Background to the Project

Heals department store in Tottenham Court Road, London is full of history and heritage. Dating back from the 19th century it has been a historic store renowned for its high end products and quality for over a century. At the back on the store there is a fabulous spiral staircase which winds its way up from the basement all the way to the top of the building.

As part of a refurbishment programme Heals asked our sister company  Classical Chandeliers to hang a large Bocci design chandelier with 80 globes in the stairwell.  At this time they were consulting with us over lighting for the stairway and we suggested using LED strip to light up the treads, which was looked on very favourably.  In order to make the effect spectacular but not obtrusive we designed a special profile wooden section which allowed the strip to be housed with the electrical feed wire but kept everything well hidden. The effect can be seen in this image with the warm white glow being cast across the treads.

This photograph from above shows the overall design impact of the strip and how is casts a subtle but effective light winding its way up the staircase.

A close up view can be seen below which shows the localised view that a person would see as they begin to climb the stairs.

When you look from above you just see this nice even glow but if you were to view from below you would see the actual LEDs on the strip  hidden inside the wooden section.

The Installation and Lighting Control Challenges

The effect was quite dramatic with the 80 globe chandeliers and the LED strip circling round the stairway over multiple floors. However the installation did present its own challenges. The strip was 65meters long so clearly we could not lust wire to one end as the voltage drop would be huge and this would mean that the light would be bright at one end but dull at the other. The solution was two fold.  Firstly we used 24 volt strip and 24 volt drivers so that current and consequently the  voltage drop is halved. Secondly we wired in sections using one large driver for each flight of stairs but powering both ends of the strip. A combination of these factors meant that we were able to achieve an even glow over the whole height of the stairway.

The other contribution factor from an installation perspective was that there was a vertical  access maintenance void the whole height of the stairway. This was useful for the wiring but did require a 1m masonry drill to get access through from the stairway.

There were a variety of method to control the strip. The most sophisticated was to use a dimming system. This could be achieved by dimming the first flight of stairs and then using data repeaters for each driver on subsequent flights. A RGB data repeated can be used but by linking the channels you can use twice the current. Whilst this option was presented then the route which was taken was to use a time switch to control the strip to come on every morning and go off when the store closed.