A controller can be configured to control a system for extracting liquid water from air comprising a thermal unit, a primary desiccant wheel, and a regeneration fluid path. The controller can comprise a sensor, a motor, and a microcontroller coupled to the sensor and the motor. The microcontroller can be configured to determine a water extraction efficiency based on at least one signal received from the sensor, and also can be configured to maximize the water extraction efficiency by adjusting a speed of the motor in response to the determined water extraction efficiency.