The HEA-S series air cooled chiller units, specifically designed for air conditioning (HVAC) applications, have a rather wide and various capacity range thanks to their 1-2-4-8 and 1 scroll compressor structure. The cooling capacity at models with multiple compressors are staged. Thus, both energy saving is ensured and the complete stoppage of the process in case of a defect is prevented. The best and advanced technology product components are used at the units. The compressor and fan groups have an equal aging feature under processor control.