Handling refrigerant, working with natural/propane gas, basic pipe fitting, soldering/brazing, chillers (scroll, screw, reciprocating and centrifugal), walk ins, reach ins, package and split system A/C's, ice machines, air handlers, cooling towers, exhaust fans, make up air (MUA) units, return fans, variable air volume (VAV's), re heat coils, ductwork, heat pumps, furnace