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Under Control |
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Iain
Carlile, Senior Designer, dpa lighting design, explains
how energy savings can be made and benefits gained for the end user,
through the use of intelligent lighting controls. Through the use of lighting controls the “Right Time” part of our philosophy can be successfully implemented. Lighting controls can be used to automatically lower a lights output through dimming and switching, without the need for user interaction. A light that is on, but not required (i.e. in an unoccupied space), no matter how efficient the light source, is wasting energy. A light that is on, which could be dimmed to a lower level to suit the task being performed, is wasting energy. A light that only comes on when it is required, at an appropriate dimming level, is not wasting energy. It is providing an appropriate illumination to undertake the task required. It is possible to achieve this through the use of a suitable lighting control system. Lighting controls are an important part of any lighting design, allowing the brightness of the illuminated elements within the visual field to be altered and balanced to suit the prevailing task, time of day, desired mood which is to be invoked, etc. When creating different lighting scenes through the dimming of light sources, an energy saving is made. The total running load of the installation will be far less than if all light sources were running at full output. In hospitality applications the actual running load over time can typically be 40% less than the total installed electrical load for lighting. In commercial applications, through the use a lighting control system with daylight and occupancy sensor inputs, it is possible to dim and switch off lighting when sufficient levels of daylight are present and also to switch off lighting which is not required because nobody is occupying the space. Again savings can be made on the running cost of the installation. There is much legislation and many energy assessment methods that attempt to control the amount of energy used by lighting installations. Most of these methods are based either on the efficacy of the luminaires installed or the electrical load per area of the lighting installation, rather than considering the total energy used by the application. Because of this, very few make any real allowance for the huge energy saving potential that can be achieved through the use of lighting controls. It is possible to have a very efficient lighting installation, which wastes energy due to a lack of lighting controls being present. For example, look at many commercial properties where all of the lighting is operational throughout the nighttime when the space is unoccupied. These installations can have efficient luminaires and lamps, achieving low installed electrical load per area and high luminaire efficacies, as required by most of the energy assessment methods, but by running all of the lighting for more than twice the required operational hours is a huge waste of energy. So paradoxically the installation may meet many of the different energy assessment methods and legislation requirements deeming the installation to be energy efficient, yet in actual fact the installation can be quite wasteful of energy since the lighting is not switched off when it is not required. The use of a suitable lighting control system would prevent this scenario from happening. In addition to lighting controls main benefits of scene setting and saving energy, it is possible in certain applications to utilise controls which also log data and feedback information aiding in the management and maintenance of the lighting installation. Correctly
designed lighting controls result in energy savings being achieved,
through the switching and dimming of light sources, without any compromise
of the resultant lit effect." |
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| "Right Light, Right Place, Right Time" |
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