Delfshaven, Rotterdam: classic lanterns converted to LED without replacement

A harbour district with a character of its own

Delfshaven is one of the oldest parts of Rotterdam: a historic harbour with warehouses, quays and narrow streets. The classic lanterns belong there as much as the bridges and the facades. In a protected townscape, replacing them with a modern luminaire is not an obvious choice, while conventional lamps use a lot of energy and have a short life.

The answer was a retrofit: the lanterns stayed on their columns and were fitted internally with an LED module and driver. From the outside nobody can tell the difference; the light has simply become more even, without glare. Lichtplein was not involved in this project; it serves here as an example of what a retrofit in a historic district involves.

What a retrofit kit actually does

In a retrofit, the installer replaces only the inside of the luminaire. Lampholder, control gear and discharge lamp come out; an LED module, a driver and usually a surge protection device go in on a mounting plate. Housing, canopy, glazing and column stay where they are. That means:

• No excavation, no new foundation or cable.
• A short job per column from the access platform, without a long road closure.
• The streetscape stays intact, which is decisive in a protected townscape.

What it delivers

A classic lantern with a conventional lamp easily draws 60 to 90 W including control gear. An LED module of 20 to 40 W at 130 to 150 lm/W gives the same amount of light or more: roughly half to two thirds less consumption, and less spill light into the sky and onto the facades.

A discharge lamp lasts 12,000 to 20,000 operating hours; a good LED module reaches 50,000 hours (L70) or more. At around 4,000 operating hours a year, that is well over ten years without a lamp change.

What to check before a retrofit

• Housing. Cracks, corrosion or a leaking canopy make a retrofit pointless: the IP rating is only as good as the weakest gasket.
• Light distribution. Choose a module with a distribution comparable to the old lamp, otherwise dark patches appear between the columns. In residential streets an average of 3 to 5 lux is usually sufficient.
• Colour temperature. Warm white (2200 to 3000 K) suits a historic district; 4000 K looks cooler.
• Surge protection. Choose a driver with at least 10 kV protection.
• CE and warranty. Ask for a CE declaration covering the complete kit and record who stands behind the assembly.
• Column connection box. Check the fuse and the earth braid; NEXUS supplies boxes to the Dutch standard for one or two fuses.

When replacement is the better choice

If the housing is worn out, a new classic luminaire on the existing column is often cheaper than a retrofit. The classic post-top luminaire from POLARIS has 40 W, 4,000 lumens, IP66 and fits an 80 mm spigot. If the column is due for replacement too, combine it with a conical steel column from TURRIS of 4 or 6 metres or an aluminium column from CIVIS. Lichtplein supplies these to installers and municipalities: luminaires and steel columns from stock, aluminium columns on a project basis, with up to 5 years' warranty on the luminaires.

Frequently asked questions