Dimmer switches, also called rheostats, let you control the level of light emitted by light bulbs in light fixtures and lamps. They adjust illumination from brightness appropriate for reading and tasks such as cooking and sewing to the dimness of candlelight to create relaxing atmospheres or check on sleeping children without disturbance. Dimmer switches can be used on most fixtures and with various types of light bulbs.
Dimmer switches can be used on ceiling and pendant fixtures, table and floor lamps, ceiling fans with lights, sconces and recessed lighting. Recessed lighting systems typically use reflector bulbs to increase the reflective properties of the fixture, many of which are not dimmable, information that is available on the reflector bulb packaging.
Light Bulb Types
While most lamps and fixtures can be equipped with dimmer switches, not all dimmer switches work on all types of light bulbs. Most spiral or tube-style compact fluorescent light (CFL) bulbs with screw-in bases cannot be dimmed by rheostats designed to dim incandescent bulbs. This restriction is listed on the CFL package or lamp label. However, dimmer switches are available designed specifically for CFL bulbs. Standard dimmers work on all types of incandescent and halogen light bulbs but are not recommended for common fluorescent tube lighting as they shorten the life of the tube. All types of light bulbs used with dimmers should be labeled as dimmable or the rheostat will not work and the life of the bulbs will be shortened.
Benefits of Dimmer Switches
Dimmer switches save money through using only enough energy to provide the desired level of lighting, unlike three-way bulbs that offer limited options. Eyestrain is reduced by the availability of appropriate lighting for different tasks, and the mood of a room can be instantly transformed from bright and cheery to cozy and romantic.
Dimmer Switch Types
The most common type of dimmer switch is a round dial that is rotated forward and backward to control the degree of light. It is usually turned on and off by a push-button mechanism. Glider styles have a control lever that moves side to side or up and down. Programmable dimmer systems have presettable buttons that control several fixtures at once through a wall-mounted device or handheld remote control pad. Custom-designed dimmer systems control lighting levels throughout a building from a master control panel. Many dimmer controls glow in the dark for easy access.