Businesses and other organizations depend on complex electronic equipment for a variety of functions. These complex pieces of electronic equipment are installed, maintained, and repaired by electrical and electronics installers and repairers.
Most people are familiar with plumbers who come to their home to unclog a drain or install an appliance. In addition to these activities, however, pipelayers, plumbers, pipefitters, and steamfitters install, maintain, and repair many different types of pipe systems.
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.