Dimmer switches are primarily useful for two reasons: controlling mood and reducing energy consumption. By dimming your main light source, secondary light sources can flourish. Areas of light and dark create visual interest and mood, whereas an over-lit space looks two-dimensional and dull.
There are essentially two types of dimmer switch:
- Leading edge dimmer switches are mainly used for incandescent and halogen lighting, although many retrofit LED lamps allow backward compatibility. These switches use simple technology and are accordingly relatively cheap.
- Trailing edge dimmers can also be used with incandescent or halogen lamps, usually with a ‘soft start’ feature that reduces premature failure in filament bulbs. This type of dimmer is well suited to the capacitive load of LED bulbs.
LED bulbs or luminaires always require a dimmable driver before they can be dimmed by any switch. However, they are generally very good for dimming once compatibility has been established.
Dimmer switches have various physical design features, including:
- Flat plate: extremely low-profile, usable only on perfectly flat walls or tiles.
- Low profile: a slim but raised profile that allows installation on uneven surfaces.
- Moulded: an inexpensive plastic switch for use in areas where appearance is of lesser importance (e.g. workplaces, utility rooms, larders).
- Screwless: provides a neat finish with no visible fixings, and installs easily by clipping onto a rear mount.
The term ‘gang’ refers simply to the number of switches on a wall plate.
The term ‘way’ refers to the ability of a switch to operate in union with other switches. For example, 2-way switches can be installed in pairs to control the same light from two locations.