LED High Bay Buying Guide: UFO vs Linear, and the Specs That Decide It

LED High Bay Buying Guide: UFO vs Linear, and the Specs That Decide It

High bay lights cover the tall spaces: warehouses, manufacturing floors, gyms, hangars, and big-box retail, usually 15 to 40 feet to the ceiling. Pick the wrong lumen package or beam spread and you get dark aisles, hot spots, or a fixture that's too dim from 30 feet up. This guide walks the two main fixture types and the specs that actually decide the pick.

UFO vs linear: pick the shape to match the space

The two dominant high bay form factors solve different problems.

UFO high bays are round, compact fixtures (named for the saucer shape) that throw a wide, powerful cone of light. They're the default for open areas: warehouse floors, gymnasiums, and big open production space. They're easy to hang on a hook and chain, and they pack high lumen output into a small housing.

Linear high bays are long and rectangular. Their elongated shape lays light down evenly along a line, which makes them the better choice for aisles, racking, and assembly lines, anywhere you want uniform coverage down a row rather than a single bright pool. Many accept the same mounting and dimming options as UFOs.

Quick rule: open area, reach for a UFO; aisles and racking, reach for linear.

Buy by lumens, not watts

With LED, wattage no longer tells you brightness. Spec by lumens. As a rough orientation, modern LED high bays land around 130 to 180 lumens per watt, so a more efficient fixture hits the same lumens at lower wattage and lower operating cost. Use watts for your load calc and energy budget, and use lumens to size the light.

Typical lumen targets by mounting height (industry rules of thumb, not a code figure):

  • 10 to 15 ft: roughly 10,000 to 15,000 lumens
  • 15 to 20 ft: roughly 16,000 to 20,000 lumens
  • 25 to 35 ft: roughly 30,000+ lumens

A 15,000-lumen fixture that's fine at 20 feet will look dim at 30 feet, and a 30,000-lumen fixture mounted low can be glary. Match the package to the height. (For reading these numbers off a cut sheet, see our guide on how to read a lighting spec sheet.)

Mounting height and spacing

A simple rule for even light in open areas: space fixtures about as far apart as they're mounted high. Lights at 15 feet, space them roughly 15 feet apart. Don't push past about a 1.5:1 spacing-to-height ratio or you'll get shadows and dark patches between fixtures. For a real layout, a quick photometric plan is worth it, and it's something we can run from your floor plan.

Beam angle: match it to the height

Beam angle controls how the light spreads:

  • Lower mounting (about 12 to 20 ft): a wider beam (around 105 to 120 degrees) gives broad, even coverage.
  • Higher mounting (about 30 ft and up): a narrower beam concentrates the light so it still lands with intensity at the floor.

Many UFO high bays offer selectable or interchangeable optics so you can tune the beam to the height. Linear fixtures tend to give excellent uniformity at lower mounting heights where broad coverage helps safety and productivity.

Wattage, voltage, and dimming

  • Selectable wattage: many current high bays are field-selectable, so one SKU covers several wattage and lumen points. The Westgate UHX UFO line we stock, for example, switches between several wattages in one fixture.
  • Voltage: most high bays run on universal 120-277V; large industrial gear may use 480V.
  • Dimming and controls: look for 0-10V dimming so the fixture can pair with occupancy sensors and daylight controls. That's also how you meet commercial energy-code control rules. (See our explainer on 0-10V dimming.)

Color temperature, listings, and rebates

  • CCT: 4000K (neutral) and 5000K (cool, crisp) are the common warehouse and shop choices; many high bays are field-selectable between them.
  • DLC listing: matters for utility rebates. If you want rebate money, confirm the model is DLC listed (Standard or Premium).
  • IP rating: for dusty or damp spaces, check the IP rating; vapor-tight versions exist for wash-down and cold storage.
  • Rated life and warranty: high bays commonly carry long rated lives (often 50,000 to 100,000 hours) and multi-year warranties; confirm per model.

Buy high bays from Rock

Rock Lighting & Electric stocks UFO and linear high bays from authorized brands at contractor pricing, with nationwide shipping. We carry the field-selectable Westgate UHX UFO high bays (50W up to 230W, 0-10V dimmable, 4000K/5000K, 120-277V), RAB high bay and RAIL linear pendants, and Cooper Metalux. Browse the full high bay collection, and if you send us your floor plan and ceiling height we'll size the lumens, spacing, and optics and quote it. Contact us with the space.

FAQ

What's the difference between UFO and linear high bays?
UFO high bays are round and throw a wide cone of light, ideal for open areas like warehouse floors and gyms. Linear high bays are long and rectangular and lay light down evenly along a line, which makes them better for aisles, racking, and assembly lines.
How many lumens do I need for my ceiling height?
As a rule of thumb, about 10,000 to 15,000 lumens for 10 to 15 ft, 16,000 to 20,000 lumens for 15 to 20 ft, and 30,000+ lumens for 25 to 35 ft. Spec by lumens, not watts, and confirm with a layout for your specific space.
How far apart should high bay lights be spaced?
A good starting point is to space fixtures about as far apart as they are mounted high (a 1:1 ratio). Don't exceed roughly 1.5:1, or you'll get dark spots between fixtures.
What beam angle should a high bay have?
Use a wider beam (around 105 to 120 degrees) for lower mounting heights and broad coverage, and a narrower beam for high mounting (30 ft and up) so the light still lands with intensity at the floor.
Do high bay lights dim?
Many do, most commonly via 0-10V dimming, which also lets them work with occupancy sensors and daylight controls for energy-code compliance. Confirm the dimming protocol on the spec sheet.
Are LED high bays eligible for utility rebates?
Often, if the model is DLC listed. Check for a DLC Standard or Premium listing, and use the utility's rebate program or ask us to confirm eligibility for your model.

Lumen, spacing, and beam ranges above are general industry rules of thumb, not the rating of any specific product or a code requirement. Confirm the actual figures on the manufacturer's current spec sheet and run a layout for your space before ordering.

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