Abstract: This invention provides a rotary heat regenerator which includes a regenerator wheel in which the regenerator matrix is formed of at least one strip of synthetic organic plastic wound onto a central hub, with suitable spacing means being formed in the strip to form gas passages. Inexpensive means is provided to stiffen the wheel to impart lateral strength and rotational stability. In one embodiment of the invention, radial portions of the face of the matrix are fastened together by fusing, by an adhesive, or both. In another embodiment of the invention, radial apertures are formed in the wheel by forcing a heated tool, radially into the wheel periphery so that the surfaces of the strip layers of the matrix are fused together, forming a hollow cylinder bounded by a continuous layer of plastic. To impart further rigidity to the wheel, the hollow cylinder may be filled with a reinforcing rod of plastic or metal.