merchandising purposes by the food retail industry, such as grocery stores, supermarkets, convenience stores and specialty food stores. Commercial refrigeration equipments are also used by foodservice industry, such as restaurants and cafeterias. Commercial refrigeration equipment includes self-contained and remote condensing commercial refrigerators, commercial freezers, commercial refrigerator-freezers and commercial ice-cream freezers as well as self-contained commercial refrigerators with transparent doors designed to pull-down temperature. In the 19th century, the Americans used ice-cubes to refrigerate foods due to lack of ice-storehouses and iceboxes. As these two became widely available, Americans started using axes and saw to harvest ice for their storehouses.
Commercial refrigerators such as freezers and refrigerator-freezers are used to chill perishable products on display at grocery stores or convenience stores, restaurants or other food retail and food service establishments. Due to constant cooling requirements of these products, commercial refrigeration equipment is generally operated for 24 hours per day. Larger sized commercial refrigerator used in grocery stores consumes up to 17,000 kilowatt of power per year, while a large commercial freezer can use up to 38,000 kilowatt of power per year. Dairy products constantly need refrigeration. Meats, poultry and fish also required to be kept in climate-contro