High Bay Lighting Buying Guide: Mounting Height, Lumens, Beam Angles & Layout
High bay lighting is specified around mounting height, delivered illuminance at the task plane, optical control, and layout discipline. In warehouses, manufacturing, gyms, and distribution centers, the most common performance failures trace back to mismatched lumen packages, beam distributions, and spacing — not fixture quantity.
This buying guide covers UFO and linear high bays, lumen-package selection, beam control, spacing strategy, and controls planning so systems commission cleanly and maintain consistent visibility across aisles, open floor areas, and critical task zones.
Most high-bay problems emerge after commissioning: glare complaints, shadows between rows, uneven floor illuminance, and weak vertical brightness at racks, equipment, or pedestrian paths. High bay layouts should be treated as an engineered lighting system, not a wattage substitution.
High Bay Specification Reality Check
- Wattage is not a lighting metric. Delivered illuminance and uniformity at the task plane are the outcomes that matter.
- Mounting height drives selection. Lumen package and distribution must match height and the intended spacing pattern.
- Uniformity is a safety input. Poor spacing creates shadows, hot spots, and avoidable visual fatigue.
For selection methodology that applies across fixture families (including code alignment and performance standards), reference the commercial lighting specification guide hub. If your project is below typical high-bay mounting heights and uses grid or architectural ceilings, the commercial ceiling lighting selection guide provides the correct framework.
Last reviewed: January 2026 · Updated for current high-bay layout practices, photometric planning workflows, and controls commissioning considerations.
In this guide
Start With the 3 High Bay Lighting Truths
- Mounting height sets the baseline. A 15-foot install and a 40-foot install require different distributions, spacing, and lumen packages to produce usable light at the floor and on vertical planes.
- Beam control determines usability. The wrong distribution creates glare and hot spots, or leaves dark zones between rows and at aisle transitions.
- Uniformity supports operations. Consistent illumination improves wayfinding, forklift movement, pick accuracy, and reduces eye strain in long-shift environments.
High Bay vs Low Bay: Defined by Mounting Height
- Low bay lighting: typically mounted below ~20 ft
- High bay lighting: typically mounted ~20–45+ ft
Using low-bay distributions at high-bay heights commonly produces weak task-plane illuminance and poor uniformity. Using narrow high-bay distributions at lower mounting heights can increase discomfort glare and create high source brightness in normal viewing angles. Height classification should be confirmed from actual field conditions, not plan assumptions.
Mounting Height and Lumen Requirements
Mounting height influences beam footprint at the floor, spacing limits, and the lumen package required to reach target footcandles. Published lumens are only useful when paired with a spacing strategy or a validated photometric layout for the specific geometry of the space.
| Mounting Height | Typical Lumen Range | Common Applications |
|---|---|---|
| 15–20 ft | 15,000–20,000 lm | Gyms, workshops, light industrial, small warehouses |
| 20–30 ft | 20,000–30,000 lm | Warehouses, production floors, distribution staging |
| 30–45+ ft | 30,000–40,000+ lm | Large distribution centers, high-rack storage, specialized industrial |
These ranges are a starting point. Results should be confirmed with point-by-point photometrics in the conditions that drive failure: racking aisles, end-of-aisle transitions, pick faces, mezzanines, and mixed-height zones. For adjacent exterior coverage (dock aprons, loading lanes, perimeter doors), use the commercial site lighting planning guide.
Beam Angle Selection
Beam distribution determines whether delivered light reaches the task plane efficiently and whether the fixture creates objectionable brightness in typical viewing angles.
- 60°: higher ceilings, taller racks, narrow aisles, or locations requiring tighter control
- 90°: general-purpose warehouse and manufacturing layouts with moderate spacing
- 120°: lower mounting heights or wide open areas where broader distribution supports uniformity
Distribution selection must be made with mounting height and spacing together. When spacing exceeds the optic’s effective footprint, uniformity degrades quickly and layouts become sensitive to minor mounting variance, aiming differences, and reflectance changes.
UFO vs Linear High Bays
UFO and linear high bays can both succeed, but their best-fit layouts differ based on distribution geometry and how the space is organized.
- UFO high bays: common in open floor plans and retrofits; compact form factor; best when distribution is matched to height and spacing intent.
- Linear high bays: typically provide stronger directional control; often used to support aisle and rack strategies where longitudinal distribution and uniformity matter.
Related Technical Guidance
Spacing, Uniformity, and Layout
Spacing decisions control uniformity, glare perception, and the likelihood of shadowing around racks and equipment.
A practical starting point is spacing no greater than ~1.0–1.5× mounting height, then refining based on distribution, lumen package, reflectances, and obstruction geometry. Layouts should be validated where problems show up: long aisles, end-of-aisle transitions, pick modules, cross-traffic lanes, and pedestrian paths. Where moisture, dust, or washdown exposure exists in back-of-house areas, fixture selection may shift to sealed linear systems; use the vapor-tight sealing and exposure guide when the environment drives the decision.
Controls, Sensors, and Commissioning
Controls reduce operating cost only when zoning and coverage are planned with the layout and workflow. High-bay controls failures typically come from sensor coverage gaps, zoning that does not match movement patterns, and dimming behavior that is inconsistent across fixtures.
- Occupancy strategies: apply by aisle or zone to avoid full-bay switching and nuisance cycling.
- High-mount sensors: specify sensor types appropriate for height and the motion profile of the space.
- Daylight response: useful near skylights and perimeter glazing when zones are separated and minimum safety levels are maintained.
Plan control intent before ordering fixtures, then commission against that intent. If egress paths, stair towers, or life-safety minimum illumination are part of the scope, coordinate with the exit and emergency lighting compliance guide so control strategies do not conflict with required illumination during outages.
Common High Bay Lighting Failures
- Glare complaints caused by overly narrow distributions or high source brightness at lower mounting heights
- Under-lighting caused by insufficient lumen package at actual field height
- Dark zones between fixtures driven by spacing beyond the optic’s effective footprint
- Weak aisle visibility caused by distributions that do not support rack faces and vertical planes
- Controls failures including nuisance switching, inconsistent dimming behavior, or zoning that does not match workflow
High Bay Lighting Specification Checklist
| Spec Item | Why It Matters |
|---|---|
| Mounting height (actual field condition) | Sets the baseline for lumen package, distribution choice, and spacing limits. |
| Target illuminance and task-plane definition | Prevents over-lighting or under-lighting and stabilizes results across zones. |
| Lumen package selection | Determines delivered levels when paired with the chosen distribution and spacing. |
| Distribution / beam control | Controls glare, footprint size, and uniformity between rows and at transitions. |
| Spacing strategy and validation method | Reduces dark zones and supports predictable uniformity in aisles and open areas. |
| Controls and zoning intent | Ensures sensors and dimming align with workflow, safety minimums, and commissioning. |
Shop High Bay Lighting
High bay lighting should be planned using mounting height, distribution control, spacing discipline, and a defined controls strategy. When these inputs are set early and validated where needed with photometrics, facilities avoid glare complaints, shadowing, and uneven illumination across the life of the installation.
High Bay Lighting — Technical FAQs
What is the most important input when specifying high bay lighting?
Mounting height. Height determines the distribution footprint, spacing limits, and the lumen package required to deliver usable illuminance at the task plane. Many failures come from selecting lumen output without validating distribution and spacing for the actual height.
How do I decide between 60°, 90°, and 120° distributions?
Select distribution based on height and layout geometry. Narrower distributions are used to control spill and reach the task plane at higher mounting heights or tighter aisles. Wider distributions can support uniformity at lower heights or open areas when spacing is within the optic’s effective footprint.
Why do high bay retrofits often look bright but still perform poorly?
Brightness perception can be misleading. Layout failures typically show up as shadows between rows, weak vertical illumination at racks and equipment, and high-angle glare. These issues are usually caused by spacing and optic mismatch rather than fixture quantity.
When should a project use linear high bays instead of UFO high bays?
Linear high bays are commonly chosen when aisle control, longitudinal distribution, and uniformity at rack faces matter. UFO fixtures can perform well in open layouts or retrofit conditions when distribution and spacing are matched to mounting height and the intended coverage pattern.
What spacing rule is most reliable for early layout planning?
Use spacing that stays within the effective footprint of the selected distribution. A common early planning approach is spacing within roughly 1.0 to 1.5 times mounting height, then refining based on photometrics, reflectances, obstructions, and the priority zones that typically drive failure.
What causes glare complaints in high bay installations?
Glare is usually created by high source luminance in typical viewing angles, narrow distributions used at lower mounting heights, or layouts that place peak intensity in pedestrian and forklift sightlines. Glare control is typically addressed through distribution selection, mounting height validation, and spacing discipline.
How should controls be integrated into a high bay specification?
Controls should be planned by zone based on movement patterns, sensor coverage at height, and required minimum illumination. Commissioning should document sensor settings and dimming behavior so the system maintains consistent operation after turnover.