Questions about Fluoro Lighting What is DeLamping? What about Mercury? Compare alternatives Whats the right light level?

WHAT IS DELAMPING     THE PROBLEM. Artificial light, powered by electricity, is used day and night around the world to illuminate spaces we occupy. In many parts of many buildings, though, the amount of light provided is much more than needed for the people in the room to do what they need to do. And in many cases the light fittings are also inefficient in delivering light to where its needed, which means the number of lamps used is more than necessary. A great deal of energy can be saved by reducing the number of lamps in a building, so spaces are adequately illuminated, but not overly illuminated. Delamping is cost effective. Payback periods are typically in the range of 1 to 2 years. In buildings such as office buildings, hospitals, schools, department stores, fluorescent lighting is a large proportion of overall energy use and carbon emissions. Delamping results in significant energy and greenhouse pollution savings. Reducing the number of lamps is called delamping. Delamping gives you the opportunity to easily and permanently: reduce energy use lower power bills cut greenhouse gas emissions reduce lamp replacement costs reduce circuit load throug reducing electricity demand It’s possible the building you are in now could halve its lighting energy by delamping. Will people complain? Most of us don’t look up and stare at the lights. People probably won’t notice the change. Are they hard to install? The reflectors are fitted by clipping them on, it couldn’t be easier. How long will they last? Sturdy construction means they will last for the life of the fitting. How will we know lighting is adequate with Reflectors? Use a lux meter to measure the lighting levels. If there are any problem areas, upgrade to one of our brighter fluorescent "quad-phosphor" tubes. We have tri-phosphor tubes in our light fittings. Don’t they save power? Replacing your old "halo-phosphor" tubes doesn’t really help. Though they produce more light, they use the same amount of energy. If you have tri-phosphor tubes s install reflectors and delamp half those tri-phosphor tubes. This will cut your power bills and slash your greenhouse gas pollution!     THE SOLUTION A reflector within the light fitting is a way to make an inefficient luminaire efficient. But the reflector must be carefully designed to provide optimum performance. The white painted surface that is there for the physical construction of the luminare is not sufficient.    WHAT WILL IT DO? The increase in efficiency that can be achieved by fitting a purpose designed silver specular reflector to an existing light fitting, and incorporating triphosphor lamps, is such that in most cases even though the number of lamps is reduced by 50% the illumination within the space is increased.   THINGS TO WATCH FOR There are different kinds of reflective materials, and types of reflection. Not all are economic even though initially they may seem cheap. Specular reflectance is mirror-like reflectance where the light ray is not scattered but is reflected perfectly. Specular reflectors are best for precise control of light. Diffuse reflectance is where the light reflected from a surface comes off at all angles with essentially no control on the direction of light leaving the surface. This what would happen with a matt white surface. Total reflectance is the combination of specular and diffuse reflectance; this is what occurs with real surfaces, with varying proportions of each.   THE IMPORTANCE OF THE REFLECTIVE SURFACE For optimum control and efficiency the best reflector is specular. The best material is polished silver as it is highly specular, it reflects evenly across the entire visible spectrum, and does not vary in reflective performance through life. To make reflectors from solid silver is economically impractical. In practice a specular silver film is aggressively bonded to an aluminium substrate. The surface must be protected by a scratch resistant coating (this also prevents the surface from oxidation), for additional protection during handling and installation the surface must be covered with a protective liner that is removed once the reflector has been installed. Make sure the reflector will maintain its specular reflectance throughout life.   A small decrease in specular reflectance has a great effect on overall efficiency. With just two reflections the intensity of light from a 95% efficient specular reflector will drop to 90% of the original. This compares to only 72% of the original intensity for an 85% efficient specular reflector.

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