The influence of cooling requirements, chassis resistance, and fan selection on noise emission

Cooling fans are a ubiquitous and often dominant source of noise emission for many products. Cooling requirements and chassis resistance influence not only the selection of the cooling fan, but also set a lower bound on noise emission. Typical manufacturers´ noise emission data, obtained under optimal inflow free-air conditions, is of dubious value. Unpleasant surprises can occur when initial prototypes with real-world fan loading and inlet conditions collide with cooling requirements and chassis design. This paper describes methods for anticipating and optimizing noise emission of a product at a very early design stage.