Energy Efficiency in the European Union

Refrigerators and freezers were among the first appliances to be labeled under the European Union labeling scheme in 1995. These refrigerators on display at Domotechnica 1997 are all in classes B and C. The most efficient class in the labeling program is A and the least efficient is G.

Figure 1. The EU energy label provides information on the absolute performance and physical characteristics of the appliance, including the annual consumption of energy (in kWh per year) and the storage volume of the compartments (in liters).

This refrigerator from the Korean manufacturer Daewoo was one of many innovative new energy-efficient technologies displayed at Domotechnica 1997. The door is made of an opaque glass that turns transparent with the flick of an orange switch. People can spend endless minutes peering into the refrigerator without opening the door and wasting energy.

Figure 2. This shows the change in the sales-weighted energy performance index used in the EU to define the energy efficiency of cold appliances. The index is a ratio of the energy consumption of a given cold appliance and the average energy consumption of an identically featured cold appliance available for sale in 1991. A lower index value indicates a more efficient product.

This clothes washer from German manufacturer Foron has a water storage tank in the front of the unit so water from the rinse cycle can be stored and reused.

Figure 3. Efficiency of 1997 models of cold appliances available on the European market for three major manufacturers.

This clothes dryer uses a heat pump to heat air at the condenser and then circulate it within the drum, where it humidifies. The air is then dehumidified by passing over an evaporator, which enables the vapor to condense. Unfortunately, this appliance is offered at twice the price of the standard technology, but the 40%-50% energy savings achieved take it into class A of the energy label.

More and more European-made freezers have a high level of insulation--as thick as 10 centimeters (4 inches). This makes the model more energy efficient and earns it an A or B grade on the energy labels.

The 1997 fair showed that appliance manufacturers have made visible and quantifiable efforts to introduce more energy-efficient appliances onto the market (see "Some Highlights of the Domotechnica 1997 show"). This positive development is a result of policy initiatives by the European Commission, and in particular of the EU-wide mandatory energy performance labeling scheme for appliances.

Cool Transformation

P>The display of this new label isn't yet mandatory for product promotions at professional exhibitions and trade fairs. At Domotechnica 1997, manufacturers were divided between those who made use of the energy label and those who did not. In some cases, manufacturers only displayed the label on their more efficient models (classes A, B or C).

Two recent analyses of the French and European markets quantify the progress in energy efficiency achieved so far. These show that the energy efficiency of European refrigerators and freezers has improved significantly since 1993, when HFC 134A and hydrocarbons were chosen as CFC substitutes. The studies forecast that this improvement in cold appliance energy efficiency would save 2,780³ kWh of electricity and reduce consumer bills to the value of 39 billion ECU (U.S.$43.7 billion) by the year 2020, even without the introduction of minimum energy efficiency standards. However, a new European Directive passed on September 3, 1996, will impose mandatory minimum energy efficiency standards for refrigerators and freezers in 1999, and this will certainly encourage European manufacturers to improve the performance of their least efficient appliances (see Figure 2).

At Domotechnica, several manufacturers revealed new lines of refrigerators and freezers that were dominated by high-efficiency models. The German manufacturer AEG (Allgemeine Elektrizitaetsgesellschaft--or "General Electricity Company") has stated that in the future at least 80% of its appliances will be in the efficiency classes A or B. This came about as a result of an agreement between AEG and the World Wildlife Fund called Consensus 25, through which AEG has pledged to improve the energy efficiency of its products by an average of 25% between 1995 and 1999.

The improved energy efficiency of European-made refrigerators and freezers is opening a gap between European models and non-European models. General Electric (GE), a major U.S. manufacturer, is offering a wide range of U.S.-made refrigerators for sale in Europe. When tested according to the European standard, the models in General Electric's catalog are on average 42% less energy efficient than those offered by European manufacturers Electrolux and Bosch-Siemens (see Figure 3). The best energy label ranking in GE's EnergySmart™ line of US-made refrigerators was a C. Most of their more efficient models are manufactured in Europe.

The improvements observed in European cold appliances have been achieved principally through advances in the quality of insulation. More manufacturers are using low-conductivity evacuated panel technology, although it is usually confined to their top-of-the-line models. This technology makes it possible to achieve optimum efficiency with thin walls, freeing up storage space.

Unfortunately, one of the most important manufacturers of evacuated panels, Owens Corning, has announced the suspension of its product line. However, several alternatives are available. A German appliance manufacturer is producing its own evacuated panels; Imperial Chemical Industries (ICI) is producing lightweight and comparatively cheap panels that are made of evacuated expanded polyurethane and which have conductivity values several times lower than traditional polyurethane foams; and a Turkish refrigerator manufacturer has encased evacuated insulation panels, not in polyurethane foam, but in preformed blocks of expanded polystyrene (EPS) encapsulated in plastic panels of the same material. This assembly facilitates recycling of the material at the end of the appliance's life.

Numerous manufacturers have achieved higher refrigerator and freezer efficiencies by redesigning their cabinets to use thicker conventional foam insulation. Other technical solutions include the use of high-efficiency compressors, improved heat exchangers, and electronic control systems to improve the regulation of compartment temperatures.

Many refrigerator and freezer manufacturers claim that the efficiencies of their best compressors have improved by 40% compared with conventional models. This is achieved mostly through the use of variable- or rated-speed drive systems linked to electronic controls. These compressors are available with a wide range of cooling capacities and are both hydrocarbon and HFC 134A refrigerants.

The trend toward efficient (class A or B) refrigerator-freezers with only one exterior door has received less publicity. Traditional refrigerator-freezers have two independent doors (one each for the refrigerator and the freezer compartments), but these two-door appliances rarely rank better than class B. The apparent shift in the market toward more single-door refrigerator-freezers with small freezer compartments may be an indirect consequence of the energy label requirement. This trend will probably be at the expense of single-door refrigerators rather than two-door refrigerator-freezers, since the freezer compartment in the single-door models appears to be too small to make them competitive with the two-door refrigerator-freezers.

Washer Wisdom

The second factor is the European Commission's decision to impose mandatory minimum energy efficiency standards for clothes washers. The European industry doesn't want new mandatory standards. It has entered into discussions with the European Commission to reach a voluntary agreement to improve the energy efficiency of European clothes washers.

The technical solutions to reducing the energy consumed by clothes washers while improving washing performance mainly involve optimizing the programming and control of the wash cycles. These are "soft" options, as opposed to "hard" options, which might require a major restructuring of the physical design of the machine. This explains how the industry in general has managed to introduce rapid, low-cost improvements in energy performance.

The cycle programming for some top-of-the-line machines is now held in a reprogrammable chip that can be updated by the manufacturer's technicians in the purchaser's home to incorporate improved cycles account for future developments in detergents. In theory, this option will extend the life of the appliance. At the very least, it should allow the purchaser to profit from future advances in clothes-washing technology.

Almost all of today's European manufacturers have some machines that can complete a full wash cycle using less than 60 liters (15.8 U.S. gallons) of water. The energy label and the voluntary agreements reached with the European industry have already led manufacturers to remove energy-inefficient models from the market. Future energy economies will come by encouraging consumers to use cooler water washes and higher spin speeds, and to run fewer small loads.

Understanding that the control panel can help guide consumers toward the most efficient use of machines has led AEG to install interactive commands in some of its new models. For example, when the spin speed is selected, the amount of residual moisture left in the clothes at the end of the cycle is displayed automatically. The user quickly learns that higher spin speeds reduce drying time. Another panel automatically indicates the washing time associated with the water temperature of any wash. AEG hopes that in this way it can interest the user in the operational costs of the machine. However, it will only be possible to verify the savings from these kinds of measures by conducting some discrete end-use measurement campaigns.

Dryers Still Hogging the Kilowatts

AEG displayed a prototype using an electric heat pump, the Öko-Lavatherm WP, which is a big improvement in energy efficiency but extremely expensive. The machine heats air at the condenser and circulates it within the drum. The air picks up moisture in the drum and passes over an evaporator which enables the vapor to condense. Unfortunately, this costs twice as much as the standard models, which use an electric-resistance heater to dry the laundry. The 40%-50% energy savings achieved with this machine take it into class A. The refrigerant currently used in the heat pump is HFC 134A: AEG would prefer to use a hydrocarbon refrigerant, but it is concerned that the quantity of fluid needed--about 250 grams--might pose a risk of fire or explosion in the event of a leak. Hydrocarbons are commonly used in domestic refrigerators, but only those appliances require 50 to 80 grams.

Thanks to this prototype, AEG has a good chance of winning the contest organized by a consortium of energy agencies under the umbrella of the International Energy Agency. A press conference was held during Domotechnica to announce the terms of the competition. Manufacturers are challenged to put onto the market class A clothes dryers that use neither CFCs nor HFCs and sell for less than 1,000 ECU (about U.S.$1,120).

Heat pump or gas-fired clothes dryers and hot-fill clothes washers (compared to the typical cold-fill washers with internal-resistance heaters) represent promising alternative demand-side technologies. They may be particularly useful in helping to avoid the need to upgrade power transmission lines in rural areas.

Sleep with the Dishes

Overall, Domotechnica 1997 was encouraging from the perspective of appliance energy efficiency. The challenge now is to bring all those innovations into the European market. Appliance manufacturers have shown some dynamism in proposing new technological solutions. Will retailers follow the trend? To what extent will homeowners see an energy-efficient product in the store, buy it, and use it properly? After manufacturers bring the products to market, policy makers, energy efficiency institutions, utility companies, and consumer associations need to maintain and pursue further efforts toward a more energy- efficient economy.
 
 

Some Highlights from the Domotechnica 1997 Show Refrigerators One Franco-Italian manufacturer exhibited a prototype series of upright freezers that use condensers (the heat exchanger at the back of the appliance) with phase change materials. This innovation has improved energy efficiency so much that all the models using this system are in class A. A German manufacturer has introduced a new series of convertible frost-free refrigeration appliances that use new developments in electronic control systems. Available in three different sizes, these appliances demonstrate the possibility of raising performance through the use of electronic controls, so that when the appliance operates as a simple refrigerator it is in class A. These appliances operate as class B upright freezers (interior temperature -18 °C), but can also operate as standard frost-free larder refrigerators (interior temperature +5 °C), as so-called frost-free refrigerators (interior temperature 0 °C), or as wine storage units (interior temperature +10-14 °C). According to the manufacturer, this flexibility does entail a higher cost; it is simply achieved by the intelligent use of the control system. In order to limit the ice buildup on freezer evaporators caused by humid air penetrating the storage space, Electrolux has invented an air bag system comprised of a pocket of plasticized aluminum connected to the freezer compartment via a narrow pipe. The bag expands and contracts in response to fluctuations in air pressure induced by the thermal cycling associated with the activation of the compressor cycle. This minimizes changes in air pressure inside the freezer space and thus reduces the amount of exterior humid air being drawn into the freezer, so that only 20% of the normal amount of ice is formed on the evaporator plate. Even more exotic is an innovation proposed by the Korean manufacturer Daewoo. Each compartment door in Daewoo's prototype refrigerator-freezer is made of electrochromic glass that can be changed from an opaque state to a transparent state simply by flicking a switch. This innovation should reduce the number of door openings required, since it enables users to inspect the contents of the refrigerator without opening the door. A study in France has confirmed that as refrigeration appliances become more efficient through the use of higher levels of insulation, their energy performance becomes progressively more sensitive to the number of door openings. Without doubt the most interesting refrigeration appliance at the fair was the combined refrigerator-freezer/gas-fired boiler and water heater exhibited by the German companies Rhenag and Thyssengas, the multinational Electrolux, and the Dutch agency for energy and the environment, NOVEM. This appliance is an upright cabinet split into four parts. The base contains the gas-fired boiler, above which is the refrigerator compartment. Then comes the freezer compartment, and at the top is a storage tank containing 80 liters of hot water. All the functions of the appliance are powered by gas, including the refrigerator-freezer, which operates using the gas absorption refrigeration principle. In winter, the gas boiler heats the household and simultaneously provides domestic hot water (DHW) in the same way as a standard gas-fired boiler system. However, the refrigerator-freezer receives all the energy it needs as free heat from the boiler and deposits its own waste heat in the hot-water storage tank. In summer, a small supplementary boiler provides the energy required for the absorption cycle and the DHW supply. The advantage of this design is that it makes use of the waste heat normally lost from conventional boilers to provide the energy needed for domestic refrigeration. The refrigeration cycle itself operates more efficiently than a standard absorption system because the heat transfer at the condenser is raised by preheating the DHW in a heat exchanger. Overall, the energy required for the refrigerator-freezer can be considered free in comparison to a conventional system. This concept is not totally new, but the Domotechnica show marked the first time an operational prototype has been exhibited. Assuming that this technological curiosity can function perfectly in practice, it has many possible applications.  Clothes Washers Several manufacturers displayed machines with A/A/B performances (A's for energy efficiency and washing quality, B for spin drying quality), but the German manufacturer Miele was one of the few to exhibit a triple-A machine. Miele achieves A-grade spin drying performance by using a 1,600 rpm spin speed (one of the two highest on display). This spin speed leaves only 44% of the residual moisture in the clothes after spinning. Another German manufacturer, Foron, displayed two clothes washers that have a water reservoir to recycle the water from the last rinse. Total water consumption for a complete wash cycle is reduced to 43 liters (11.3 U.S. gallons). Both Foron and AEG now produce clothes-washers with two water in-flows, one for hot water and one for cold, allowing the use of water heated externally to the machine through nonelectric means. This innovation can help economize on primary energy. Although it has been a common feature of machines aimed at the UK market for many years, it has seldom been available in machines sold on other European markets. Another technical innovation was exhibited by the Korean manufacturer Samsung, who has replaced the conventional clothes washer ballast with an ingenious system of steel ball bearings that move freely in an enclosed ring fixed to the outside of the drum. During the spin drying phase, the bearings move to counterbalance any clumping of the clothes, which would otherwise shift the center of mass away from the axis of the drum. The overall effect is to reduce vibration and make higher spin speeds possible. The disadvantage is that the use of the balls raises the effective thermal mass of the drum; thus more energy is needed to maintain the temperature of the wash water. Clothes Dryers Miele has developed another interesting product, a gas-fired evacuation clothes dryer. This type of appliance is already available on the North American market and to some extent in the UK. The use of gas in place of electricity has several advantages, including faster drying times, energy savings (particularly in terms of primary energy) and reduced operating costs. The cost of the gas is typically one-half to one-third the cost of electricity. The appearance of a gas-powered clothes dryer in a major European manufacturer's catalog will probably stimulate the market for this type of appliance. The price is about 350 ECU (U.S.$392) higher than the price of a conventional model.

Paul Waide is the director of PW Consulting, an energy efficiency consulting firm based in the U.K. and France. Benoît Lebot is an administrator for the Energy Efficiency Policy Analysis Division at the International Energy Agency in Paris.

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