Q: I can't afford new energy-efficient appliances now, but with ever higher electric rates, I need to save. Do those inexpensive little "black box" electronic devices improve appliance efficiency?
A: You are referring to motor controllers for appliances. Plugging your appliances into inexpensive controllers can make them operate more efficiently than when they were new. A controller can reduce electricity use up to 15 percent, reduce repair calls and increase appliance life.
A controller instantaneously monitors the needs of the motor and gives it only enough power to match the load. You can use them on any appliances with motors -- refrigerators, freezers, washers and dryers, dehumidifiers, window air conditioners, sump pumps, tools, etc.
Controllers are particularly effective on old refrigerators because they reduce the heat created by the motor. Excess heat not only wastes electricity, but it also makes the compressor run longer to stay cold.
Older appliances often have motors that are more powerful than needed. These motors run 95 percent of the time at lower output than they were designed for, so they operate inefficiently and waste electricity.
A controller is a small radio-size device that you plug into any wall outlet. You plug the appliance into the outlet built into the controller. There is an indicator light to show you it is working.
I use a controller on my old refrigerator. Other than a lower-pitched and quieter sound of the motor, it operates as before. I move another controller from outlet to outlet when I am vacuuming or running the washer.
Most controllers have built-in high-voltage spike protection. There are many thousand-plus-voltage spikes in your house wiring. One large spike can easily burn out the controls in your appliances. Repeated smaller voltage spikes can slowly degrade the insulation and electronic components.
Soft-start is another built-in feature. This allows the current to ramp up slowly when the motor (refrigerator compressor) starts up. Soft-start reduces energy use and wear and tear on the motor and components.
Controller brownout sensors can save a motor from destruction. When voltage drops during a brownout or storm, a motor may stop running and just hum. In this state, it can quickly burn out if power to it is quickly limited.
Proper use habits are also important to keep your old appliance at peak efficiency. Keep them clean, especially refrigerators and clothes dryers.
Correspondence should be addressed to James Dulley, c/o Baltimore Sun, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.