Clean your plates
And lower your energy bill with a new high-efficiency dishwasher
Dear Jim: My 12-year-old dishwasher is noisy and does not have many cycle options. I think it’s time to replace it. What are the important efficiency features when I compare models? Is hand washing dishes more efficient? - Sandi T.
Dear Sandi: The good news is using an automatic dishwasher is typically more efficient than hand washing dishes (although if you take your time and are very miserly with water usage, hand washing can be more efficient).
But your old dishwasher probably does need to be replaced because it has already survived longer than most typical dishwashers. No matter which new dishwasher you select, you can be certain it will use less electricity and hot water than your old one.
The majority of the cost of using a dishwasher is for the energy to heat the water. A portion of this energy is used by the home’s primary water heater, the rest by an internal heater in the dishwasher. It’s simple, if a dishwasher design consumes less water, less energy is needed to wash dishes. So always compare the overall water consumption specifications for an average load cycle.
Of course, the most important feature is how well a washer cleans dishes. If it does not clean well, people tend to run it on the heavy cycle when normal will do, or they hand rinse the dishes first. Rinsing can use more than 10 extra gallons of water, and if hot water is used, more energy is being consumed. With a good dishwasher, a simple hand scraping of dirty dishes should be adequate.
Top-of-the-line dishwashers offer many cycle settings to fine-tune the process to the cleaning needs of the specific load. This is a nice feature, but most families can get by with three basic cycles: light, medium, and heavy (for pots and pans).
Some dishwashers also sport a two-pump design in the bottom of the tank. One small pump is used for spraying the dishes and another is used to drain the unit. Many models still use a single reversing pump which sprays in one rotation and drains in the other. Two smaller pumps require a smaller water reservoir, but the efficiency difference between one- and two-pump models has narrowed considerably.
Newer dishwashers are also much quieter than older ones, accomplished by better motor/pump design and higher levels of insulation — both for noise reduction and for better efficiency. Layers of insulation are placed around the pump assembly and the walls of the cabinet and door.
Automatic dirt sensors measure the turbidity (cloudiness) of the water to determine when the dishes are clean and how long to run the cycles. A filter option strains the water inside the dishwasher to remove food particles. Self-cleaning models use a grinder, but this may increase the noise level. A rinse-hold feature uses only two gallons of water to rinse the dishes if you do not plan to run the dishwasher for a long while.
The following companies offer efficient dishwashers: Asko, (800) 898-1879, www.askousa.com; Bosch Appliances, (800) 944-2904, www.boschappliances.com; Dacor, (800) 793-0093, www.dacor.com; Kitchenaid, (800) 422-1230, www.kitchenaid.com; and Miele Appliances, (800) 843-7231, www.mieleusa.com.
Have a question for Jim? Send inquiries to: James Dulley, Illinois Country Living, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.