A ship's container hold only with a mechanical ventilation system for carrying full of air cooled type reefer containers was the first attempt for us. Before an actual design and installation, a model test was carried out to verify that the system works in good order enabling a normal operation of the reefer containers After the ship's delivery to the Owner, an experimental on-board test was also carried out, Showing the system worked successfully and all reefer containers kept normal operation. Various kinds of data for future design and for further improvement of the system were obtained through the test.