An Engineering Extension energy feature
An Engineering Extension energy feature
By Gene Meyer
Refrigeration is one of the top five energy uses in a home. The simplest way to reduce the cost of home refrigeration is to minimize the number of refrigerators and freezers in use.
It is not uncommon to have two refrigerators and a freezer in a home. One refrigerator is used in the kitchen. A second refrigerator may be located in the garage or basement to store beverages, produce, and other overflow items. This is a costly practice. Generally, a refrigerator consumes about1,500 to 2,000 kilowatt hours (kwh) per year. At eight cents per kwh, the annual operating cost is between $120 and $160. In addition, second refrigerators are often older, less efficient models, so actual costs may be higher.
A second way to reduce the energy costs of refrigerators and freezers is to keep the condenser coils clean. The condenser coils are located either at the rear or bottom of the unit. Before servicing, be sure to shut off the unit. On units with the condenser at the rear, use a vacuum cleaner with a brush adapter. Gently clean the coil and then turn on unit.
Condensers located on the bottom are more difficult to clean. After shutting off the unit, remove the bottom grill. Usually a spring clip on each side holds the grill in place. Once the grill is off, you can see the condenser. There are usually two or three sections of coil, each separated by a 1/2- to 3/4-inch gap.
To clean the coils, the dirt must either be brushed or vacuumed from the coil. Most vacuums come with a long, flat attachment for cleaning furniture cushions. You can use this to get between the coil sections. Unfortunately, most attachments are not long enough to reach the back of the coils.
Another way to clean bottom coils is to use a long, slender, round brush. Starting on the top coil, slide the brush along the right side of one coil. With a single motion, move the brush to the left and forward. Repeat, starting again on the right. Then move down a coil section. Use a vacuum to collect as much dirt as possible.
The frequency of coil cleaning will vary from household to household. Check the coils monthly until you have a feel for how often they need cleaned.
If the appliance is a manual defrost unit, defrost when the ice builds up to about 1/8 inch. Ice build-up reduces the efficiency of the unit.
Leaky door seals allow cool air to escape. To check for leaks, close the door on a piece of paper. The seals should hold the paper securely. If the paper slides easily, you may need to replace the seals. Also conduct a visual check of the door seals. Sometimes the seals crack or become deformed.
Some refrigerators and freezers have a humidity switch to control condensation on the outside of the unit. Turn off this switch during the winter.
Finally, check the temperatures in both the freezer and refrigerator compartments. Be sure that the thermostats are not set colder than required, 0 to 5 degrees for the freezer and 38 degrees for the refrigerator.
Proper maintenance will increase the life and performance of refrigerators and freezers while holding down energy costs.
Most new refrigerators are more energy efficient than those made even ten years ago. If shopping for a new refrigerator, check the energy guide which estimates the annual operating costs. Twenty cubic foot units are available with annual operating costs less than $50. But remember, don't just move that old one to the garage. You are better off buying one slightly larger and disposing of that old unit.