- - WORK EXPERIENCE John Morrell Refrigeration Technician Feb - May, Sioux City, IA • Operated a duel stage anhydrous ammonia system • Took temperatures and performed water test • Took care of air compressors.- Wells Dairy, Inc. Refrigeration Techniciain Dec - Feb LeMars, IA • Operated a duel stage anhydrous ammonia system • Took care of air compressors, boilers and refrigeration system • Took water tests, daily temperature readings, HVAC systems and ammonia compressors - ... More