A plant or refinery may include equipment such as reactors, heaters, heat exchangers, regenerators, separators, or the like. Types of heat exchangers include shell and tube, plate, plate and shell, plate fin, air cooled, wetted-surface air cooled, or the like. Operating methods may impact deterioration in equipment condition, prolong equipment life, extend production operating time, or provide other benefits. Mechanical or digital sensors may be used for monitoring equipment, and sensor data may be programmatically analyzed to identify developing problems. For example, sensors may be used in conjunction with one or more system components to detect and correct maldistribution, cross-leakage, strain, pre-leakage, thermal stresses, fouling, vibration, problems in liquid lifting, conditions that can affect air-cooled exchangers, conditions that can affect a wetted-surface air-cooled heat exchanger, or the like. An operating condition or mode may be adjusted to prolong equipment life or avoid equipment failure.