Few case studies have examined the actual operation of variable refrigerant flow systems. The installation conditions for each case, such as the number of indoor units connected, piping length, height difference, and refrigerant filling budget, are not fixed. Therefore, accurately grasping the changes in performance is difficult. Moreover, specifying the performance evaluation method is necessary because of the complex and diverse operating conditions for each case. The system performance intended by the air conditioning designer/builder is not attained because the actual driving situation differs for each property. Therefore, possible complaints of the system being “too hot” or “too cold” raise a concern.