SANYO Develops Inverter driven Commercial Freezer with CO2 Refrigerant

Tokyo, December 2, 2009 – SANYO Electric Co., Ltd. (SANYO) is pleased to announce the development of a world first*1 inverter driven commercial freezer with CO2 refrigerant, and it will aim at practical use in the future.


 The CO2 refrigerant received a lot of attention at the 21st Meeting of the Parties to the Montreal Protocol (MOP21) held from November 4, 2009 to the 8th, because CO2 has a much lower global warming potential*3 of about 1/1430 to 1/3920, compared to alternative fluorocarbons*22 widely used for commercial freezers,. Therefore it can contribute greatly to the prevention of global warming. The newly developed technology was funded as a “Project to Support Introduction and Practical Adoption of Emission Control Equipment to Control Three Fluorinated Gas Substitutes,” by NEDO, Japan’s New Energy and Industrial Technology Development Organization. Through the development of a highly efficient split refrigeration cycle and a compact Two Stage Rotary CO2 Compressor, SANYO was able to realize energy-saving and CO2 refrigerant technologies for commercial freezers.
 Using the newly developed Inverter driven Commercial Freezer with CO2 Refrigerant, a customer can reduce CO2 emissions resulting from electrical consumption by up to 15%*4, compared to a conventional commercial freezer with alternative fluorocarbon (HFC) refrigerant(R404A). This can make a significant contribution towards the prevention of global warming and the realization of a low-carbon society.
 SANYO is promoting the development and application of CO2 refrigerant equipment for the prevention of global warming and the realization of a low-carbon society.

*1As of December 2, 2009, for commercial freezers
*2Compounds such as hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) used in industry as substitutes for banned chlorofluorocarbons (CFCs)
*3global warming potential: For the effect that the material of the unit weight discharged in the atmosphere gives global warming, CO2 as 1.0, it is the value that the effect was shown as a relative value.
*4Based on SANYO’s own testing data, compared to an existing SANYO model of single speed commercial freezer using R404A refrigerant.
I. Development Background  Adopted in 1987, the Montreal Protocol is an international treaty that requires member countries to reduce in stages the production and use of certain fluorocarbons such as chlorofluorocarbons (CFCs), once widely used in refrigeration and air conditioning equipment. Fluorocarbons destroy the ozone layer thereby affecting living organisms, and also have the potential to cause global warming. Today, alternative fluorocarbons, which do not damage the ozone layer, are used as refrigerants in refrigeration and air conditioning equipment. However, these alternative fluorocarbons still have a global warming potential that is 1,430 to 3,920 times greater than CO2. Given the concern that alternative fluorocarbons are continuing to accelerate global warming, emissions of these substances have been regulated under the Kyoto Protocol as greenhouse gases. Natural refrigerants, however, have a much smaller environmental impact than alternative fluorocarbons, and CO2 refrigerant in particular does not have the issues of toxicity and flammability found in some other natural refrigerants (see reference below).
 In 2000, SANYO developed a Two Stage Rotary CO2 Compressor, which was the first of its kind in Japan, and the following year the company used this technology to launch a CO2 heat pump water heater for household use (Ecocute). In 2007, SANYO came out with Japan’s first open front beverage showcase using CO2 refrigerant. Accordingly, SANYO has been leading the industry in CO2 refrigerant products. Commercial freezers are indispensable equipment for storing food products in restaurants, supermarkets, and convenience stores. Standards for commercial freezers are being investigated under the Top Runner Program*5 and Japan’s Act on the Rational Use of Energy, and there is a growing need for refrigeration equipment that can reduce CO2 emissions in order to prevent global warming.

*5Japan’s Top Runner Program seeks to improve the environmental performance of various types of products such as electrical goods and automobiles, by setting future industry standards based on the most advanced products currently on the market.

II. Forecast of effect of CO2 reduction 1. SANYO’s proprietary compact Two Stage Rotary CO2 Compressor  Compared to HFC refrigerant, CO2 refrigerant requires about four to ten times the refrigeration cycle pressure. This means there is a large difference in pressure between the high and low pressure stages of the cycle, requiring parts to be much stronger to endure the pressure conditions, in addition to greater motor torque. Using a two-stage pressure design for the compressor, the need for part strength and motor torque is roughly halved compared to single-stage compression. As a result, SANYO has succeeded in developing a CO2 cooling unit to be used for commercial freezers

2. SANYO’s proprietary high-efficiency split refrigeration cycle  When operating under high ambient temperatures (e.g. summer temperatures above 30°C), conventional CO2 refrigerant circuits become supercritical*6 and the coefficient of performance (COP) *7 drops to less than that for HFC refrigerant circuit. Therefore, SANYO developed a patented split cycle that utilizes the advantages of the company’s proprietary Two Stage Rotary CO2 Compressor, thereby realizing a major improvement in COP, exceeding the performance possible with HFC refrigerant circuit.
 Using a split CO2 refrigeration cycle, SANYO has improved efficiency by 20% to 30% compared to a non-split cycle. When the evaporation temperature is –30°C or lower, the new technology offers better COP than HFC refrigerant circuit (R404A), even under high outside temperature conditions.

*6Transcritical cycle: The temperature of a critical point of the CO2 refrigerative is 31.1℃, and it is low. It is a transcritical cycle at the refrigeration cycle that used the CO2 refrigerative exceeding a critical point. In supercritical, there is not defined difference between the gas and the liquid. There is no process of condensation at the refrigeration cycle.
*7COP(Coefficient Of Performance): This is a coefficient used as a standard of the energy consumption efficiency such as the air conditioner machines, and it is a value in which the cooling /heating ability per kilowatt of power consumption.

 III. Estimated CO2 reduction effect when using SANYO’s Commercial Freezer with CO2 Refrigerant Inverter  Compared to a commercial freezer using HFC refrigerant (R404A), the Commercial Freezer with CO2 Refrigerant Inverter reduces a customer’s CO2 emissions resulting from electrical consumption by up to 15%. Approximately 170,000 commercial refrigerator/freezers are shipped every year. By replacing the refrigeration unit with SANYO’s new technology, a customer can reduce CO2 emissions from electrical consumption*8 by about 14,000 tons per year. In the case of industry-wide conversion to CO2 refrigerant, we can eliminate the use of about 48 tons*9 of HFC refrigerant (equivalent to about 190,000 tons of CO2). By establishing high-efficiency technology within the commercial refrigeration temperature range, SANYO can develop a wide range of CO2 refrigerant applications for refrigerator/freezers, thereby greatly contributes to the direct reduction of the influence to global warming by the HFC refrigerant leakage that has been feared recently.

*8Calculated using an average annual electrical consumption of 4,451 kWh per commercial freezer, with a basic unit of consumption of 0.39 kg-CO2 /kWh
*9Calculated based on one unit containing an average of 0.28 kg of HFC