Lighting
Effective lighting selection gives you the lighting you want, saves money and is easier on the environment. Attractive, energy-efficient lighting adds value to your home or business and reduces your energy bills.
However, only five percent of the energy that goes into a typical incandescent bulb comes out as light. The remaining 95 percent becomes heat. This can have a significant impact on energy consumption of air-conditioned buildings.
The lighting of a building should be considered early in the design stage, as it is here that major decisions can be made regarding the use of natural daylight.
Energy consumption of a lighting installation depends on:
- the efficiency of the various components of the system, e.g. lamps, ballasts, reflectors
- the way in which it is used, this is often strongly influenced by the control and the available daylight
- the maintenance regime.
Lamp Types
The choice of lamp type is an important consideration. Compared to traditional tungsten filament bulbs, Compact Fluorescent Lamps (CFL) use only about a quarter as much power as an incandescent lamp with the same light output. A 22 Watt CFL has about the same light output as a 100 Watt incandescent; an 18 Watt CFL is equivalent to a 75 Watt incandescent.
In an industrial/commercial situation, companies should consider using the new T5 rated fluorescent tubes in place of existing T8 or T12 types. These tubes cannot be used as direct replacement but when combined with high efficiency reflectors could increase the efficacy of luminaries by 30%. White SON (High Pressure Sodium) should only be considered for high bay areas. External or security lighting should be provided with Low Pressure Sodium (SOX).
Ballasts
There are a number of differences/benefits in using Electronic in comparison to Electromagnetic.
The main benefits with electronic are,
- Longer lamp life typically 40% is a conservative estimate. Therefore you can reasonably expect to have to replace the lamps twice with Electronic, where as you would have had to replace them three times in the same period with standard gear.
- Power consumption is lower for the same lamp.
- Rapid, reliable & flicker free operation of the lamps.
Reflectors
Developments in reflector technology and resulting availability of super reflective aluminium has seen improvements in light out of 10% over the standard reflectors available. The importance of a good maintenance regime to include regular cleaning of reflectors and lamps cannot be over emphasised if consistently high quality and cost effective lighting is to be maintained.
Reflectors also help to distribute light and control glare. Some designs work better than others. Direct light to surfaces and tasks, not to the floor. Choose reflectors that are easy to clean and allow easy replacement of lamps. It is extremely important to use lamps that the reflectors are designed for.
Control
Turning lights off when you're not using them is the most effective method of saving energy. But lighting controls such as automatic motion sensors, switch timers and conveniently located light switches will also reduce "on-time" of lights and produce savings. Dimmers cut energy use by reducing power to the lamp. They give you control over how much light you need, and when you need it.
Building
The lighting of a building should be considered early in the design stage, as it is here that major decisions can be made regarding the use of natural daylight.
A room's shape, size and colour affect how much light you need to provide. Spaces with dark surfaces and high ceilings are harder to light efficiently than spaces with low ceilings and light-coloured surfaces when the light source is at ceiling height.
