For this reason, it is universally accepted that in rooms requiring continual lighting it is preferable to use fluorescent tubes and compact lights which use the same technology rather than spotlights or incandescent lightbulbs. Although these lights are more expensive they work out cheaper in the long run.

 

In fact, it is proven that fluorescent lighting can last approximately ten times longer and consume four times less energy. The only thing we need to bear in mind is that these lights consume more energy at the time they are actually switched on than is required to keep them on for short periods of time.

 

The useful life of fluorescent lights is in the region of 5000 to 7500 hours. Although they can last an awful lot longer, after this period of time the light they produce is significantly reduced.

 

More light, less watts
However, in order to save energy it is fundamental to know how these devices and appliances work, the different types of energy they consume and the use we can get out of them.

 

A fluorescent tube is a source of light which is produced as a result of an electrical discharge inside an inert gas atmosphere containing low-pressure mercury vapour. This environment causes a light phenomenon known as fluorescence.

 

It is most often a glass tube the inside of which is coated in a fluorescent substance. Inside the tube there is a noble or inert gas (argon, krypton, neon�) rarefied with mercury particles. The ultraviolet radiation of the mercury vapour is turned into visible radiation.

 

Thus, a 32 watt compact fluorescent light, for example, produces the same amount of light as a 75 watt incandescent. There are numerous types of fluorescent lighting which permit electrical energy saving: rapid start and instant start which are generally circular or U-shaped. Their power ranges from 17 to 60 watts.

 

Tips for use and installation
The most common fluorescent lighting is a linear tube. They are usually straight but may also be U-shaped or round. The tubes can have a diameter of 7mm, 16mm, 26mm or 38mm. They are named according to a convention based on eighths of an inch: T2, T5, T8 and T12...

 

The smallest lights need to be supplied with power via electronic equipment. Where lighting efficiency is concerned (amount of light per watt of power), generally speaking the smaller the diameter, the greater the efficiency.

 

At temperatures below zero fluorescent light output drops. Nevertheless, various manufacturers produce lights with special covers or insulating tubes so as to light up the coldest places.
In order to reduce costs it is sensible to only light up the necessary areas using appropriate lights and tubes. Some tips are outlined below:
- Lights should always be switched off when they are not required. But in the case of fluorescent lights or tubes, if you are going to leave a room for less than 15 minutes it is advisable to leave them on because they consume more energy during the moment they are switched on than that consumed by keeping them on for a short period of time. Additionally, the switching on process also reduces the life of elements such as the ignition or the actual fluorescent light.
- Daylight is the best light and as such it is sensible to keep the curtains and blinds open during the day and to do as much as possible to make the most of it.
- In areas requiring less light we can use 25 watt spotlights, which are also often sufficient to provide light from multiple lamps.
- Some light fittings allow us to regulate the intensity of the light they produce, which are also known as �dimmer switches�, enabling us to adjust the light to the minimum required. We can also use timers and clocks which allow us to programme when lights come on or switch off at certain time intervals or at a specific time.
- It is recommended to install switches which only work when they detect the presence of people.
- The use of compact fluorescent lights also ensures reduced energy consumption. These lights are made up of a tube of between 10 and 16mm in diameter folded into an inverted U-shape. Due to their small size they can be used where linear lighting of a similar power does not fit.
- For working at a desk or office table it is best to use a fluorescent desk lamp.
- Both fluorescent and incandescent lights must be kept free of dust so that the dirt does not block out the light they emit.
For safety reasons it is essential to keep the electrical installation in optimum condition. Furthermore, a poorly maintained installation consumes more energy and may damage the equipment. Symptoms such as reduced light intensity when an appliance is plugged in or variations in the television picture mean that the electrical installation is not working properly or that something is in poor condition.