Exothermics SP Sinusoidal Plate Heat Exchangers are the flagship products of the Exothermics line. Our exclusive sinusoidal plate design provides maximum effectiveness and the highest performance available on the market today. High heat transfer effectiveness is produced by corrugating the heat transfer plates to achieve our proprietary sinusoidal wave pattern. The corrugated surface creates air flow turbulence as the air passes through the unit. Heat transfer is further enhanced by using a counter flow design. SP heat exchangers feature fully welded stainless steel construction for robust, durable performance, maximum efficiency and short payback time.