A professional who installs, services, and repairs environmental control systems in residences, department stores, office buildings, and commercial establishments, utilizing knowledge of refrigeration theory, pipefitting, and structural layout. Responsibilities include:

• Mounts compressor and condenser units on platform or floor, using handtools, following blueprints or engineering specifications.
• Fabricates, assembles, and installs ductwork and chassis parts, using portable metalworking tools and welding equipment.
• Installs evaporator unit in chassis or in air duct system, using handtools.
• Cuts and bends tubing to correct length and shape, using cutting and bending equipment and tools.
• Cuts and threads pipe, using machine-threading or hand-threading equipment.
• Joins tubing or pipe to various refrigerating units by means of sleeves, couplings, or unions, and solders joints, using torch, forming complete circuit for refrigerant.
• Installs expansion and discharge valves in circuit.
• Connects motors, compressors, temperature controls, humidity controls, and circulating-ventilation fans to control panels and connects control panels to power source.
• Installs air and water filters in completed installation.
• Injects small amount of refrigerant into compressor to test systems, and adds freon gas to build up prescribed operating pressure.
• Observes pressure and vacuum gauges and adjusts controls to ensure efficient operation.
• Tests joints and connections for gas leaks, using gauges or soap-and-water solution.
• Wraps pipes in insulation batting and secures them in place with cement or wire bands.
• Replaces defective breaker controls, thermostats, switches, fuses, and electrical wiring to repair installed units, using electrician's handtools and test equipment.
• May install, repair, and service air-conditioners, ranging from fifteen to twenty tons cooling capacity, in warehouses and factory buildings and be designated industrial air-conditioning mechanic.