New dishwashers work smarter, cheaper — quietly

Q: My old dishwasher is very noisy and leaves spots and specks of food on the dishes. Are the new super-quiet, high-tech models much more energy efficient? What efficiency, convenience and noise reduction features are best? - R. S.

A: Not only is your old noisy dishwasher hard on your ears, but it is very hard on your wallet. For a typical family of four, a dishwasher is a significant electricity user. It uses some electricity to operate the motors and even more to heat the water and dry the dishes.

Even though your old dishwasher still works, installing a new one can be a wise financial investment. Whereas a typical old dishwasher uses about 12 gallons of hot water per load, the quietest new designs use as little as 4 gallons. Over its life, the savings can pay back its cost.

Also, for acceptable cleaning with your old one, you most likely have to keep your water heater thermostat set at 140 degrees. Many new models have built-in heating elements so that you can keep your water heater set at 120 degrees and still get clean dishes.

The noise level also has been reduced to a whisper in the best models. Look for a model with heavy wall insulation. This blocks sound and vibration and keeps the water hot for energy savings too.

The most efficient and quiet dishwashers use two small motors and pumps instead of one large reversing motor/pump assembly. One powerful high-pressure pump is used just for spraying during the wash portion of the cycle. The second quiet higher-volume, but low-power pump, is used just for draining.

With a two-pump system, each pump is smaller, so a smaller water reservoir is needed in the bottom of the dishwasher. This requires less hot water. Another advantage of using separate drain and wash pumps is better cleaning.

Whether you choose a super-efficient two-pump or a single-pump system, select a model with triple self-cleaning filtration. The wash water is highly filtered during each washing cycle. At the end of each wash cycle, the waste water automatically flushes out and cleans the filters.

An optional super-high temperature sanitizing setting is a good, healthful option. A built-in heating element heats the water to between 160 and 180 degrees for sanitizing. All these models have child-safe knobs to lock them shut.

A fairly new efficient and convenient feature on some models is an automatic cycle sensor (CleanSensor or Intellisense). These models sense the amount of soil on the dishes and adjust the cycle time and water temperature.

Super-quiet dishwashers are also most efficient

Several of the high-quality stainless steel European models use a condensing method of drying to eliminate excess heat and humidity in the summer. Cool room air is circulated in a heat exchanger to condense the sealed dryer air and the moisture drips into the bottom of the tank.

A new model (by Aquatec) just being introduced into the United States uses a very tough, never-rust, polypropylene foam tank. This muffles the noise and insulates the interior to keep the water hot for efficiency. There is also a quiet, portable mini-dishwasher (by Richlund) which can be placed on a kitchen counter after dinner. It's about the size of an 18-inch box.

Write for Utility Bills Update No. 703 — buyer's guide of the most efficient and quietest dishwashers, water usage, number of pumps, wash cycles, convenient features, prices and efficiency tips. Please include $2 (with check payable to Jim Dulley) and a business-size SASE. Mail to: Jim Dulley, Illinois Country Living, P.O. Box 3787, Springfield, IL 62708. For instant download, go to http:// www. dulley. com.

James Dulley is a mechanical engineer who writes on a wide variety of energy and utility topics. His column appears in a large number of daily newspapers.

Copyright 1998 James Dulley

18 ILLINOIS COUNTRY LIVING NOVEMBER 1998