Apparatus for treating a respiratory disorder in a patient, the apparatus comprising: a respiratory pressure therapy device configured to generate a flow of air for treating the respiratory disorder, said flow of air being at a positive pressure with respect to ambient pressure; an air circuit adapted to transport said flow of air generated by said respiratory pressure therapy device to a patient interface, said air circuit having a proximal end connectable to said respiratory pressure therapy device and a distal end connectable to said patient interface; a nebuliser module located at or adjacent to said proximal end of said air circuit, said nebuliser module adapted to nebulise a liquid to form a nebula of said liquid, and to admit said nebula into said flow of air generated by said respiratory pressure therapy device; and a vaporiser located at said distal end of said air circuit, said vaporiser adapted to receive said nebula and further adapted to vaporise said nebula to form a humidified flow of air. Also, a method for treating a respiratory disorder in a patient, the method comprising the steps of: generating a flow of air for treating the respiratory disorder in a respiratory pressure therapy device, said flow of air being at a positive pressure with respect to ambient pressure; nebulising a liquid retained in a water reservoir to form a nebula of said liquid, and admitting said nebula to said flow of air; transporting said flow of air and said nebula over an air circuit; receiving said flow of air and said nebula in a vaporiser module; vaporising said nebula to form a vapour of said liquid; mixing said air flow with said vapour in said vaporiser module to form a humidified flow of air; receiving said humidified flow of air in a patient interface; and delivering said humidified flow of air to said patient for treatment of said respiratory disorder.