The impeller spins within a housing with an inboard and outboard channel. It is from this configuration that the name side channel blower is drawn. As the impeller blades pass the inlet port, they draw air in. The impeller rotation pushes air outward and forward into the channels. The air then returns to the base of the blade. As the impeller spins, the process repeats. This regeneration gives the blower its pressure / vacuum capabilities.