Lighting quality and economics
In many projects, lighting is often the last thing to be considered when doing the costing. This often results in its being done on the cheap to keep the project within budget. As a consequence, the lighting installation may actually spoil the environment, decrease human efficiency, increase accident rate, and so on.
Money allocated to (or already spent on) other parts of the project is therefore wasted, because without good lighting to back it up, the project as a whole is unlikely to come up to the performance requirements expected of it. It is essential, therefore that the need for proper lighting be considered early in the project design phase and the appropriate budgetary arrangements be made to accommodate this investment.
But investment costs apart, the annual costs involved in running and maintaining the lighting installation are also very important and these too should he budgeted for in the design phase. And needless to say, one should not be persuaded to cut down on either of these costs at the expense of lighting quality. The pressure to do so is often particularly great when different departments are responsible for these two aspects of the lighting. The situation may be even more complicated in this respect as when, for example, maintenance and energy costs are also so divided among departments.
Investment cost breakdown. The investment costs for a particular lighting installation can he split up as follows:
• luminaire costs, including control gear (where applicable),
• lighting control systems (e.g. dimmers);
• mounting accessories;
• electrical wiring;
• installation costs
The most important running costs are those involving:
• lamp replacement;
What is lighting efficiency?
Three types of efficiency. One must distinguish between three types of efficiency when considering lighting systems:
• Lighting hardware efficiency
o This includes light source, control gear, optical system, luminaire housing, etc.
• Lighting installation efficiency
o This is largely dependent on the choice, location, and setting up (e.g. aiming) of the lighting hardware
• Usage efficiency
o This depends largely on the type of lighting control system employed.