With electricity prices expected to rise again next year, a growing number of Americans are on the lookout for new ways to conserve energy. To this end, dimmers are a simple and convenient solution. By adjusting light levels, they provide greater control over home energy consumption. However, there is some confusion about whether dimming lights really lowers electricity costs. Some homeowners assume dimmers work like resistors, blocking the flow of current. Many are surprised to learn that lighting technology in modern dimmers is far more sophisticated and produces much greater savings.
How Do Dimmer Switches Work?
Dimmable lights date back to the 19th century, when electricians discovered how to restrict the flow of electricity into light circuits with devices called rheostats. Rheostats reduced output, but didn’t reduce power consumption. The circuit still drew the same amount of energy; rheostats just prevented some of it from reaching the light source. This was not only wasteful. The technology was also large, clunky, and hard to operate. Unused current was converted into heat, creating a potential fire hazard as well. Theaters used rheostats for lighting effects, but they were too dangerous for private homes.
That changed in 1959, when an electrical engineer named Joel Spira created a solid-state semiconductor device called a TRIAC, which was small enough to fit into a standard light switch. TRIACs dimmed lights without restricting the flow of electricity. Instead they “chopped” the leading and trailing edge of the incoming waveform. In other words, they shut the light on and off rapidly, up to 120 times a second, powering it with electric pulses rather than continuous current. We don’t notice because the flickering is too fast to be detected by the human eye, so all we see is a dim but steady light output.
Does Dimming Lights Save Electricity?
Today’s dimmers are far more energy efficient than Joel Spira’s prototype. When used consistently, they can cut lighting costs by as much as forty percent. However, not every type of bulb works well with a dimmer switch, which can affect your savings.
- Incandescent Bulbs. Traditional light bulbs with a filament contained inside a glass enclosure. Nearly all of them work well with light dimmers. Incandescent lights typically last around 1,000 hours when run at full brightness, but last two to three times as long when connected to a dimmer.
- Halogen Bulbs. Halogen lights are a type of incandescent bulb that use halogen gas to create a reversible chemical reaction cycle that captures and returns tungsten to the filament as it’s burned off. Lowering the light level interrupts this process, forcing the bulb to act more like an ordinary incandescent, shortening its lifespan.
- CFL Bulbs. Compact Fluorescent Lamps (CFL) generate light with a tube of argon and mercury vapor rather than a filament. CFLs are efficient, but not all of them are compatible with dimmers. Check the package before purchasing.
- LED Light Bulbs. Light Emitting Diodes (LED) produce light by running an electric current through a semiconductor. LEDs typically last 50,000 hours, but dimmable LED lighting can last up to 100,000. Unfortunately, while LEDs are a great choice for modern dimmers, they’re often incompatible with older models. Upgrading to LED bulbs lowers your electric bill, but may require you to upgrade your dimmers at the same time.
Save on Electrical Repairs with EnergyGuard™
Dimmer switches require strong internal wiring. Regrettably, heat, corrosion, and mechanical stress can gradually degrade the wiring in your home, leading to shorts and outages. Home insurance doesn’t cover damage from this type of wear and tear, but Agway’s EnergyGuard™ Program does.
When the need for repair occurs, our customers don’t waste time searching for a qualified repairman. They call us instead. Our service team maintains a network of local HVAC contractors and sends the first available one straight to your door. Unlike other home repair programs, there are no service fees or deductibles. We pay for the visit and all covered parts. Avoid unexpected costs. Sign up and start enjoying the benefits of EnergyGuard™ today!
