NEW THINKING ON ILLUMINATION
Go up to the seventh floor of a nondescript 1950s building at Salford University and there, to the left of the reception desk, is a glowing orb implanted like a giant rainbow-coloured eggshell in the left-hand wall.
Watch it for a minute and you realise that the colours are changing like one of those mood-changer balls in the gadget catalogues that come with Sunday newspapers. It occupies a third or so of the floor space. It is multi-coloured and the colour changes have just speeded up and turned into a cascading fountain.
This is Salford's Think Lab, one of a number of (now unfortunately named) Da Vinci Labs set up by the university.
There is a Centre for Virtual Environments, an acoustic research lab and a materials research facility. But none has a glowing, colour-changing, blob-like wall like the one at the Think Lab. 'It's great, ' says Carla Kocsis, who runs the lab. 'It has a tremendous wow factor. It has made a massive contribution to the university.'
Apart from knocking the socks off visitors with its glowing wall, the Think Lab's purpose is to house eight visiting researchers and eight Salford post-graduates working in the fields of the built and virtual environment and informatics, covering humanenvironment interaction, virtual reality and 3D visualisation for the construction industry.
The pod encloses an oval space that looks disarmingly innocent, but has some very interesting features built in.
Outside and up close, the double curvature of the glowing wall turns out to be made from glass panels around 300mm square. When the lights are off they look milky; they are in fact laminated to give a frosted effect, which diffuses and refracts the light sources behind.
Architect Broadway Malyan/Manchester devised the pod idea and built it in collaboration with Antony Meadows of building services consultant S I Sealy, and Zumtobel lighting designer Greg Scott. The architect originally thought of using big panels of double-curvature glass, but the finished result was a more economical solution.
The glass diffuser panels are attached to rails, fixed to cranked steel sections, attached at regular intervals to floor and ceiling. The light sources are vertical trays, each with a very thin red, green and blue P5 fl uorescent tube, which have an intense output. Their support trays are then fastened to horizontal rails around 250mm behind the glass, the minimum distance at which the glass entirely diffused the source light, making the colour changes very smooth.
The lighting is managed by a Luxmate control system.
Luxmate commissioned it and its engineer chose one of the scenes - the technical name for lighting sequences. It is basically a heavy-duty version of the electronics used in domestic mood changers, in which each tray of luminaires can be addressed by the computer program running both this and the interior effects. The lighting designer works out what effect is required and the scene is programmed into a PC.
Although it is oval in plan, the room inside is more conventional, with vertical walls, a big screen blocking off one end and a flat, suspended ceiling. Panels in one wall give access to the rainbow skin's lamps and controllers. The end of the ellipse houses the light controls, two back projectors, computers, plus a control desk.
Zumtobel's Harry Barnitt says the pod is used in a variety of ways. One is to conduct round-table discussions with academics in far-off universities.
A table is set up and the distant team is projected on to the screen. Another use for the screen is as a lightboard, while the two projectors can be used for 3D imaging. The space is also used by researchers who need its facilities or just a place to sit and it is also rented out for seminars and functions.
The pod's ceilings are very interesting. In addition to the ventilation registers, there is a diffuser tile pattern of two squares with a bigger rectangle over the back. These are no ordinary diffusers, but Zumtobel lightfields.
For presentations, the need is for a combination of flat, even light with spot lighting to model the speaker's face or hands. Zumtobel creates ambient light using the lightfields, which look like ordinary 600mm square diffuser panels but are MPO units with three layers of diffusion. The top layer is a catch-all diffuser, which ensures that the light hits the next layer - an MPO, lasercut microprism optical diffuser - in an even way before being further diffused by the bottom diffuser. Barnitt says these are 82 per cent efficient, compared with 45 per cent efficient for normal diffusers, which waste quite a lot of energy. He adds: 'The problem with fluorescent lamp development is that the [lamp] envelope gets smaller and smaller and the light brighter and brighter, causing glare. So we have to put something between the lamp and people using a room - hence the complex diffusers. For the light field, which is probably unique to Zumtobel, the typical light source is two T5 lamps.'
The lights inside the pod can be programmed in the same way as the red-green-blue trays of the multi-colour blob skin. The three racetrack patterns of lightfields in the ceiling can be programmed in a series of scenes, from simply light chasing to dimming at the front for cinema presentations, lighting up the centre for round-table discussions and changing over the day. This is fairly standard stuff, but the researchers have started to use tracking cameras, which enable the lightfields to follow a lecturer around the room There is more to come, explains Meadows. Because the computers are deployed under the widely used DALI protocol, it is possible to connect environmental controls to the system - or anything else mechanical. For example, when the cinema movie goes to an Arctic scene the room could become cold, warming up in tropical scenes and perhaps blowing a breeze for scenes at sea. The possibilities are endless and these are the kind of effects that some of the lab's occupants are working on.
Meadows is plainly smitten and is going to stay involved.