Explosion Proof High Bay Lighting: Sizing LED High Bays for Hazardous Warehouses
High bays light the big indoor volumes of hazardous industry — solvent warehouses, chemical production halls, flour and grain facilities. Here is how to size them correctly the first time.
Where Explosion Proof High Bays Are Required
- Solvent & paint warehouses — vapour zones around storage and decanting
- Chemical and petrochemical production halls — process equipment indoors
- Flour mills, grain elevators, coal handling — combustible dust Zones 21/22
- Battery rooms and distilleries — hydrogen and ethanol vapour
Sizing by Mounting Height (200 lux floor target)
| Mounting height | Fixture | Approx. coverage per unit | Spacing |
|---|---|---|---|
| 8–10 m | 100–150 W LED | 25–30 m² | 7–8 m grid |
| 10–12 m | 150–200 W LED | 30–38 m² | 8–9 m grid |
| 12–15 m | 200–300 W LED | 35–45 m² | 9–11 m grid |
| 15 m+ | 300 W or twin arrays | by calculation | by calculation |
Keep spacing-to-height ratio ≤1.5 for uniformity ≥0.6; verify final layout with DIALux and IES files.
HB21: Flameproof LED High Bay Family
| Parameter | HB21 Series |
|---|---|
| Protection method | Ex db IIC T6/T5 Gb — flameproof |
| Zones | 1 / 21 (also suited to Zone 2/22 areas) |
| Power range | 15–300 W |
| Application | Hazardous warehouses, production halls, dust facilities |
| Companion products | FL7 floods, LO linear lights, BAJ52 emergency — one certificate portfolio |
Product page: HB21 Series explosion proof high bay lights (ATEX & IECEx, Zone 1/21).
LED vs HID: The Warehouse Numbers
| Item | 250 W HID high bay | 150 W Ex LED high bay |
|---|---|---|
| Energy @ 8,760 h, $0.12/kWh | $263/yr | $158/yr |
| Relamp interval | ~20,000 h (2.3 yr) | 100,000 h L70 (11+ yr) |
| Relamp cost per event | Lift + certified lamp + downtime | — |
| Instant restrike (after power dip) | No — HID cooldown 10–15 min | Yes |
| 10-year TCO delta | baseline | ≈40–50% lower |
Instant restrike matters more than buyers expect: after a trip in a hazardous hall, HID fixtures leave the area dark for up to 15 minutes — a safety incident window that LED eliminates.
Dust Zones Change the Rules
Combustible-dust areas (Zone 21/22) carry their own equipment suffixes (Db/Dc) and dust ingress ratings (IP6X mandatory — dust layer ignition is the failure mode). High bays in flour and coal facilities must be assessed for surface temperature under dust accumulation, not just clean-air T-class. When specifying for dust, state the dust layer thickness assumption in your RFQ.
Emergency coverage completes the design: hazardous warehouses need certified Ex emergency luminaires (such as the BAJ52 series) on separate circuits, sized to deliver at least 1 lux on escape routes for 90 minutes after mains failure. Where aisles are long and racking high, combining certified high bays for general lighting with linear Ex fittings along rack faces gives better vertical illuminance on stored goods labels — the detail that warehouse auditors notice first.
Frequently Asked Questions
What is an explosion proof high bay light?
An explosion proof high bay is a high-output luminaire for hazardous areas with mounting heights above ~8 m — certified Ex db (flameproof) for Zone 1/21 or Ex nR for Zone 2/22. It is used in chemical warehouses, solvent stores, flour mills and production halls where dusts or vapours create a classified atmosphere.
How many explosion proof high bay lights do I need?
For a 200 lux floor target: roughly one 150 W LED high bay per 25–30 m² at 8–10 m, or one 200–300 W unit per 35–45 m² at 10–14 m. Layout must be verified photometrically — spacing-to-mounting-height ratios of 1.2–1.5 keep uniformity above 0.6.
Do warehouses need Zone 1 or Zone 2 high bays?
It depends what is stored. Solvent and paint storage typically drives Zone 1 near drums and Zone 2 in the general volume; flour, grain and coal storage creates Zone 21/22 dust zones. Match the certificate to the classification drawing — most warehouse volume is Zone 2/22, making Ex nR the economical choice.
Can LED high bays replace HID in hazardous warehouses?
Yes, and the case is strongest indoors: 24/7 warehouses running 250–400 W HID convert to 150–200 W Ex-certified LED with equal or better lux, cutting energy roughly in half and eliminating relamping cycles at 10–15 m heights where each lamp change is a lift job in a classified area.
What is HB21?
HB21 is SEEKINGLED's flameproof (Ex db) LED high bay family covering 15–300 W for Zone 1 and Zone 21 areas, with matched optics for warehouse and production hall layouts and the same certificate portfolio as the FL7 flood range.
Get a Quote for Your Project
Send us your hazardous area classification (zone, gas group, temperature class) and target lux levels — our engineers will reply with a full lighting layout and FOB Shenzhen quotation within 24 hours.
Email: sales02@seekingled.com | Exporting to 70+ countries · 1,000,000+ units shipped per year
- About Us
- Products
- Explosion proof light
- Portable explosion proof lighting
- Explosion proof emergency light
- Explosion proof LED T8 tube
- Explosion proof Junction Box
- Explosion proof street light
- Service
- FAQ
- Docs download
Service hotline
Tel：+86 755 29846615
Work time：9:00-20:00
E-mail：sales02@seekingled.com
address：5F, Building 5, Guole Science and Technology Park, Lirong Road, Dalang Street, Longhua, Shenzhen, China