Kitchen Products ReviewNew Features and Technologies Boost Refrigerator Efficiency

Manufacturers and energy conservation experts agree that of all kitchen appliances, the refrigerator uses the most energy because it is always on.

But strategies for making the product more energy efficient vary, as companies experiment to find the best solutions. From improved insulation to new compressor technologies, appliance makers continue to introduce new ways to make refrigerators more efficient. And with Energy Star requirements tightening, energy costs rising, and green living taking center stage, pros should expect homeowners to begin demanding those resource-saving features just as much as stainless steel finishes and built-in ice makers.

Outside Protection
Green building expert Michael McDonough says the solution is simple: Maximize insulation. "The refrigerator is like a jacket," says the New York City architect. "You want your jacket to be thick to keep the cold out, just like you want your refrigerator walls to be thick to keep the cold in.

"The zipper, cuff, collar, and string tie at the bottom of the jacket are the refrigerator gasket," he says. "You want to keep that as tightly closed as possible."

Manufacturers are vying to invent jackets with the tightest cuffs and collars by improving gasket technology. Trends in this sector include refrigerator doors that seal shut for a period of time and alarms that warn consumers when the door is left open.

The popularity of foam-in-place insulation, in which the walls, ceiling, and floor of refrigerators are filled with liquid expanding foam, also is growing. Tiny air pockets in the foam prevent heat transmission from the outside to the inside of the appliance. "It's like filling a balloon with water ... it coats everything, every crack and crevice," says Andy Sinclair, Whirlpool's Energy Star government relations specialist, who also notes that foam makes the fridge more rigid and sturdy, reducing the use of steel and cutting down on production energy costs.

Energy-Saving Technologies
Paralleling insulation-improvement feats are innovative manufacturing technologies in-volving compressors, defrosting systems, and specific low-energy consuming modes to reduce energy consumption.

Marc Perez, vice president of Liebherr North America, says more manufacturers are incorporating variable-speed compressors, whose functionality he compares to that of a car engine. "You use more energy when you turn your car on and off, and the same goes for your refrigerator compressor," he says. "Variable compressors conserve energy by barely ever going off; they keep running at what would be a very slow revolutions-per-minute rate."

Liebherr, SunFrost, and Sub-Zero offer dual refrigeration system technologies, which give both the refrigerator and the freezer their own compressor. Each compressor only runs enough to keep its specific compartment cool, cutting down on energy consumption and keeping the temperature more constant.

Progressive defrost systems also are emerging. Whirlpool and Sub-Zero employ an adaptive defrost-control system that electronically calculates the amount of time needed in between defrost cycles to conserve energy, instead of running on an automatic time cycle. Bosch models also have sensors that constantly measure interior temperature, to provide consistent cooling and aid in controlling the frequency of the defrost cycle.

SunFrost uses a partial auto defrost system. According to owner Larry Schlussler, there is no air passage between the refrigerator and the freezer, "so when you open the refrigerator door, the warm air that gets in doesn't form into ice around the freezer coils." Ice builds up very slowly, he says, "so we don't use the big 600-watt heater that comes on every day to melt [ice], like in conventional refrigerators." Instead, if consumers turn off the refrigerator for about 20 minutes the small amount of ice will melt.

In addition, some models offer mode settings that adjust energy output for lifestyle changes. Bosch models, for example, include a Sabbath mode, during which the unit uses less energy; an economy mode, which adjusts the temperature for extra efficiency when the fridge has minimal contents; and a vacation mode, which adjusts the temperature and disables water and lighting.

Bosch's Evolution models also offer exterior temperature controls that allow homeowners to make adjustments without opening the door and letting cold air out.

Rising Star
The driving force behind many of these energy-efficient efforts is competitive pressure. All refrigerators sold in the United States must meet the Department of Energy's efficiency standards, but many companies' units meet the more stringent Energy Star qualifications, as their major competitors are achieving the rating. As of April, to acquire an Energy Star logo, refrigerator models must use at least 20 percent less energy than the federal standard, a 5 percentage point increase versus previous requirements.

"Energy Star products continue to become more widely available across a variety of price points and are affordable to most groups," says John Brumleve, an engineer and systems manager for GE Refrigeration. "While there may be a slight price premium on Energy Star products, consumers will more than [make up] that investment in utility cost savings."

Still, while interest in energy efficiency may be increasing, some designers find that it is often not consumers' highest priority. For Suzanne M. Evensen, a certified kitchen and bath designer for Evensen Interiors in Topanga, Calif., "energy efficiency is only a priority for me if it is something my client is very conscious of," she says, "and while some of them have interest, it is not something that many clients prioritize." Evensen says about 10 percent of her clients are green and Energy Star-conscious.

"I can't say I see any trends in terms of requests for energy-efficient refrigerators in my experience," concurs Mark Kresge, a certified kitchen designer in Columbus, Ohio. Kresge thinks consumers "just assume that the refrigerators are eco-friendly because most have become more energy efficient."