A call for humidity signal may activate a water valve of a humidifier to cause water to flow onto a humidifier pad within the humidifier. In some examples, a controller may activate the water valve in a pattern such that most of the water evaporates, rather than flowing to a drain system, yet still provides the requested humidity level. In some examples, the controller is configured to cause the water valve to deliver water to the humidifier pad in a water delivery pattern having a controlled period and a controlled duty cycle.