Warehouse lighting and visibility

Warehouse lighting is often seen only as an electricity bill: "too many lamps, a big bill". In fact poor light is a silent loss: an employee misreads a label, fails to notice a damaged carton, a driver sees someone stepping out from a corner too late. Such errors end up in the records as "shortage" or "wrongly picked order" and nobody remembers the cause. Below is how to judge lighting and how to improve it.

What lighting affects

• Errors. In a dark spot, in the small print of an article code, batch and expiry date, 3 and 8 or 1 and 7 are easily swapped. A barcode also scans slowly in poor light.
• Safety. A forklift driver sees a pedestrian late, and an employee sees an obstacle on the floor or an open hatch late, in a poorly lit place.
• Quality control. At receiving, a crushed corner under the film, a damp patch or a sign of a crack is visible in good light.
• Fatigue. Eye strain leads to headaches and lapses in attention, and older employees need more light.

Lighting standards are set according to the type of work and measured in lux. Get the exact value from a specialist; for a rough measurement an inexpensive lux meter or a phone app is enough.

Where light is lacking

The dark places are almost the same in every warehouse:

• the aisles between racks: lamps are often mounted above the racks, so the middle of the aisle and the lower levels stay in shadow;
• the inside of a truck body and the edge of the dock;
• corners, stairs and doorways, where the eye needs time to adjust moving from light to dark;
• the packing table and the place where labels are read, which need local lighting;
• night shifts and winter: there is no daylight, or it fades quickly.

Glare is a problem of its own: shiny film and laminated labels reflect the lamp, dazzle the eyes and confuse the scanner. Aim the lamp from the side rather than straight at the label.

How to improve it

1. Clean first. Fittings and roof windows coated with dust and grease cut the light noticeably. Washing twice a year gives a quick result.
2. Position lamps along the axis of the aisle, not above the racks. With tall racking, fittings hung above the aisle light the lower levels too.
3. Replace old lamps with LEDs. For example, if you swap 80 lamps of 400 watts for LEDs of 150 watts, you cut the load by 80 × 250 = 20 kilowatts. Run for 10 hours a day, 26 days a month, that saves roughly 5,200 kilowatt-hours a month. Multiply by your own tariff. LEDs switch on at once, work in the cold and last long, so there is less changing of lamps at height.
4. Fit motion sensors in rarely used aisles, but keep constant lighting over forklift routes so the sensor never lags.
5. Painting walls and floor a light colour raises brightness even without extra lamps.
6. Use natural light from roof windows, keep them clean and remember that in summer they add heat.

Visibility and safety

Lighting is only part of visibility. You also need reflective clothing for pedestrians and drivers, convex mirrors at the ends of aisles and at corners, and brightly contrasting barriers. The dock and the outdoor area need separate lighting in the evening and in winter. Autonomous (battery) lamps that show the escape route when the power fails should be tested regularly so that they work when needed; this ties in with fire safety as well.

How to check your lighting

Check lighting not at the height of the working day but at its weakest moment: in the evening or at the end of a cloudy day. Walk through the warehouse, stop in the middle of each aisle and try to read the label and barcode on the bottom level. Photograph it with a phone camera: if the label is hard to see in the picture, it is hard for human eyes too. Record the result in a table: place, condition, what to do. In particular compare the places with many incidents or picking errors; many of them will turn out to be dark.

Conclusion

Good light means fewer errors, more safety and faster work, and that saves far more than the electricity bill. During stock counts and audits, SkladKontrol marks the places where light is lacking and labels and barcodes cannot be read, and helps check whether counting and picking errors are piling up there.