mitsubishi electric ceiling concealed duct types he thin, ceiling-concealed indoor units of the PEY series are the perfect answer for the air conditioning requirements of buildings with minimum ceiling installation space and wide-ranging external static pressure. Energy-saving efficiency has been improved, thereby reducing electricity consumption and contributing to a further reduction in operating cost. Compact Indoor Units For all models, unit height are unified to 250mm. Compared to the previous model, the height size is reduced, allowing installation in tight spaces, such as ceiling cavities or drop-ceilings. Air Inlet The units with bottom inlet make more noise than those with rear inlet. It is recommended that the rear inlet be selected when install - ing the units i