This paper discusses estimation methods of steady state and unsteady state heat output in hot water floor heating systems. It becomes clear that Kollmar-Liese's method which has been popularly used, underestimates steady state heat transfer rate from the floor. The authors propose a new simple estimation method by applying DOE(Design of Experiments) method. On the other hand, there has been no simple estimation method for unsteady state two-dimensional heat transfer in floor heating systems. In this paper, precise responses of heat transfered from the floor obtained by two-dimensional 'calculations are analyzed and classified, and representative responses are expressed by exponential polynomial approximation.
