A low-noise blower that can provide a smooth transition of fluid flow and reduce audible noise, which can disrupt a patient's rest and cause fatigue to patients and caregivers, the blower having an impeller and a housing, the impeller with an impeller plate and a plurality of blades each attached to the impeller plate, and the housing with an impeller cavity and a collector, where a slot with inclined surfaces extends between the impeller cavity and the collector.
