BLAST UNIT

PROBLEM TO BE SOLVED: To provide a blast unit 1 capable of realizing low noise. SOLUTION: A housing 3 is formed into a box shape having a size allowing storing of two centrifugal fans 2 in parallel, and has a partition 4 between both centrifugal fans 2 stored inside. A plurality of holes 7 are formed near a part where intervals between fan blades and both side surfaces 3a of the housing 3 and the partition 4 are narrowest. Thus, even when the clearance between the centrifugal fans 2 and wall surfaces of the housing 3 is decreased by miniaturizing the blast unit 1, noise having a frequency (resonance frequency) resonating with a resonance system for vibrating the air in the hole 7 parts can be absorbed, which has an effect on reducing peak noise generated by the rotation of the centrifugal fans 2. Especially, the plurality of holes 7 formed in both side surfaces 3a of the housing 3 and the partition 4 are preferably designed so that the number of the holes, a pitch (hole interval), a hole diameter, and the like have specifications capable of mainly absorbing noise of an order component of 'the number of fan blades × fan rotation speed'.