Retrofitting hall luminaires to LED: lessons from Messe Basel

Key points at a glance

Many halls, sports facilities and industrial buildings have luminaires whose housings and reflectors are still in perfect condition, but whose lighting technology is outdated. Instead of replacing everything, such fittings can be converted to LED with a retrofit kit. Messe Basel chose this route for around 1400 hall luminaires; according to the contractor smarterion ag, the key figures are:

1400luminaires converted during ongoing operation

around 50%lower energy consumption

over 50'000 hservice life of the LED light sources

Figures provided by the contractor for the Messe Basel project

Retrofit or replace?

Full replacement looks simpler at first glance. In practice, the better solution depends on the existing installation. The following criteria help weigh the options.

Criterion	Favours retrofit	Favours replacement
Condition of housings and reflectors	Mechanically sound, easy to clean	Corroded, damaged, yellowed
Ceiling geometry and suspension	New luminaires fit poorly or require alterations	Standard dimensions, simple like-for-like swap
Appearance	Should be preserved, for example for architectural reasons	Design may change
Quantity	Large series of identical luminaires	Many different types
Sustainability goals	Materials and embodied energy should be conserved	Not a priority

Sustainable does not only mean using less electricity; it also means not having to throw things away.

What a retrofit involves

A professional conversion is more than a lamp change. Typically, each luminaire goes through these steps:

Removal of old lamps and ballasts.
Cleaning of the reflectors so that light output is right.
Installation of new LED modules and drivers, with a DALI interface if required.
Individual testing of each luminaire before refitting.
Reinstallation and commissioning, ideally section by section so operations can continue.

Controls are often the underestimated benefit. With DALI, individual luminaires or groups can be switched and dimmed as needed, for example for set-up, exhibitions and cleaning. This saves further energy and makes the hall more flexible to use.

Test field and planning

Before hundreds of luminaires are converted, a test under real conditions is worthwhile. At Messe Basel, a ceiling section with nine converted luminaires was run continuously over an extended period. This makes it possible to judge light effect, glare, colour rendering, heat and everyday suitability before going into series.

What lighting design should check

Illuminance on the working area, matched to how the hall is actually used.
Colour rendering and colour temperature, especially where products are displayed or events are filmed.
Glare from the typical viewing angles of visitors and staff.
Flicker-free dimming, including for camera and video recordings.
How the drivers cope with heat under the hall ceiling.

Safety and conformity

Anyone who substantially modifies a luminaire takes on responsibility for its electrical safety and conformity. Clarify with the supplier who bears this responsibility and which tests are documented. Also check the current rules on fluorescent lamps and possible funding programmes for efficiency measures, for example through ProKilowatt.

The business case should include energy costs, maintenance effort, lifting platform and staff costs, and the expected remaining life of the building. With high ceilings, eliminating lamp changes is a significant cost factor.

Working during ongoing operation

In large installations, logistics is often the real challenge, not the technology. At Messe Basel, the work was carried out on a rolling basis over several weeks while the hall remained in use. A dedicated cleaning installation was built for the large reflectors.

Plan work sections so that events and escape routes are not affected.
Keep enough spare luminaires so that no gaps appear.
Organise transport, interim storage and cleaning as a separate process.
Carry out acceptance and measurement records section by section, not only at the end.

Disposal must not be forgotten: old fluorescent tubes contain mercury and do not belong in construction waste. They must be collected separately and disposed of properly through the established take-back systems. Clarify in the quote who is responsible and how disposal is documented.

Frequently asked questions

Which buildings are suited to a retrofit?

Mainly halls, sports facilities, industrial and commercial buildings with many identical luminaires in good mechanical condition whose lighting technology is outdated.

Why not simply buy new luminaires?

Because a conversion saves material, preserves the appearance and is often simpler where ceiling geometry is difficult. Whether it is cheaper can only be shown by a case-by-case comparison.

What role does DALI control play?

DALI makes it possible to switch and dim individual luminaires or groups. This adds operational flexibility and further savings.

What does a service life of over 50'000 hours mean in practice?

Fewer interventions, fewer lifting platform deployments and fewer interruptions. In large installations, this significantly reduces maintenance costs and coordination effort.

Is a test field really necessary?

For large quantities, yes. It shows light effect and reliability under real conditions and reduces the risk of repeating a mistake a hundred times.

How long does such a project take?

That depends on quantity, access and how busy the hall is. Besides the conversion itself, which can take several weeks for large installations, allow time for the test field, evaluation, procurement of the kits and acceptance. A realistic schedule also takes the events calendar into account.

Messe Basel shows that an LED retrofit need not be a stopgap. Planning existing stock, operations and light quality together delivers modern lighting with less material.