Furnace blower having sound attenuation

摘要

A blower fan assembly is provided which includes a blower housing, an exhaust port having an air passage connected to the housing and an impeller assembly rotatably received within the housing. A sound attenuator is also provided to be received in the exhaust port. The attenuator includes at least one edge which extends into the housing to provide a gradual cutoff point. Air moving ahead of the rotating impeller vanes is partially redirected through the exhaust port by the attenuator. Remaining air is directed over and around the attenuator and is forced out of the housing at the cutoff point created where the exhaust port joins the housing. The redirection of air alleviates compression/decompression at the cutoffs thereby reducing the pulsing noise associated therewith.