Operate, maintain, repair, or replace chillers, heat pumps, coolers, refrigeration units, variable air volume systems, air handling units, exhaust systems, condensers, evaporators, water heating units, and cooling towers; replace heating coils, strip heaters, baseboard heaters, thermostats, direct digital control systems, drive units, and circuits. City of Seattle Refrigeration Mechanic's License class A - requires three (3) years of experience conducting refrigeration repair and installation, as an apprentice to, or as a journeyman refrigeration and/or air conditioning mechanic; or two (2) years of training in a recognized school of technology, combined with one (1) year of experience in the refrigeration trade; or two (2) years full-tine experience in the refrigeration trade and graduation from a recognized trade school of refrigeration technology.