Temperature effectiveness is the change in process fluid stream temperature divided by the difference between the hottest and coldest temperatures in the exchanger. If the required effectiveness is greater than 0.8, non-ideal fabrication or variable process conditions can significantly reduce performance of many exchanger types (shell-and-tube, plate-frame, plate-fin, etc.). Learn about applications where high effectiveness is expected, the factors which degrade effectiveness, and what a designer can do to ensure adequate performance.