LED high bay lights: a UK buyer's guide for warehouses and factories

Published 2026-11-01

LED high bay lights are the main light source in most UK warehouses, distribution centres and factories. Choosing the right one decides how well your aisles and floors are lit, how much electricity you use and how many fittings you hold as spares. This guide explains what to check before you buy: mounting height, the light level each zone needs, efficacy in lumens per watt, IP and IK ratings, beam angle, controls, and whether a round (UFO) or linear high bay suits the space. At the end you will find a comparison of the Polaris high bays, with the specifications from our published spec sheets.

The short answer

• Open floors, production halls and loading areas: a round (UFO) high bay with a wide beam, such as PS-UFO-MAX, switchable on site to 100, 150 or 200 W at 200 lm/W.
• Narrow racking aisles: a linear high bay with an aisle optic, such as PS-CURVE, which puts light on the floor and rack faces between the racks.
• Spaces where people look up, such as workshops and sports halls: a low glare high bay, such as PS-MILD with UGR below 19.
• Hazardous areas with flammable gas, vapour or combustible dust: an ATEX and IECEx certified high bay, such as PS-ATEX-HIGHBAY.
• In every case: compare the lumens and lm/W of the complete fitting, add sensors where zones are empty, and ask for a lighting design before you order.

1. Start with the building: mounting height and layout

The right high bay depends on the building more than on the catalogue. Before comparing fittings, record:

• Mounting height: the height at which the fittings will hang, usually the underside of the roof steel or the existing trunking.
• Layout: open floor, racking aisles, picking areas, marshalling zones and loading bays.
• Racking height and aisle width, because these decide the optic.
• Existing lighting: type, wattage, number of fittings and hours of use.
• How the site works: shift patterns, and which zones stay empty for long periods.

Mounting height affects both output and beam. The higher a fitting hangs, the more its light spreads before it reaches the floor, so higher buildings generally need more lumens per fitting or a tighter beam to keep light on the working plane. Lower buildings can use less output per fitting, often with a wider beam for even light between fittings. There is no reliable rule of thumb that turns a ceiling height into a wattage. The answer comes from a lighting calculation that takes the height, the spacing, the room surfaces and the target lux into account.

This is why PS-UFO-MAX is switchable. A DIP switch sets each fitting to 100, 150 or 200 W on site, so one product code covers different mounting heights and light levels, and the output can be matched to the lighting design zone by zone.

2. Set the target light level for each zone

Light levels for UK workplaces are set out in BS EN 12464-1:2021, Light and lighting. Lighting of work places. Indoor work places. The maintained illuminance values for warehouse areas include:

Two points are often missed. First, these are maintained values: the level the installation must still deliver as the fittings age and get dirty, not the level on the first day. Second, racking aisles need vertical light on the rack faces as well as light on the floor, so that pickers and truck drivers can read labels at every level. Our guide to racking aisle lux levels covers this in more detail.

Designing to the right level for each zone also saves energy, because you are not paying to over-light bulk storage.

3. Compare efficacy in lumens per watt

Watts tell you what a fitting uses. Lumens tell you how much light it gives. The ratio between them, lumens per watt (lm/W), is the best single measure of efficiency.

PS-UFO-MAX gives 40,000 lumens at 200 W, which is 200 lm/W. For the same light, a fitting with a lower efficacy has to draw more power every hour it is on. When you compare quotes:

• ask for the lumen output of the complete fitting, not of the LED chip, because the optic and driver lose some light;
• ask for the lm/W at the wattage you will actually run;
• check that the figures come from test data, for example LM-79 for the fitting and LM-80 and TM-21 for lumen maintenance.

Read more in why lumens per watt matters.

4. Check the IP and IK ratings

The IP rating (IEC 60529) describes protection against dust and water. The first digit covers solids and the second covers water. IP65 means dust-tight and protected against water jets, which suits most warehouses, factories and covered loading areas. PS-UFO-MAX, PS-MILD and PS-ATEX-HIGHBAY are all IP65.

For washdown areas in food processing, cold rooms and livestock buildings, a high bay is not always the right fitting. A sealed batten rated IP69K, such as PS-CORROSION, is designed for high pressure cleaning.

The IK rating (IEC 62262) describes resistance to impact. IK08 is rated for 5 joules and IK10 for 20 joules. In areas where fittings could be hit, for example in sports halls or near forklift masts, a higher IK rating is worth having. PS-UFO-MAX is IK08, while PS-MILD and PS-ATEX-HIGHBAY are IK10.

Check the operating temperature too if the site includes cold stores or hot process areas. PS-UFO-MAX is rated from -40°C to +60°C.

5. Choose the beam angle and optic

The beam angle decides where the light lands.

• A wide beam, such as the 90° beam on PS-UFO-MAX, gives even light over open floor areas, production halls and marshalling zones.
• An aisle optic, such as the 30 x 90° lens on PS-CURVE, throws light along a narrow aisle and onto the rack faces, rather than onto the top of the racking. PS-CURVE also has a 60 x 110° optic for logistics floors and a 90 x 110° optic for open workshops.
• Where glare matters, the unified glare rating (UGR) is as important as the beam. PS-MILD keeps UGR below 19 for spaces where people look up.

Mixing optics in one building is normal: aisle optics in the racking and wide beams in the open areas.

6. Add controls and sensors

In most warehouses some aisles and zones are empty for much of the shift. Sensors dim or switch fittings when nobody is there or when there is enough daylight, and LED high bays return to full output immediately when someone arrives.

• PS-UFO-MAX takes a plug-in PIR and daylight sensor, or a plug-in microwave and daylight sensor, that fits into the port under the fitting in seconds with no rewiring. Settings can be adjusted with an optional handheld remote.
• PS-CURVE supports 1-10V and DALI dimming for connection to a lighting control system.

How much controls save depends on how each zone is used, so we look at occupancy and daylight during the survey rather than assume a figure.

7. UFO or linear high bay?

Many sites use both: UFO high bays over the open areas and linear high bays in the racking.

8. Check lifetime, build quality and warranty

Look for a stated lifetime to a recognised method. L80B10 >50,000 h (TM-21), as stated for PS-UFO-MAX, means that after 50,000 hours the fittings are projected to give at least 80% of their initial light, with no more than 10% of fittings falling below that level. TM-21 is the method used to project lumen maintenance from LM-80 test data.

Ask which LEDs and which driver are inside. The LEDs and the driver decide how efficient a fitting is and how long it lasts, so a named component maker is a useful quality check. PS-UFO-MAX uses Lumileds LEDs with a Sosen driver (driver efficiency above 93%).

Also check surge protection, driver protection and power factor. PS-UFO-MAX has 4 kV surge protection, OTP, OCP, OVP and SCP driver protection, and a power factor above 0.95.

Finally, check the warranty and who stands behind it. Every Polaris product carries a 5-year warranty, and we survey, design, supply and install, so one team is responsible from the first visit to aftercare.

9. Work out the payback

The energy saving from an LED upgrade comes from three numbers: the wattage saved per fitting, the number of fittings and the hours the lights are on each year.

Energy saved (kWh a year) = fittings x watts saved x hours / 1,000. Multiply by your electricity unit rate for the cost saving. Simple payback in years = project cost / annual cost saving.

Our LED savings calculator does this with your own fittings, hours and tariff, and our guide to LED high bay upgrade costs and savings works through an example. For reference, these are results from our published warehouse projects:

Savings depend on the existing lighting, hours of use and energy prices on each site. See more on our projects page.

Polaris LED high bay lights compared

All figures below are taken from the Polaris spec sheets and product pages. Where a value is not yet published, we show "on request" rather than an estimate.

Source: Polaris Light spec sheets and product pages, October 2026. On a phone, scroll the table sideways.

Every Polaris high bay carries a 5-year warranty. Download the spec sheets from each product page, or ask us for photometric data for your lighting design.

Next step: a lighting design for your building

The fastest way to the right high bay is a survey and a lighting design. We record the mounting heights, layout and existing fittings, design to BS EN 12464-1 for each zone, and come back with the fittings, the light levels and the energy saving per zone. See how an LED high bay installation runs, or contact us to book a survey.

Sources

• BS EN 12464-1:2021, Light and lighting. Lighting of work places. Part 1: Indoor work places (BSI).
• IEC 60529, Degrees of protection provided by enclosures (IP code).
• IEC 62262, Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code).
• Polaris Light spec sheets for PS-UFO-MAX, PS-CURVE, PS-MILD and PS-ATEX-HIGHBAY, October 2026.

Frequently asked questions