Project: Mecona – LED high bays in a window and door production hall

Window, door and veranda manufacturer Mecona in Opglabbeek (Belgium) replaced 70 mercury vapour lamps of 400W in its production and storage halls with 70 LED high bays of 150W. The light level on the floor doubled from 150 to 300 lux, while the power for lighting dropped by 63%.

Project facts

Client	Mecona, manufacturer of windows, doors and verandas
Location	Opglabbeek, Belgium
Buildings	Production hall approx. 4,000 m² and hall approx. 1,000 m²
Completed	2023
Old lighting	70 × mercury vapour 400W
New lighting	70 × LED high bay 150W, 4000K
Mounting	6 m, suspended on chains
Control	Dimmable
Illuminance	150 → 300 lux
Planning	DIALux light study

The starting point

Mecona makes aluminium, PVC and wooden windows and doors and builds verandas. Profiles are cut, machined and assembled in a production hall of around 4,000 m², next to a hall of around 1,000 m² for storage and loading. Both halls were lit by 70 mercury vapour lamps of 400W each.

Too little light for precision work

With only 150 lux on the floor, the light was too weak for cutting, drilling and assembling profiles to the millimetre. Skylights help during the day, but on dark winter days and in the early morning the halls depend fully on artificial light.

High consumption

The 70 lamps drew 28,000W together, or close to 62,000 kWh per year at around 2,200 operating hours. Mercury vapour lamps also need several minutes to reach full light after switching on, and their output keeps dropping as they age.

The solution

Light study first

Before ordering, we made a DIALux light study based on the floor plans and the 6 m mounting height. It showed that 70 LED high bays of 150W, on the existing suspension points, would bring both halls to around 300 lux. So every mercury vapour lamp could be swapped one for one, without extra wiring.

70 LED high bays 150W

The new LED high bays hang on chains at 6 m. The luminaire can be set to 90W, 120W or 150W; here it runs at 150W. At 210 lm/W each fitting produces around 31,500 lumen, and the 90° beam brings the light down onto the workbenches and machines. Neutral white 4000K helps to judge colours of profiles, coatings and wood correctly. The high bays are 0-10V dimmable and IP65, so dust from cutting and sawing stays out. More on choosing wattage and beam per mounting height in our LED high bay guide and the beam angle guide, or see all high bays 150W.

LED luminaire used in this project

Energy savings in figures

Every mercury vapour lamp was replaced by one LED high bay. The table compares the old installation with the new one.

	Old	LED	Difference
Luminaires	70 × 400W mercury vapour	70 × 150W LED high bay	−250W per fitting
Connected load	28,000W	10,500W	−63%
Load per m²	5.6W/m²	2.1W/m²	−3.5W/m²
Illuminance	150 lux	300 lux	+100%
Consumption per year	61,600 kWh	23,100 kWh	−38,500 kWh
Electricity cost per year	€19,712	€7,392	−€12,320
CO2 per year	9.2 t	3.5 t	−5.8 t

How we calculated this

• Old: 70 × 400W = 28,000W × 2,200 h = 61,600 kWh per year.
• LED: 70 × 150W = 10,500W × 2,200 h = 23,100 kWh per year.
• Cost: 38,500 kWh × €0.32/kWh = €12,320 per year.
• CO2: 38,500 kWh × 0.15 kg/kWh = 5.8 t per year.

Ballast losses of the mercury vapour lamps are not counted, so the real difference is even larger. And the saving comes with twice the light on the floor.

Investment and payback

At current webshop prices, the 70 LED high bays cost €5,618. Half of the investment was covered by a relighting subsidy, leaving €2,809. With €12,320 lower electricity costs per year, that amount is earned back in under three months. Installation is not included in that figure.

Calculate the savings for your hall

The calculator below is pre-filled with the figures of this project. Change the values to see what LED high bays would save in your own production hall or warehouse.

The result

• Twice the light: 300 lux instead of 150 lux on the floor, enough for precise cutting and assembly work.
• 63% less power: 10,500W instead of 28,000W for the same 70 light points.
• Instant full light: no more warm-up time on dark mornings and no flickering.
• True colours: neutral white 4000K for judging profiles, coatings and wood.
• Lower running costs: €12,320 less on electricity every year and 5.8 tonnes less CO2.

Frequently asked questions

Which LED high bay replaces a 400W mercury vapour lamp?

A 150W LED high bay at 210 lm/W gives clearly more usable light than a 400W mercury vapour lamp. At Mecona, 70 fittings swapped one for one doubled the light level from 150 to 300 lux with 250W less per fitting.

Which wattage suits a mounting height of 6 m?

For 6 m and around 300 lux, 120W to 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 output can be matched on site to the height and the required light level.

How much light does a window and door workshop need?

For cutting, machining and assembling profiles, 300 lux on the work plane is a good minimum, with more locally at precision workstations. Neutral white 4000K and good uniformity help to see small details and colour differences.

Can LED high bays use the daylight from skylights?

Yes. The high bays are 0-10V dimmable, so they can be combined with a daylight sensor that dims the lights when the skylights let in enough daylight. That saves even more than the figures on this page.

Is there a subsidy for replacing mercury vapour lamps?

That depends on the country and region. On this project half of the luminaire investment was covered by a relighting subsidy. We tell you which schemes apply to your hall and supply the technical data needed for the application.

Can you make a free light plan for my hall?

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