An air heater coil (140) adapted to heat an airflow within a respiratory device (e.g. air delivery tube 116) comprising a plurality of loops or petals, each loop or petal arranged to overlap an adjacent loop or petal to form a rosette configuration adapted to cover substantially all or most of a cross-sectional area of an air flow path within the respiratory device. Preferably, the plurality of loops or petals are formed of resistive wire.
展开▼
