There has always been some confusion about how much
light you get from the different types of light bulb and how much energy they consume. The new breed of compact fluorescent (or ‘low energy’) lamps will only use around 11 watts of power to generate the same light as a normal 60 watt light bulb and they last up to eight times longer. There is no doubt at all that they save you money over the life of the lamp. A halogen bulb uses about half the energy of a conventional light bulb to generate the same amount of light.

Lightbulb Types.

These have been around for many years and are better known as the long white tubes commonly seen in utility ceilings. Recent technology has reduced the size and improved the efficiency. Many different shapes and power options are available. The benefits are low power consumption (around 20% of a conventional light bulb) and long life (up to 8000 hours). They are ideal for lights which need to be kept on for a long time. Many people assume fluorescent light is ‘cold’ but ‘warm white’ lamps are available which improve the colour.

These are the conventional bulbs which we all recognise and their chief advantage is the colour of light they emit. Colours of objects are generally more accurate with this type of light bulb and they impart a warm feeling to a room. The disadvantage is that they are inefficient by modern standards and have a relatively short life (around 1000 hours). Incandescent lamps come in a variety of shapes and sizes and have a number of different fittings: Bayonet cap (BC), Small Bayonet cap (SBC), Edison screw (ES or E27) and Small Edison Screw (SES or E14). The Edison screw types are becoming more popular in the UK. Several different coatings are also available with the following properties: Pearl is an all over frosting which diffuses the light and is best used in a light fitting with shades. Clear bulbs are more attractive when used in fittings where the bulb is visible or a sparkle is required such as crystal chandeliers

Halogen bulbs produce a very attractive light which closely resembles sunlight. They are more efficient than incandescent bulbs using only half the energy to produce the same light output and last twice as long.
Generally they are small lamps which generate a lot of heat so they can only be used in light fittings designed to cope with the higher temperatures. There are two main types of halogen lamp available in the domestic market:
Low voltage. These lamps operate on 12V which means a transformer has to be fitted either in the light fitting itself or remotely. The advantages of the lower power are that the safer voltage enables manufacturers to produce interesting and slim designs without the need to protect against danger from higher voltages. Transformers can be either electronic or ‘wire wound’. The newer electronic transformers are more energy efficient and smaller but more expensive than the conventional wire wound type. Electronic transformers can be damaged by voltage ‘spikes’ in the mains supply (sometimes referred to as ‘dirty mains’). These spikes can be caused by fluorescent lights, older motors, fridges, lift shaft motors etc. If persistent problems occur the use of mains voltage lighting is recommended.
Mains voltage. This relatively new breed of lamps offers the light colour advantage of halogen without the need to house a transformer. The reflector type bulbs are known as GU10 or GZ10 and the latest small envelope non-reflector halogens are known as G9.

Most tungsten and halogen light fixtures are dimmable but only certain types of fluorescent can be dimmed. When installing a dimmer you should check on the compatibility of the fitting with the dimming device and that the dimmer has sufficient capacity to control the load on the circuit.