Project: LHC Lommel – LED high bays

Steel company LHC in Lommel (Belgium) replaced 40 mercury vapour lamps of 400W in its 4,000 m² production hall with 40 LED high bays 150W. The light on the work floor doubled from 150 to 300 lux, while the power for lighting dropped by 62.5%.

Project facts

Client	LHC, steel production
Location	Lommel, Belgium
Building	Production hall, approx. 4,000 m²
Completed	2023
Old lighting	40 × 400W mercury vapour
New lighting	40 × LED high bay 150W
Mounting	8 m, suspended on chains
Control	Dimmable
Illuminance	150 lux before, 300 lux after
Planning	DIALux light study

The starting point

LHC processes steel in a production hall of around 4,000 m², with machines, profile storage and overhead cranes running through the hall. The hall was lit by 40 mercury vapour lamps of 400W each, mounted at 8 m: a total of 16,000W.

Too dark for production work

With around 150 lux on the floor, the light level was too low for machining, measuring and handling steel safely. For workshop and production areas, around 300 lux is the usual target (see how much lux do you need).

High consumption

16,000W running 2,800 hours a year adds up to 44,800 kWh: more than €14,000 a year for lighting alone at €0.32/kWh. On top of that, mercury vapour lamps have been phased out in the EU since 2015, so replacement lamps were becoming hard to find.

The solution

Light study first

Before ordering, we made a DIALux light study of the hall. It showed that every old fitting could be replaced one for one by an LED high bay, while doubling the light level on the work floor.

40 LED high bays 150W at 8 m

All 40 positions now carry an LED high bay, suspended on chains at 8 m above the work floor and crane runways. The luminaire can be set to 90W, 120W or 150W; here it runs at 150W. With 210 lm/W and a 90° beam, it puts the light where the work happens. The high bays are dimmable, so the level can be lowered in zones that need less light. IP65 keeps out the dust that steel processing produces. More on choosing wattage and beam in our LED high bay guide.

LED luminaires used in this project

Energy savings in figures

	Before	After	Difference
Luminaires	40 × 400W mercury vapour	40 × 150W LED high bay	one for one
Connected load	16,000W	6,000W	−62.5%
Load per m²	4.0W/m²	1.5W/m²	−2.5W/m²
Consumption per year	44,800 kWh	16,800 kWh	−28,000 kWh
Electricity cost per year	€14,336	€5,376	−€8,960
CO2 per year	6.7 t	2.5 t	−4.2 t
Average illuminance	150 lux	300 lux	+100%

How we calculated this

• Before: 40 × 400W = 16,000W × 2,800 h = 44,800 kWh per year.
• After: 40 × 150W = 6,000W × 2,800 h = 16,800 kWh per year.
• Cost: 28,000 kWh × €0.32/kWh = €8,960 per year.
• CO2: 28,000 kWh × 0.15 kg/kWh = 4.2 t per year.

Ballast losses of the old mercury vapour lamps are not counted, so the real saving was even higher.

Investment and payback

At current webshop prices, the 40 LED high bays cost €3,210. Half of the investment was covered by an energy-efficiency subsidy, leaving €1,605. With €8,960 saved per year, the luminaires paid for themselves in about two months. Installation is not included in that figure; even with installation, a relighting with savings like these typically pays for itself within the first year.

Calculate the savings for your hall

The calculator below is pre-filled with the LHC figures. Change the values to see what a switch to LED would save in your own building.

The result

• Twice the light: from 150 to 300 lux on the work floor, the right level for production work.
• 62.5% less power: 6,000W instead of 16,000W for the same 40 light points.
• Instant full light: no warm-up time as with mercury vapour lamps, and no flickering near rotating machines.
• Lower running costs: €8,960 less on electricity every year and 4.2 tonnes less CO2.

Frequently asked questions

Can a 150W LED high bay replace a 400W mercury vapour lamp?

Yes. A mercury vapour lamp produces only around 50 lm/W, and part of that light is lost in the reflector. An LED high bay at 210 lm/W sends its light where it is needed. At LHC the light on the floor doubled from 150 to 300 lux, while the power per fitting dropped from 400W to 150W.

Which high bay suits a mounting height of 8 m?

For 8 m and around 300 lux in a production hall, 150W high bays with a 90° beam are a common choice. The high bay used here can be set to 90W, 120W or 150W, so the same fitting fits different heights and light levels. The exact layout follows from a DIALux light study.

Are LED high bays suitable for dusty steel processing?

Yes. The high bays used here are IP65 rated, so they are dust-tight. That keeps metal dust out of the housing and the driver, which matters in steel and metal processing.

How was the saving of €8,960 per year calculated?

The old installation drew 16,000W, the new one 6,000W. At 2,800 operating hours a year that is 28,000 kWh less. Multiplied by €0.32/kWh, that gives €8,960 a year. Losses of the old ballasts are not included, so the real saving is higher.

Can you make a free light plan for my production hall?

Yes. Send us a floor plan or a few photos with the ceiling height. We make a free DIALux light study, work out how many luminaires you need and send a non-binding quote at direct-import prices.