In this study, an experiment was conducted assuming an infinite ceiling to predict horizontal propagation of ceiling flow in a large flat space. In addition, the applicability of the Alpert, Heskestad and Delichatsios equations, which are prediction equations for the temperature and velocity of ceiling flow, and the large flat space of this experiment was reviewed. As a result, the predicted value and the experimental value are matched in the range of r/H<5, but results of the experimental values are different with calculated values after that.
