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The Do's And Don't's Of Fitting Lights

The incorrect and correct way of fitting a light. The first light wastes energy by directing most of its light laterally or directly into the sky and needlessly causing light pollution.

(c) Institute of Lighting Engineers

The Do's And Don't's Of Fitting Lights
(c) Institute of Lighting Engineers

The Do's And Don't's Of Fitting Lights

The incorrect and correct way of fitting a light. The first light wastes energy by directing most of its light laterally or directly into the sky and needlessly causing light pollution.

(c) Institute of Lighting Engineers

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Light Designs And Light Pollution

The diagram shows the patterns created by three types of light. The first is not an efficient design because it casts light in a wide arc. The second is more efficient while a lot of energy is still wasted. The third maximizes the use of light. It is not necessary to use a 500W light when a more efficiently designed 150W light can suffice.

(c) Institute of Lighting Engineers

Light Designs And Light Pollution
(c) Institute of Lighting Engineers

Light Designs And Light Pollution

(c) Institute of Lighting Engineers

Enlarge image

For outdoor lights you should check that they are not causing any of the three problems mentioned previously – Sky Glow, Glare, or Light Trespass. Ask yourself these questions:

Is light from the fitting shining over the horizon?

Is the light from the lamp shining directly onto a neighbour’s house or onto the road?

Is the light lighting areas that you didn't intend it to – a neighbour’s garden perhaps?

Is the light the lowest wattage that it needs to be?

Is the light on only when it needs to be on?

The Institution of Lighting Engineers (ILE) recommends that external lights should not rate more than 150W. Many of the security lights on sale in Ireland are rated at 500W. So by replacing your lamp with a 150W fixture you could instantly cut your electricity bill for that light by over two thirds!

The lower wattages in 99% of cases provide sufficient illumination for a given task, thereby saving CO2 and costs.

Consider purchasing a light with a sensor that will only go on when it is approached. This will reduce the power used and also provide more security as you will be alerted by the light if there is any activity.

Fit the light correctly. By directing all the light where it is needed, you may see that you didn't really need that big expensive 500W floodlight after all! You can buy external lights that are designed to minimise light pollution, and existing lights can often be made better by adjusting their orientation.

The diagrams above show the do's and don'ts of fitting lights.

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