Factory-assembled, low charge ammonia refrigeration system requires much less refrigerant charge than that associated with traditional field-built systems. Consisting of self-contained ammonia refrigeration rooftop systems designed to ship in one- or two-piece modules, Evapcold offers simple plug-and-play installation. Other features include faster startups with less on-site labor required than field-built alternatives. Refrigeration system testing includes verification of many operational parameters under a range of conditions. They include thermal performance (cooling and heat rejection capacity); total energy consumption and component optimization; refrigerant charge volume; refrigerant recirculation rate; and operational excursions.