空调和制冷系统的维修------外文翻译.doc

外文翻译(2) repair heating and air-conditioning systems Job prospects for heating, air-conditioning, and refrigeration mechanics and installers are expected to be good, particularly for those With technical school or formal apprenticeship training. The Air-Conditioning Excellence program, offered through North AmericanTechnician Excellence, is the standard for certification of experienced technicians. What Would those living in Chicago do Without heating, those in Miami do refrigeration? Heating and air-conditioning systems control the temperature, humidity, and the total air quality in residential, commercial, industrial, and other buildings. Refrigeration systems make it possible to store and transport food, medicine, and other perishable items. Heating, air-conditioning, and refrigeration mechanics and installers—also called technicians—install, maintain, and repair such systems. Because heating, ventilation, air-conditioning, and refrigeration systems often are referred to as HVACR Heating, air-conditioning, and refrigeration systems consist of many mechanical, electrical, and electronic components, such as motors, compressors, pumps, fans, ducts, pipes, thermostats, and sWitches. In central heating systems, for example, a furnace heats air that is distributed throughout the building via a system of metal or fiberglass ducts. Technicians must be able to maintain, diagnose, and correct problems throughout the entire system. To do this, they adjust system controls to recommended settings and test the performance of the entire system using special tools and test equipment. Technicians often specialize in either installation or maintenance and repair, although they are trained to do both. Some specialize in one type of equipment—for example, oil burners, solar panels, or commercial refrigerators. Technicians may Work for large or small contracting companies or directly for a manufacturer or Wholesaler. Those Working for smaller operations tend to do both instal