Heating and Cooling Technicians

The modern heating industry got its start with the appearance of piped steam heating during the Industrial Revolution. Piped hot water heating replaced steam in the 1830s because of its improved comfort level and lower temperature requirement. Oil and coal heat in the late 19th and early 20th centuries have largely been superseded by today's natural gas and electric heating. Today, radiant heat and geothermal heating are becoming more important within the heating industry.

Cooling or air-conditioning mechanisms were virtually unknown until 1842, when Dr. John Gorrie invented a cold-air machine to relieve the suffering of yellow fever patients in a Florida hospital. Naturally occurring ice was relied on for refrigeration until shortly after the Civil War, when a process to produce artificial ice was invented and put to use in the southern states. The development of synthetic refrigerant gases in the early 20th century led to the widespread use of mechanical refrigeration by the 1930s and home air-conditioning by the 1950s. Today, approximately 88 percent of homes in the United States have some form of air-conditioning, according to the U.S. Department of Energy. The Lawrence Berkeley National Laboratory estimates that 700 million air-conditioners will be installed worldwide by 2030.

Initially, the equipment for the limited capacity air-conditioning, refrigeration, and heating systems was simple, and the skills needed to maintain them were comparatively easy to learn. Most technicians for this early equipment were trained by manufacturers and distributors. But as the field has expanded and the equipment has become much more sophisticated, workers have had to pursue more specialized knowledge and skills.