A new method has been developed for simulation of heat regenerators in periodic operation. The procedure is based on describing the system by a number of backmixed cells in series, in contrast to the differential equation formulation used in earlier studies. The method is highly efficient computationally and the calculation of thermal efficiency and temperature profiles in the system is reduced to the solution of a simple set of linear algebraic equations. The validity of the method is established by comparing it with other solution procedures. Finally, some illustrative results are presented to show the effect of switching time, normalized variance of the system, and mode of operation.