The authors proposed floor thermal storage system which consisted of deck plate slab, guide plate and jelled water thermal storage body above the slab forming air flow channels in the previous reports. In this study, experiments were conducted by changing air flow directions and its flow rates, charging and discharging heat capacities and heat flow rates through floor and ceiling were measured. In addition, the temperatures of slab and jellied water thermal storage body were calculated and compared with the results of the experiments. Then the effectiveness of installed jellied water thermal storage body was identified by the increase of heat capacity stored and the decrease of heat loss through floor.
