Humidifier Water Balance

The app’s water balance calculation is a vital tool for assessing cathode humidifier efficiency and setpoint correction. It allows input of RH or dewpoint temperature, with water collection in mass or volume units. The outlet RH/dewpoint is calculated, and water volume (if used) is adjusted based on air vent temperature downstream of the condenser.

To ensure accuracy, the system should connect the stack cathode inlet pipe directly to the stack cathode outlet. A proportional value is often required to simulate the omitted stack pressure drop for correct back pressure. Prior to venting air, a condenser/cooler and water separator are essential for efficient water removal. A sufficiently sized container is needed to collect the separated water. Temperature data at the humidifier mix point (or outlet, if all air flows through the humidifier) and downstream of the condenser/cooler are required for the calculation.

Note that the calculation assumes an input air pressure of 200-kPa, which introduces minimal error in most systems.