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THE NEW WAVE OF
ENERGY EFFICIENT REFRIGERATORS

Swelling Energy Use

Refrigerators didn't get to be energy hogs on purpose. It's just that energy conservation ranked far below appearance and convenience on the list of design considerations in the '50s and '60s.

Energy guru Amory Lovins has often used the homely fridge as an example of how this approach affected energy use in the industrialized world. The motor was hidden underneath the appliance, where it radiated its heat right up into the food compartment. Manufacturers cut back on insulation so that they could increase the amount of usable space without making the appliance bigger -- not in itself a bad goal, but without high-performance insulators, this strategy allowed heat to stream right back into the cold box.

With little insulation, the refrigerator's metal skin got so cool that it tended to "sweat" -- to condense moisture from the air. So designers installed heaters on the outside of the fridge to evaporate the dew. The result was that a typical refrigerator in 1976 used an average of 1800 kilowatt-hours per year -- way more than any other appliance in the home. This was nearly four times the consumption of 1950-vintage models, which used about 500 kilowatt-hours a year and had their motors on top. By 1981, US models consumed twice the energy of Japanese models, according to Natural Resources Defense Council scientist David Goldstein.

The potential for conservation was not lost on energy-efficiency activists like Goldstein and Arthur Rosenfeld, formerly of Lawrence Berkeley Laboratory and now a senior adviser at the Department of Energy. The obstacle, as they saw it, was that the free market wasn't going to encourage the efficiency gains that technology allowed and society needed.

How It works

Electric refrigerators work on the same principle as perspiration: when a liquid evaporates, it draws heat away from its surroundings. Inside every electric refrigerator are tubes full of refrigerant, a fluid that boils at a low temperature. The refrigerant (formerly Freon, but in new appliances a compound of hydrogen, fluorine and carbon -- an HFC -- which has no effect on the ozone layer) is allowed to evaporate in a coil inside the fridge. This cools the coil; in most refrigerators, a fan blows air across the coil, into the freezer and fresh food compartment. In a manual-defrost model, the coils are built right into the sides of the freezer. Meanwhile, the cold, vaporized refrigerant is piped to the compressor, which increases the pressure on it and pumps it to the condensor coils, typically located behind the refrigerator. There the hot, compressed gas cools off, releasing heat to the surroundings, and turns back into a liquid. The liquid refrigerant passes through a pressure-reducing valve into the evaporator, where the cycle begins again.

Barriers to Conservation

One reason for this is that many refrigerators are bought by people who will never pay the utility bills to keep them running -- landlords and homebuilders. For homeowners replacing their own fridge, energy use is usually not a top consideration -- size, color and convenience tend to predominate. And even if they do take energy use into account -- using the yellow "Energy Guide" labels required on all major appliances -- they often demand that any extra investment pay itself back within a year or less, far less than the threshold of what would bring about all the cost-effective energy savings.

The choice of refrigerator is especially important because it determines the amount of energy the fridge will use, far more than how the consumer makes use of it. Regardless
of what your mother may have told you, opening the refrigerator door accounts for just 2% of the appliance's energy use. Another study showed that cleaning the coils in the back had no statistically noticeable effect on energy consumption. What mattered was the decision of what model to buy, not a decision to be more conscientious.

Energy Standards

So Rosenfeld, Goldstein and others pressed for standards that would set a maximum amount of energy use for each size of new refrigerator. The first such standard, set in California in 1976 over the protests of appliance manufacturers, required 18-cubic-foot fridges sold in the state to use no more than 1400 kilowatt-hours per year. Producers met the standard easily, and on time. Because California represented such a large share of the market, and the necessary improvements were so minimal, they applied that standard to their entire line. Since then, the criteria have been tightened three times. California set a new ceilings of 950 for 1987. Then federal standards took over, holding refrigerators to a maximum of 900 kwh in 1990 and 700 in 1993. The 1993 standards closed the gap between US and Japanese models, but the progress will continue: according to a pact concluded in April between the Department of Energy, appliance manufacturers and energy activists, the limit will drop to 500 kwh, effective 2001.

Design Improvements

The changes in refrigerator technology so far have been fairly mundane -- thicker insulation, more efficient motors, and anti-sweat switches, which allow the user to turn off the heaters in the outer walls of the fridge if it isn't "sweating". Improvements to the fan inside the food compartment have been doubly significant because inefficiency there costs twice: once in the motor's energy use, and once in having to remove the waste heat from the food compartment. Further gains in efficiency come from having a microchip control the defrost cycle instead of relying on a timer. (Defrost too often, and you needlessly heat the inside of the fridge; not often enough, and the ice on the cooling coils keep them from doing their job efficiently.)

The next round of energy cuts will take a bit more effort. Ideas include vacuum panels for insulation in the walls, and circulating the hot gas from the compressor along the outside walls to eliminate sweating.

Incentives for Manufacturers

Besides relying solely on the regulatory stick, energy experts dangled a carrot as well. In 1992, two dozen electric utilities banded together to offer a $30 million prize for the most efficient refrigerator design which beat the federal standards by 25% or more and used no ozone-depleting chemicals. Only companies which had manufactured at least 100,000 refrigerators annually for the previous four years were eligible to compete, shutting out upstart companies like Sunfrost (sidebar) which had been doing better than that for more than a decade.

The fridge: Pre-History

Long before the invention of chilling machines, people stored snow and natural ice from lakes to cool their food and drink -- since the days of the Greeks, Romans, and the early Chinese. Indeed, the first reference to the annual ice harvest comes from a Chinese poem dating to the twelfth century B.C.

In the United States, more than 14 million tons of ice per year were harvested at the peak of the ice trade around the turn of the century. Beyond merely supplying the northern cities, ice was shipped down the Atlantic coast and the Mississippi. Ice was even exported to the Caribbean. In rural areas without ready access to ice, people depended on cellars for cool storage or springhouses -- masonry or stone buildings built next to cold flowing water, which kept temperatures low.

When refrigerating machinery was invented in the mid-19th century, it made its first appearance in large factories where ice was manufactured in lieu of harvesting natural ice. American homes still had iceboxes -- tin- or zinc-lined wooden cabinets, typically insulated with sawdust, where a block of ice was used to keep the perishables cold. It wasn't until the 1930s that domestic refrigerators became widely available, thanks to the development of Freon, a refrigerant that was non-toxic and non-flammable. The first models had a place inside for a block of ice, so they could be used with or without electricity.

Whirlpool won the Super-Efficient Refrigerator competition with a 22-cubic-foot model that uses as little as 561 kilowatt-hours per year, depending on the options. To pocket the prize, Whirlpool had to sell 250,000 super-efficient fridges by July 1997; the money would be doled out as the special fridges were sold. But sales were low -- reportedly 30 to 35% below the quarter-million target -- and Whirlpool discontinued that model before the clock ran out on the program. Company spokesman Mike Thompson explains that consumers won't pay extra for a highly efficient product. Perhaps the stick beats the carrot
when it comes to appliance efficiency.

Whirlpool has been a long time leader in refrigerator efficiency, despite the disappointing showing of the Super-Efficient Refrigerator program. It held the record in the mid-'80s for most efficient US mass-produced fridge, with a model that used under 750 kilowatt-hours per year, about six years ahead of its time. In the mid-'90s, after a handshake agreement among the Deptartment of Energy, appliance manufacturers and energy activists for tighter
standards to take effect in 1998, Whirlpool launched a program to trim another couple of hundred kilowatt-hours annual consumption from models that already were under 700. Meanwhile, its competitors sought a delay from the Gingrich Congress and the Clinton White House, much to Whirlpool's displeasure. "We felt a deal was a deal," sniffs Whirlpool spokesman Thompson. This spring, the American Home Appliance Manufacturers trade group lobbied successfully to have the new standards put off from 1998 to 2001. Whirlpool quit the association in protest.

Effects on the ozone layer

Electricity use -- with its attendant air pollution, land disturbance and other impacts -- is just one of two principal effects refrigerators have on the environment. The other was the release of CFCs into the atmosphere, where they rose to great altitudes and damaged the Earth's protective ozone layer.

No one foresaw this hazard. When Freon and other CFCs were developed in the 1930s, they seemed like fabulous blessings of modern technology. Until CFCs, the available refrigerants -- usually ammonia and sulfur dioxide -- were all toxic, flammable, or both. Freon made domestic refrigerators widely accepted. Later, CFCs were used also to foam the insulation used in fridge walls.

It was only in the 1970s that scientists began to realize that the chlorine in Freon and other CFCs would break down in the upper atmosphere and create a reaction that destroys ozone molecules, thereby allowing damaging ultraviolet light to penetrate to the Earth's surface.

With growing recognition of the dangers, 86 nations agreed in 1992 to end the production of CFCs in the industrialized world by the end of 1995, and in the developing world by 2005. Refrigerator manufacturers scrambled for substitute refrigerants and foaming agents.

Two Solutions

The solution that has gained currency in the United States is to use HFCs -- ozone-safe hydrofluorocarbons -- as the refrigerant, and HCFCs -- hydrochlorofluorocarbons, which have reduced ozone-destroying power -- in the foam insulation. The solution is a victory for DuPont and other manufacturing giants, which produce these chemicals. HCFCs are just a temporary solution, because they are slated to be phased out, by 2020 in the North and 2040 in the South. According to the Worldwatch Institute, DuPont bet heavily on HFCs and HCFCs, investing more than half a billion dollars in their development.

Critics charge that these are imperfect solutions at best. For one thing, HFCs are potent greenhouse gases, with the potential to affect world climate even if they are ozone-friendly. They're also incompatible with some common materials and lubricants. Supporters of HFCs, such as NRDC's David Goldstein, point out that the amount of HFCs in each fridge is relatively small, so that the entire effect of a refrigerator's HFCs on the climate is only 1% as great as the influence of its energy consumption. If a non-greenhouse
substitute for HFCs increased a fridge's energy use by more than 1%, he says, it would be a net loss for the climate.

The Edge of the Envelope

The 2001 standards will nearly close the gap between mass-market refrigerators and hand-made fridges which were developed for the off-the-grid market. When native New Yorker Larry Schlussler, holding a freshly minted PhD in engineering, developed his ultra-efficient refrigerator in 1979, its consumption -- just 300 kilowatt-hours for a 16-cubic-foot model -- seemed like science fiction. Mass-produced fridges at the time used nearly four times as much power. The savings for remote users were immediate, because they could get by with fewer solar panels and batteries.

Sunfrost models are still made to order in a converted dairy in the northern California town of Arcata. Two- to four-inch-thick insulation, better door seals and latches, no fan, and a top-mounted compressor and condenser account for the extra-low energy use. Schlussler and his 14 employees turn out about 600 fridges a year, priced between $1200 and $2800 apiece, depending on their size. The low end of the price range applies to tiny models -- 1 or 4 cubic feet -- including a vaccine storage unit exported to the developing world. Regular kitchen-sized models are $2400 and up.

Other highly efficient fridges are available from in Michigan (4 to 8 cubic-foot models, marketed to Midwestern homesteaders and the Amish), and the Danish made Vestfrost, a 250-kilowatt-hour, 12-cubic-foot model, available through a California distributor.

The other solution -- being pushed heavily by Greenpeace under the Greenfreeze label -- is to switch to a greenhouse-neutral hydrocarbon (HC) like propane, isobutane, or a mixture of the two. These chemicals have the added advantage of being in the public domain and one-twentieth the price of HFCs. The drawback is that they are flammable. The issue isn't really safety, because of the small amount of butane in a fridge -- roughly twice what's found in a cigarette lighter. Much greater fire hazards can be found in most kitchens in the form of a gas stove. No, the problem is liability -- if the gas stove starts a fire in the kitchen, the fridge manufacturer doesn't wind up in court. In Germany, where product liability law is not so exacting, hydrocarbon refrigerants have taken over the market.

Refrigeration in the developing world

Greenpeace is promoting hydrocarbon refrigerants heavily in the developing world, where stakes are high. Annual refrigerator sales in less-industrial nations are growing at 15% per year. China has the biggest refrigerator industry in the world. Where virtually no Chinese homes had fridges 15
years ago, now 20 to 25% of them do -- as high as 90% in the cities. Other nations, Indonesia and India in particular, are seeing similar rates of growth.

The arguments for hydrocarbon refrigerants are especially powerful in these developing nations where CFCs are still allowed. Ultimately, local industries will have to convert away from CFCs anyway; if they convert to HCFCs, they will have to re-convert again in a few decades. What's more, if they use hydrocarbons, they won't depend on Northern chemical companies for HFC and HCFC technology, which is not as widely distributed as the refining technology needed to produce hydrocarbons. As a result, Worldwatch Institute reports that 8 of China's 12 largest fridge makers have converted to hydrocarbon technology for foam insulation, and several, with 30% of the market, have adopted hydrocarbons for both foam and refrigerant.

Sources for More Information

Written by: Seth Zuckerman,

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