Thin bronze strips make light barriers

Tom Shelley reports on how a born again idea will greatly help users of solar screening, lighting and ventilation grilles

Micro louvred screens, with slats 1.27mm wide and 0.18mm thick, prove invaluable for reducing solar glare at low weight and cost, as well as simplifying ventilation grille and lighting design. Based on an idea invented by American John Grebe in 1939, they have now been brought to a manufacturing base in the UK and are in the process of being re-invented for new applications. Increased use in light fittings, ventilation grilles and other mechanically engineered produced are expected to result from an enhanced manufacturing flexibility made possible by the introduction of modern CNC control to the manufacturing process. The base idea of 'SmartLouvre' is to miniaturise the slats used in the venetian blind principle so that they have exactly the same effect as large louvres for reducing solar glare, while being much easier to support and handle. This allows them to be fixed to the outside of a window, so that sunlight does not get in through the glass while allowing occupants inside to see out almost without obstruction. They are made from a special bronze alloy, with an optional matte black paint finish, and can be cut to shape with shears, or fitted to a light fitting or ventilation aperture like wire mesh. Being closely woven, they keep out most insects, and stop direct rain penetration. Used in lighting, they are directional and as such, have been used on trading floors in India, in displays in museums, including the Imperial War Museum, and to shade traffic lights. They also work well as sun visors in cars, stopping glare while allowing the driver to see through them. They offer very little resistance to air flow, allowing them to survive 120 mph wind speeds, while acting as barriers to sound, reducing direct emissions by up to about 50%. Now that they and their production is in the hands of SmartLouvre Technology in Waterlooville, Managing Director Andrew Cooper has set himself the goal of re-engineering the machines, so that they can produce blinds of different louvre widths and spacing and in a range of materials and finishes. A sample in our possession is made of aluminium alloy instead of bronze. We have seen samples of black painted material laminated between glass sheets to provide glare reduction and/or improved privacy combined with mechanical reinforcement. And the two sides need not be painted the same colour. A guide price for product sold to end users is of the order of £60 to £80/m2, depending on product specification and quantity. Coopers email Coopers Pointers * Standard product consists of bronze louvres, 1.27mm wide, angled at 17 deg. Each louvre is 0.18mm thick and 1.5mm apart. * Standard product is gold coloured, or can be supplied matte black painted * It is intended to offer products with different dimensions, made from different materials and different colours front and back * The standard material, has low air resistance, can survive 120 mph winds and reduce direct sound emissions by up to 50%