A student trying to decide on a career in heating and cooling technology may have to base the choice on a variety of indirect evidence. Part-time or summer work is usually not available to high school students because of their lack of the necessary skills and knowledge. It may be possible, however, to arrange field trips to service shops, companies that develop and produce heating and cooling equipment, or other firms concerned with the environmental control field. Such visits can provide a firsthand overview of the day-to-day work. A visit with a local contractor or to a school that conducts a heating and cooling technology training program can also be very helpful. Explore industry associations' Web sites, such as Explore the Trades (https://explorethetrades.org), which provides detailed information on education and careers for heating and cooling technicians, electricians, and plumbers. The HVACR Workplace Development Foundation also offers a helpful Web site, http://careersinhvacr.org/site/1/Home.

Participate in trades-related competitions to test your skills against others and meet new people who share your interests. Competitions are sponsored by trade associations, schools, local park districts, companies, or membership organizations for teens. For example, SkillsUSA, a “national membership organization serving middle-school, high-school, and college/postsecondary students who are preparing for careers in trade, technical, and skilled service occupations,” offers a Heating, Ventilation, Air-Conditioning and Refrigeration Competition. Visit http://www.skillsusa.org to learn more. 

Many industries today depend on carefully controlled temperature and humidity conditions while manufacturing, transporting, or storing their products. Many common foods are readily available only because of extensive refrigeration. Less obviously, numerous chemicals, drugs, explosives, oil, and other products our society uses must be produced using refrigeration processes. For example, some room-sized computer systems need to be kept at a certain temperature and humidity; spacecraft must be able to withstand great heat while exposed to the rays of the sun and great cold when the moon or the earth blocks the sun, and at the same time maintain a steady internal environment; the air in tractor trailer cabs must be regulated so that truck drivers can spend long hours behind the wheel in maximum comfort and safety. Each of these applications represents a different segment of a large and very diverse industry.

Heating and cooling technicians may work in installation and maintenance (which includes service and repairs), sales, or manufacturing. The majority of technicians who work in installation and maintenance work for heating and cooling contractors; manufacturers of air-conditioning, refrigeration, and heating equipment; dealers and distributors; or utility companies.

Technicians who assemble and install air-conditioning, refrigeration, and heating systems and equipment work from blueprints. Experienced technicians read blueprints that show them how to assemble components and how the components should be installed into the structure. Because structure sizes and climate-control specifications vary, technicians have to pay close attention to blueprint details. While working from the blueprints, technicians use algebra and geometry to calculate the sizes and contours of duct work as they assemble it.

Heating and cooling technicians work with a variety of hardware, tools, and components. For example, in joining pipes and duct work for an air-conditioning system, technicians may use soldering, welding, or brazing equipment, as well as sleeves, couplings, and elbow joints. Technicians handle and assemble such components as motors, thermometers, burners, compressors, pumps, and fans. They must join these parts together when building climate-control units and then connect this equipment to the duct work, refrigerant lines, and power source.

As a final step in assembly and installation, technicians run tests on equipment to ensure that it functions properly. If the equipment is malfunctioning, technicians must investigate in order to diagnose the problem and determine a solution. At this time, they adjust thermostats, reseal piping, and replace parts as needed. They retest the equipment to determine whether the problem has been remedied, and they continue to modify and test it until everything checks out as functioning properly.

Some technicians may specialize in only one type of cooling, heating, or refrigeration equipment, such as window air-conditioning unit installers and servicers, who work on window units only. Air-conditioning and refrigeration technicians install and service central air-conditioning systems and a variety of refrigeration equipment. Air-conditioning installations may range from small wall units, either water- or air-cooled, to large central plant systems. Commercial refrigeration equipment may include display cases, walk-in coolers, and frozen-food units such as those in supermarkets, restaurants, and food processing plants.

Other technicians are furnace installers, also called heating-equipment installers. Following blueprints and other specifications, they install oil, gas, electric, solid fuel (such as coal), and multifuel heating systems. They move the new furnace into place and attach fuel supply lines, air ducts, pumps, and other components. Then they connect the electrical wiring and thermostatic controls and, finally, check the unit for proper operation.

Technicians who work in maintenance perform routine service to keep systems operating efficiently and respond to service calls for repairs. They perform tests and diagnose problems on equipment that has been installed in the past. They calibrate controls, add fluids, change parts, clean components, and test the system for proper operation. For example, in performing a routine service call on a furnace, technicians will adjust blowers and burners, replace filters, clean ducts, and check thermometers and other controls.

Technicians who maintain oil- and gas-burning equipment are called oil-burner mechanics and gas-burner mechanics, or gas-appliance servicers. They usually perform more extensive maintenance work during the warm weather, when the heating system can be shut down. During the summer, technicians replace oil and air filters; vacuum vents, ducts, and other parts that accumulate soot and ash; and adjust the burner so that it achieves maximum operating efficiency. Gas-burner mechanics may also repair other gas appliances such as cooking stoves, clothes dryers, water heaters, outdoor lights, and grills.

Other heating and cooling technicians who specialize in a limited range of equipment include evaporative cooler installers, hot-air furnace installer-and-repairers, solar-energy system installers and helpers, and air and hydronic balancing technicians, radiant heating installers, and geothermal heating and cooling technicians.

In their work on refrigerant lines and air ducts, heating and cooling technicians use a variety of hand and power tools, including hammers, wrenches, metal snips, electric drills, measurement gauges, pipe cutters and benders, and acetylene torches. To check electrical circuits, burners, and other components, technicians work with volt-ohm meters, manometers, and other testing devices.

Some technicians work in equipment sales. They are usually employed by manufacturers or dealers and distributors and are hired to explain the equipment and its operation to prospective customers. These technicians must have a thorough knowledge of their products. They may explain newly developed equipment, ideas, and principles, or assist dealers and distributors in the layout and installation of unfamiliar components. Some technicians employed as sales representatives contact prospective buyers and help them plan air-conditioning, refrigeration, and heating systems. They help the client select appropriate equipment and estimate costs.

Other technicians work for manufacturers in engineering or research laboratories, performing many of the same assembling and testing duties as technicians who work for contractors. However, they perform these operations at the manufacturing site rather than traveling to work sites as most contractors' technicians do. Technicians aid engineers in research, equipment design, and equipment testing. Technicians in a research laboratory may plan the requirements for the various stages of fabricating, installing, and servicing climate-control and refrigeration systems; recommend appropriate equipment to meet specified needs; and calculate heating and cooling capacities of proposed equipment units. They also may conduct operational tests on experimental models and efficiency tests on new units coming off the production lines. They might also investigate the cause of breakdowns reported by customers, and determine the reasons and solutions.

Engineering-oriented technicians employed by manufacturers may perform tests of new equipment, or assist engineers in fundamental research and development, technical report writing, and application engineering. Other engineering technicians serve as liaison representatives, coordinating the design and production engineering for the development and manufacture of new products.

Technicians may also be employed by utility companies to help ensure that their customers' equipment is using energy efficiently and effectively. Utility technicians, often called energy conservation technicians, may conduct energy evaluations of customers' systems, compile energy surveys, and provide customer information.

Technicians may also work for consulting firms, such as engineering firms or building contractors who hire technicians to estimate costs, determine air-conditioning and heating load requirements, and prepare specifications for climate-control projects.

The career of green heating and cooling technician is becoming increasingly popular due to the public's growing interest in energy efficiency and protecting the environment. Duties of these specialized technicians include installing and repairing energy-saving furnaces and air-conditioners (including those that are full- or partly powered by geothermal power, solar energy, or other sources of green energy) and conducting energy audits of homes and businesses to identify and eliminate areas where hot or cold air is being lost due to improper insulation and other factors.