maximizing productivity and minimizing errors and accidents in any facility.
An environment that can move goods and materials quickly and efficiently through storage areas, while keeping workers safe in the process, requires a lighting solution that supports visual performance and comfort.
At the same time, warehouse lighting is challenged to minimize cost and disruption in an environment with high, hard-to-reach ceilings and vast spaces, and may require lighting equipment to survive high or low temperatures, abnormal atmospheric conditions and long hours of operation.
Warehouses, and their various cousins, such as distribution centers, are very diverse in their applications. Warehouses can be classified by type, which is defined by building characteristics (architectural design, ceiling height, loading capacity, etc.).
The most common types of warehousing facilities include regional warehouses, bulk warehouses, heavy distribution warehouses, refrigerated distribution facilities and rack support facilities.
Regional warehouses, also referred to as local warehouses or office warehouses, are typically no larger than 100,000 square feet in size. These facilities lack manufacturing attributes and their primary function is to store goods.
Bulk warehouses are large storage facilities that can accommodate large volumes of goods and materials for periods of time ranging from extensive storage to almost immediate distribution.
These facilities have a minimum size of 100,000 square feet and a maximum size that can exceed 1,000,000 square feet. Bulk warehouses typically have ceiling heights in excess of 20 feet, often approaching 30 feet in newer buildings.
Manufacturing space is a small percentage of the building’s total floor area, rarely exceeding 10%.
Heavy distribution buildings or distribution centers share certain characteristics with bulk warehouses, but favor the function of distribution over storage.
These buildings have ceilings that reach or exceed 30 feet in height and have a minimum area of 100,000 square feet.
Both bulk warehouses and heavy distribution buildings have access to (mobile or fixed) shelving. Refrigerated distribution buildings are controlled atmosphere facilities equipped with refrigerated rooms (chillers) to store products at temperatures above 0°C (32°F) and frozen storage rooms (freezers) to store products at temperatures below 0°C (32°F).
The racked buildings offer the highest space efficiency thanks to the use of high-rise shelving that covers the entire space. These facilities have fully automated transport and retrieval systems that allow storage levels to rise above 100 feet.
As energy and labor costs rise, maintaining tight control over operating expenses is an essential part of warehouse management. Warehouses are energy-intensive buildings, huge in size, and operate 24/7. Every little bit of savings can add up and help the bottom line.
An inefficient facility can erode a company’s bottom line and put it at a competitive disadvantage. Traditional high bay lighting using HID and fluorescent technology is a drain on your resources.
Saying goodbye to these technologies isn’t just driven by inefficiencies at their source, but can be attributed in large part to the poor behavior of other components in the Lighting Application Efficiency (LAE) framework and the costly lighting maintenance associated with the use of HIDs and fluorescents.
The omnidirectional output of HID and fluorescent lamps makes it difficult to efficiently convert the emitted light into a more useful distribution. When HID and fluorescent lamps are installed in luminaires, their modest efficiency is immediately beaten by about 30%.
Traditional lighting solutions are susceptible to high frequency switching and are incompatible with advanced sensors and wireless controls.
The constant on/off operation and poor dimming performance of HID and fluorescent lights leaves facility managers with the dilemma of leaving these lights on 24 hours a day to maximize their life or turning them off to reduce energy use when there is no traffic or activity.
Some of the other issues were related to traditional warehouse lighting. The use of glass housings makes these lights vulnerable to mechanical shock or vibration. Housing failures (exploding bulbs) in metal halide lamps can even put workers and equipment at risk. Colder temperatures often stress fluorescent lamps, challenging their performance in cold storage.
Warehouses are jumping on the LED bandwagon to reap the benefits of solid-state lighting. With light source efficiencies of up to 150+ lm/W, full conversion to LED technology can cut energy use by more than half.
The ability to convert electrical energy to light energy through electroluminescence in a compact semiconductor package makes it possible to fully optimize all LAE factors for energy savings, not just improve light source efficiency.
The efficient delivery and effective distribution of light emitted by directional LEDs can be more easily achieved than with conventional light sources.
Optical efficiency, the ratio of light emitted by a luminaire to light emitted by a light source, is a key performance marker in luminaire design.
The use of precision-engineered, package-level secondary optics allows LED luminaires to achieve optical efficiencies in excess of 90% while providing the highly uniform light distribution that is critical to the performance and safety of facility users.
With instant-on, instant-restart and full-range dimming capabilities, LEDs provide the flexibility to deliver lighting on demand through dimming, occupancy control, daylight harvesting and/or time control.
Building networking and software-based intelligence into LED luminaires can extend the energy efficiency benefits of LED lighting. The integration of solid-state lighting with the Internet of Things not only improves lighting control, but also facilitates unprecedented data exchange between lighting and other building management systems.
The wide variation in building layouts and ceiling heights has led to a proliferation of warehouse lighting fixtures that have been created to be compatible and integrated into specific warehouse environments.
The clear height of new distribution centers and warehouses connected to manufacturing facilities has steadily increased over the years, from 24, 28, 32 and most recently 36 feet, due to the increasing demand for more cubic capacity for stacking and shelving.
As a result, industrial and commercial warehouse lighting fixtures typically fall under the category of high bay lights, which are designed for installation in buildings with clear heights exceeding 6.1 meters (20 feet).
The choice of luminaire configuration is primarily governed by the light distribution requirements.
In general, the color quality of the light source is not a priority in warehouse lighting design. It is usually the luminous efficiency and thermal performance that determine the choice of light source.
The color rendering index (CRI) of LEDs is typically in the 80, which is in the middle of the acceptable range for warehouse lighting applications.
In most cases, this level of color fidelity will meet the color discrimination requirements for warehouse lighting. Proper color representation and high color temperatures indicate a spectrum rich in blue wavelength energy, which contributes to visual acuity in the spectrum, which is important for object restoration when completing detail-oriented tasks.
Despite impressive improvements in energy efficiency compared to conventional light sources, LEDs currently convert less than 50% of the power supply into light and dissipate the rest as heat.
Heat is deposited in the LED package by conduction, rather than thermal radiation as in incandescent lamps.
In order to keep the critical junction temperature below a set limit at all times and under all operating conditions, the waste heat generated at the LED junction must be transferred to the ambient air by heat conduction and convection through all elements that make up the heat path.
Localized overheating due to inadequate thermal management will accelerate degradation of the chip and packaging materials, leading to lumen depreciation and shortened lifetime. Therefore, thermal management is one of the most important aspects of LED system design.
Effective thermal management requires a holistic approach that includes regulation of drive current, improved heat dissipation in the thermal path, and the use of thermally stable LEDs and electrical components.
A good optical design improves optical transmission efficiency, maximizes luminaire spacing, supports visual performance, and enhances visual comfort.
The focus of the optical design of a warehouse lighting system is usually to deliver and distribute light precisely and evenly to the intended area with minimal optical loss.
While uniform horizontal illumination is always a minimum requirement for high bay and low bay lighting applications, the importance of vertical illumination should not be overlooked.
In storage areas with shelving systems, providing high vertical illumination to quickly identify the contents of the shelves is a critical requirement.
Efforts should be made to illuminate all visual tasks that occur in the vertical plane, providing highly uniform illumination from top to bottom, along the entire length of the storage aisle.