A respiratory assistance system including a humidification apparatus used for delivery of heated and humidified gases to a patient includes a humidification chamber with an associated heater and sensor, an inspiratory conduit with an associated heater and sensor, and an unheated patient interface, such as a face mask. A controller of the humidification apparatus is configured to determine a gas source and change the set point accordingly to maintain patient comfort regardless of the humidity level of the gas source.