It is actually quite easy to predict illumination levels for Silescent Lighting LED Lighting Fixtures. 1 foot candle is equal to 1 lumen per square foot by definition. Since the actual fixture lumens are tested and certified, the exact number of lumens lighting an area such as a room can be easily calculated. To estimate foot candle levels for distances of from 5-8 foot from the ceiling mounted fixture in an enclosed room with 4 or more properly located fixtures, simply multiply the number of fixtures by their rated output, and divide by the room area in square feet. This will give you the estimated illumination level in foot candles for that space. This simple system works for this application because this particular light delivers basically planar source light rather than point source or linear source light, and reflection from walls, ceiling, and floor utilizes a high proportion of the light emitted from the fixtures. The illumination level is not as sensitive to distance from the light source in this range of ceiling heights. (This technique must be modified for higher ceiling applications, and does not apply to outdoor lighting applications). You will not exceed this value in the actual installation, but you will come within about 5 percent in most instances. Just adjust the number of lighting fixtures or the lumen output of the light fixtures to reach the desired lighting level.The majority of the foot candles being delivered to the room are direct from the fixture, and some are reflected off room surfaces. Reflective and light colored room surfaces improve room illumination significantly with this type of light as with any other system. For rooms with dark or non- reflective surfaces, increase the number of fixtures by 10-15 percent for best results.We have verified the above results for our LED Lighting Fixtures on numerous 8-10 foot ceiling installations. Remember, with Silescent Lighting LED Lighting Fixtures, you will need far fewer foot candles of illumination in order to achieve the same level of visibility. This is because Silescent Lighting LED fixture delivers a color spectrum that is evenly distributed, and the light is not delivered in 3 main monochromatic spikes as is done with fluorescents. This allows the human eye to see much better at lower levels of illumination. We have repeatedly seen that 45 foot candles of Silescent LED lighting appears brighter to nearly all room occupants than 90-100 foot candles of fluorescent lighting in the same room. If the lighting designer does not take this into consideration when specifying Silescent LED fixtures, the room will be overlit. Fortunately, all Silescent fixtures are fully dimmable and the light can be dimmed to a more acceptable level if necessary after the installation is complete.
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