Buyers Guide to LED Low Bays

What are Low Bays?

Low Bay fixtures are commonly used as primary illumination for indoor commercial spaces with relatively low mounting heights, often around 10 to 20 feet. Typical applications include retail stores, small warehouses, workshops, and manufacturing areas where the fixture’s light distribution can provide appropriate coverage at lower mounting heights. Low bay fixtures are often available with wider distributions than high bay products, but beam angle alone does not determine performance; fixture optics, lumen output, mounting height, room geometry, and target light levels all affect the finished result.

LED low bays can provide high luminaire efficacy, with many current products delivering approximately 100 to 200 lumens per watt, depending on model, output, optics, color temperature, and other options. Compared with older fluorescent or HID systems, an appropriately designed LED upgrade can reduce energy use and maintenance requirements. Actual savings depend on the existing system, operating hours, controls, electricity rate, light-level requirements, and selected fixtures. The U.S. Department of Energy provides information on commercial-building energy efficiency and LED lighting at its Commercial Buildings Integration resources.

What are Low Bay LED Lights?

Low bay LED lights use solid-state light sources in fixtures designed for lower mounting heights. Unlike many legacy fluorescent and HID systems, LED fixtures do not use replaceable lamps or traditional ballasts. However, they are not maintenance-free: drivers, controls, seals, lenses, wiring, and other components may require inspection, cleaning, repair, or replacement over the life of the installation.

• Potential energy savings versus legacy fluorescent or HID systems, depending on the existing equipment and operating conditions
• Lumen outputs that can exceed 20,000 lumens on selected compact fixtures
• Reduced relamping and ballast-maintenance needs compared with many traditional systems

Payback periods vary by energy rate, operating schedule, installation cost, rebates, controls, and the existing lighting system. Multiple mounting configurations – including pendant, surface mount, and chain suspension – are available depending on the fixture model and installation requirements.

What’s the Difference Between Low Bay Lights and High Bay Lights?

Low bay and LED high bay lights for commercial spaces can serve similar commercial and industrial applications, but they are not simply the same fixture at different wattages. Product design, light distribution, output, glare control, mounting options, environmental ratings, and intended mounting-height ranges can differ.

• Low bay fixtures are generally selected for lower mounting heights and may use wider or more diffuse distributions.
• High bay fixtures are commonly selected for greater mounting heights and may use distributions designed to direct light farther to the work plane.
• The correct choice should be based on fixture-specific photometric data, mounting height, target foot-candles, uniformity, glare considerations, and the physical layout of the space.

Calculating the Number of Lights You Need

Determining fixture quantity requires more than a lumen estimate. A proper lighting plan considers space dimensions, mounting height, work-plane location, target foot-candle levels, fixture photometric data, surface reflectances, obstructions, and desired uniformity. For instance, a 5,000 square foot warehouse targeting 30 foot-candles at the work plane may require very different fixture quantities depending on mounting height, fixture output, optics, layout, and reflectances.

A photometric plan can show average and minimum illuminance, uniformity, light levels near walls and aisles, and potential glare concerns. Without this analysis, a layout may over-light some areas while leaving others inadequately illuminated. Lighting professionals often use guidance from the Illuminating Engineering Society (IES) along with project-specific requirements to establish appropriate illuminance and uniformity targets. LED Lighting Supply can prepare a complimentary photometric lighting plan using fixture-specific IES data and application information supplied by the customer.

How Much Light Do You Need?

Light-level requirements should drive the lighting design. Starting with wattage alone can result in inadequate or excessive illumination because wattage does not indicate where light is delivered. Professional lighting design begins with target foot-candle or lux levels at the relevant work plane, then uses fixture photometry to determine appropriate lumen output, mounting height, spacing, and layout.

Fixtures installed at greater heights will generally require more output or a different distribution to achieve the same work-plane illuminance, but there is no universal lumen-per-fixture rule for a given mounting height. For example, fixtures producing approximately 7,500 to 12,000 lumens may be suitable for some 10-to-15-foot applications, while fixtures producing 12,000 to 20,000 lumens may be suitable for some 15-to-20-foot applications. The appropriate output must be verified for the specific fixture and layout.

Spacing should not be based solely on a 1:1 mounting-height ratio. Fixture spacing depends on the optical distribution, delivered lumen output, mounting height, room dimensions, reflectances, obstructions, target illuminance, and uniformity requirements. Use fixture-specific IES files and a photometric layout to establish spacing and identify potential scalloping, dark areas, or glare.

How Many Foot Candles Do You Need?

Appropriate illumination varies by task, occupancy, visual difficulty, contrast, age of occupants, and applicable project requirements. As general starting points, some storage areas may use around 10 to 30 foot-candles, general work areas may use approximately 30 to 50 foot-candles, and detailed inspection or precision tasks may require 50 foot-candles or more. These are design references rather than universal code requirements; confirm the target level with the project owner, designer, insurer, AHJ, and applicable IES guidance where appropriate.

For construction work, OSHA illumination requirements are addressed in 29 CFR 1926.56. Permanent workplace lighting needs may also be governed by applicable building, electrical, safety, or local requirements.

What are the Different Types of Low Bays?

Low bay fixtures are available in several common form factors, each offering different mounting options, distributions, outputs, and aesthetics. Selection should be based on the specific fixture specifications and photometric performance rather than fixture shape alone.

UFO Low Bays

Round, compact fixtures commonly used in open areas where pendant or hook mounting is suitable. Depending on the model, they may be available with different reflectors, lenses, beam distributions, outputs, and environmental ratings. LED UFO low bays can be suitable for many applications within approximately 12 to 20 feet, but actual suitability should be confirmed with a photometric plan and the manufacturer’s mounting guidance.

Linear Low Bays

Linear fixtures often resemble traditional fluorescent strip or industrial fixtures and are commonly selected for aisles, assembly areas, retail spaces, and retrofit projects. LED Linear low bay fixtures are available in different lengths, outputs, distributions, mounting methods, and control options. Some models support continuous-row installations or compatible linking accessories; verify the exact product specification before planning a run.

Surface Mount Low Bays

Surface-mounted fixtures attach directly to a ceiling or mounting surface and can help preserve headroom where suspended fixtures are impractical. They may be useful around overhead doors, cranes, architectural features, or low ceilings. Installation must use a mounting method and electrical box or structure rated for the fixture’s weight and configuration. Surface-mounted fixtures can be effective at lower mounting heights, but glare and illumination should be evaluated using the selected fixture’s photometric data.

4. Understanding the Efficiency of LED Lights

LED luminaire efficacy, measured in lumens per watt, helps compare how efficiently fixtures convert electrical power into light. Many LED low bays fall within approximately 100 to 200 lumens per watt, depending on output, optics, CCT, CRI, driver configuration, and product design. Higher efficacy can provide more lumens for a given wattage, but it does not by itself guarantee better work-plane lighting, glare control, color rendering, or uniformity.

A 100-watt fixture can produce more total lumens than a less efficient 150-watt fixture, but the delivered light level in a space also depends on optics and layout. Evaluate published lumens, luminaire efficacy, photometric files, warranty terms, controls, environmental suitability, and expected operating conditions – not wattage or purchase price alone.

5. Do You Need Wet-location Fixtures?

Environmental protection requirements depend on the actual installation location and exposure. A fixture intended for a damp or wet location should be listed or rated by the manufacturer for that use and installed according to its instructions. IP ratings describe enclosure protection against ingress of solids and water, but they do not establish chemical resistance, corrosion resistance, sanitation suitability, or hazardous-location approval.

For example, IP65 indicates dust-tight protection and protection against water jets; IP66 indicates dust-tight protection and protection against powerful water jets; IP67 addresses temporary immersion under defined test conditions; and IP69/IP69K relates to high-pressure, high-temperature water-jet testing under the applicable standard. The required rating depends on the actual exposure, not a universal minimum. For washdown, chemical, salt-air, chlorine, or corrosive environments, also verify fixture materials, coatings, gaskets, hardware, and manufacturer environmental documentation.

A wet-location, vapor-tight, waterproof, or IP-rated fixture is not automatically approved for a hazardous location. Where a space has an established hazardous-area classification, the fixture’s exact Class, Division or Zone, Group, temperature rating, ambient rating, and certification must match the documented classification. LED Lighting Supply can help compare fixture specifications to an established classification but does not establish hazardous-area classifications.

Some fixtures are certified by a Nationally Recognized Testing Laboratory (NRTL), such as UL Solutions or Intertek/ETL, for applicable electrical-safety requirements. UL and DLC address different matters: UL certification may address product safety requirements, while DLC qualification is an efficiency and performance program and is not an electrical-safety certification. DLC qualification and rebate availability vary by exact model and local utility program.

Multi-Tap Drivers and Input Voltage

Input-voltage capability varies by fixture and driver. Many LED fixtures use universal-voltage drivers, such as 120-277V or 100-277V, that operate across the listed range without manual voltage selection. Other products use multi-tap drivers with specific selectable input-voltage taps, or they may require a separate high-voltage driver option.

Drivers rated for ranges such as 277-480V or 347-480V are available on selected models for compatible electrical systems. Higher distribution voltage can affect circuit design and conductor sizing, but allowable circuit loading, wire runs, overcurrent protection, voltage drop, and installation requirements must be determined by the qualified electrical professional in accordance with applicable code and the fixture instructions. Always verify the exact driver voltage range before ordering or installation.

Choose the Right Color Temperature

Color temperature, measured in Kelvin (K), describes the apparent warm-to-cool appearance of white light. It does not indicate brightness, color-rendering quality, efficacy, productivity, or glare. Lower CCTs generally appear warmer or more yellowish, while higher CCTs generally appear cooler or bluer.

• 4000K – Often described as neutral white and commonly used in commercial interiors
• 5000K – A cooler white appearance commonly selected for industrial, warehouse, and task-oriented spaces

The preferred CCT depends on the application, finishes, visual preferences, task requirements, and existing lighting. Color accuracy is evaluated separately through CRI and, where needed, more detailed color-quality metrics. Some surface-mount fixtures include onboard CCT selection switches, but this feature is model-specific and should be verified before purchase.

Understanding the Color Rendering Index When Selecting Low Bay Lights

Color Rendering Index (CRI) indicates how faithfully a light source renders colors compared with an appropriate reference illuminant of similar color temperature. CRI is separate from lumen output, CCT, and efficacy. It is especially relevant where workers need to distinguish colors, assess finishes, inspect products, or evaluate materials.

High-pressure sodium lamps often have poor color-rendering performance, while many commercial LED fixtures are available in CRI 70, 80, or higher options. A CRI around 70 may be appropriate for many general industrial applications, while color-sensitive tasks may benefit from 80 CRI or higher. The appropriate CRI depends on the task and project requirements.

Motion Sensors Work Well with Low Bay Lights

Occupancy sensors and other lighting controls can reduce energy use by dimming or switching compatible fixtures when areas are unoccupied. Performance depends on the selected sensor technology, sensor location, mounting height, coverage pattern, activity level, time-delay settings, daylight availability, and fixture-driver compatibility.

Some systems use 0-10V dimming, while others use integrated sensors, networked controls, relay switching, DALI, or other control methods. Not every low bay fixture is dimmable or sensor-compatible. Verify the driver, sensor, wiring method, control protocol, and commissioning requirements for the exact fixture. Proper placement and setup help avoid missed detection, nuisance operation, and excessive switching.

Expert Support Beyond the Sale

Our product specialists can prepare project-specific energy and cost-savings estimates using the available information about your existing lighting, proposed fixtures, operating schedule, electricity rate, and controls. These estimates can help support a business case for an LED upgrade, but actual results may vary based on installation and operating conditions. We can also help identify potentially applicable rebate programs and product qualifications; final eligibility, incentive amounts, and program requirements are determined by the utility or rebate administrator.

Our team can help review fixture specifications, beam distributions, driver compatibility, and photometric performance for commercial LED conversion projects. When you call LED Lighting Supply, you speak with lighting professionals who can help compare product options and answer application questions based on published manufacturer data and project information.