LED High Bay Buying Guide for Warehouses: UFO vs. Linear, Wattage, and Mounting Height
High bays are the workhorse of warehouse lighting, but picking one means more than grabbing the highest wattage. The right fixture depends on how high your ceiling is, whether you have racking, and how the space is used. This guide covers the main choices.
What Counts as a High Bay?
High bay fixtures are made for ceilings around 20 feet and up. Below about 15–18 feet, LED shop lights or low bays are usually the better choice, since a high bay at that height can cause glare and hot spots.
UFO vs. Linear High Bays
| UFO (round) high bay | Linear high bay | |
|---|---|---|
| Shape and beam | Compact and round, with a focused beam | Long and rectangular, with a wider spread |
| Best for | Tall open areas, 25 ft and higher, and spot coverage | Aisles, racking, and 20–30 ft ceilings |
| Weight and install | Light, hook or pendant mount | Chain, cable, or surface mount |
| Glare | Higher at low heights | Lower, often with diffuser options |
| Heat | Fins pull heat from a compact body | Spread across a larger housing |
When to choose a UFO
Choose a UFO for open floors, distribution centers, manufacturing bays, and gyms with tall ceilings. Browse our UFO high bays.
When to choose a linear
Choose a linear fixture when you have rack aisles, where the long shape lights both sides of the aisle evenly. Linear fixtures also suit lower high bay ceilings where glare matters. Browse our linear high bays and 6G linear high bays.
Wattage and Lumens by Mounting Height
Use lumens, not watts, to size a fixture. This table is a starting point for general warehouse work at roughly 20–30 foot-candles:
| Mounting height | Typical lumens | Typical LED wattage |
|---|---|---|
| 15–20 ft | 10,000–20,000 | 80W–150W |
| 20–25 ft | 20,000–30,000 | 150W–200W |
| 25–35 ft | 30,000–45,000 | 200W–300W |
| 35–45 ft+ | 45,000–80,000 | 300W–500W |
For detailed tasks like assembly or inspection, step up a size or tighten the spacing. For bulk storage, you can go lighter. Our post on warehouse lighting by ceiling height goes deeper.
Spacing and Layout
- Open floors: space fixtures about 1 to 1.5 times the mounting height apart. At 25 feet, that's about 25–35 feet between fixtures.
- Rack aisles: center fixtures over the aisle, not over the racks. Linear fixtures run parallel to the aisle.
- Loading docks: add fixtures near the doors, where trucks and forklifts are working.
Selectable Wattage and CCT
Many of our high bays let you set the wattage and color temperature on site. That means one model can cover several areas, and you can adjust the output after installation. For example:
- LED UFO High Bay – 100W/120W/150W Selectable (up to 22,078 lumens, 120-277V) for 15–25 ft ceilings.
- High-Output LED UFO High Bay – 200W/240W/300W Selectable (up to 48,390 lumens, 120-277V) for 25–35 ft ceilings.
- Ultra High-Output LED UFO High Bay – 300W/400W/500W Selectable (up to 80,300 lumens, 120-277V) for very tall spaces.
- 4FT Linear High Bay – Selectable 80W–300W, 3500K/4000K/5000K (120–277V) for aisles and racking.
Voltage: 120-277V vs. 277-480V
Many warehouses run 277V or 480V lighting circuits. Check your panel before you order, because a 120-277V fixture can't go on a 480V circuit. We carry high-voltage options like the 277-480V UFO high bay and 277–480V linear high bay, and the full 480V lighting collection.
Controls and Sensors
0-10V dimming and occupancy sensors can cut energy use a lot in aisles that sit empty most of the day. Some of our linear high bays have a sensor base, so you can add a sensor later. Utilities often pay higher rebates for networked or sensor-controlled fixtures.
Special Environments
- Cold storage and washdown: vapor tight fixtures.
- Hazardous locations: explosion proof lighting.
- Federal projects: TAA compliant fixtures.
Certifications and Rebates
Look for UL or ETL safety listing and DLC listing on the product page. Certifications vary by model, and DLC listing is usually what qualifies a fixture for utility rebates. See our rebate and DLC guide.
Get Help Picking the Right Fixture
Steel Tech Lights has 17 years in commercial lighting, and every fixture we sell is backed by a 5-year warranty. Send us your layout, pole or ceiling height, and voltage, and we'll recommend fixtures and quantities. Call (888) 720-1137 or Get a Quote.
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